Design Source and Material

Students‟ Reference Material DSM/SRM/1


INDEX

Content Page

Unit – I ............................................................................................................................................ 4

Lesson - 1: Tiles ............................................................................................................................. 5

Lesson - 2: Plastering .................................................................................................................... 7

Lesson - 3: Paint .......................................................................................................................... 11

Lesson - 4: Wallpaper ................................................................................................................. 21

Lesson - 5: Fabric and Other Wall Coverings .......................................................................... 24

Unit – II ........................................................................................................................................ 29

Lesson - 6: Floor Finishes ........................................................................................................... 30

Lesson - 7: Bricks ........................................................................................................................ 35

Lesson - 8: Building Tiles ........................................................................................................... 46

Lesson - 9: Stone .......................................................................................................................... 53

Lesson - 10: Carpets and Rugs ................................................................................................... 60

Lesson - 11: Resilient Floor Coverings ..................................................................................... 63

Unit – III ...................................................................................................................................... 70

Lesson - 12: Fabric Construction and Fibres ........................................................................... 71

Lesson - 13: Vegetable Fibres..................................................................................................... 75

Lesson - 14: Man-Made Fibres .................................................................................................. 78

Lesson - 15: Upholstery Materials ............................................................................................. 86

Unit – IV ....................................................................................................................................... 94

Lesson - 16: Accessories .............................................................................................................. 95

Lesson - 17: Wall Accessories..................................................................................................... 97

Lesson - 18: Sculpture and Table Ornaments ........................................................................ 103

Lesson - 19: Window Treatments ............................................................................................ 109

Lesson - 20: Types of Window Treatments ............................................................................ 113

Lesson - 21: Window Treatment Hardware ........................................................................... 124

Unit – V ...................................................................................................................................... 128

Lesson - 22: Wood and Wood Based Products ...................................................................... 129


Lesson - 23: Classification of Timber ...................................................................................... 132

Lesson - 24: Seasoning of Timber ............................................................................................ 136

Lesson - 25: Timber Trees of India ......................................................................................... 140

Lesson - 26: Wood Based Products ......................................................................................... 146

Lesson - 27: Glass Terminology ............................................................................................... 152

Lesson - 28: Glass ...................................................................................................................... 156

Lesson - 29: Application of Glass in Interiors ........................................................................ 162

Lesson - 30: Glazing .................................................................................................................. 166

Lesson - 31: Metals .................................................................................................................... 171

Lesson - 32: Aluminium ............................................................................................................ 173

Lesson - 33: Other Metals ........................................................................................................ 175

Lesson - 34: Plastics .................................................................................................................. 180

Supplementary Material / Reference Books ........................................................................... 193


Unit – I

Wall Treatments

Lesson-1: Tiles

Lesson-2: Plastering

Lesson-3: Paints

Lesson-4: Wall Paper

Lesson-5: Fabric and Other Wall Coverings


Lesson - 1: Tiles

Objectives:

To examine the role of walls in a building and think of the various walls in their surroundings

and state their function.

Structure:

1.0 Introduction

1.1 Wall Tile

1.2 Ceramic tiles

1.3 Mosaic tiles

1.0 Introduction

Typical wall systems include wood or metal studs, wood post and beam framing, steel and

reinforced concrete framing, and masonry. Interior walls and partitions may be load bearing or

non-load bearing. Wall surfaces must be able to accept desired finishes.

1.1 Wall Tile

A wall tile is any tile used primarily in applications other than floors. The most prevalent of these

are "standard wall tiles," which also go by the term "four-and-a-quarter," since they are

approximately 4 ¼ inches square, 6" and 8" are also popular.

Four-and-a-quarter tiles are those

which have been used in

bathrooms since the advent of

inside plumbing. Many

companies make them, and thus

there are myriad colours and

textures available.

Trim pieces or "shapes" are

available for every style of

standard wall tile made. This is

important when it comes to

building showers and other

structures that require outside

corners and edges.

Four-and-a-quarter tiles are almost always formed from "slip," the white ceramic clay used in

figurines. The tiles are water-resistant but not water-proof. There are a number of porcelain tiles

which are also designed to be used on walls and surfaces other than floors.


1.2 Ceramic Tiles

There are several options of

glazed and unglazed ceramic

tiles for surfacing walls. Wall

tiles have low impact

resistance and are typically

glazed. Install tiles from floors

to ceilings on wet walls, such

as showers, and at least

wainscot height behind

lavatories and toilets is preferred.

1.3 Mosaic Tiles

Mosaics are any tiles, glazed or unglazed, that measures 2 inches square or less, although they

don't necessarily have to be square. Some of them, in fact, are hexagonal in shape and others are

rectangles. It doesn't matter what the tiles are made of, however most mosaics are made from

porcelain, and most of them are left unglazed.


Lesson - 2: Plastering

Objectives:

To provide a true, even, smooth and finished surface to the work and improve the appearance

and protect the surface from atmospheric influences, to cover defective workmanship and to

provide a covering for the unsound and porous material.

Structure:

2.0 Introduction

2.1 Objectives of plastering

2.2 Procedure of plastering

2.3 Stucco plastering

2.4 Pointing

2.4.1 Procedure of pointing

2.4.2 Forms of plastering

2.0 Introduction

Plastering is an art of covering rough

walls and uneven surfaces in the

construction of houses and other

structures with a plastic composition,

called plaster. Plastering, in general, is

not required for good brickwork, made

of well-burnt bricks of neat stone

masonry constructed of durable stones

and good mortar.

2.1 Objectives of Plastering

The principal objectives of plastering are:

1. To provide a true, even, smooth and finished surface to the work and improve the

appearance.

2. To protect the surface from atmospheric influences.

3. To cover defective workmanship.

4. To provide a covering for the unsound and porous materials.


2.2 Procedure of plastering:

i. Preparation of surface: All the joints and surface of the masonry are well cleaned with a

wire brush and care is taken to see that they are free from oil, grease, soot etc. Holes and

hollows, if any, are properly filled and projections more than 1½ cm beyond the general

surface of the wall are knocked off to make the surface of the wall uniform. In case of old

brick walls, the bricks are pricked over so as to expose a new rough surface. Finally the

mortar joints and surface of the wall are washed, wetted with clean water and kept wet

for at least 6 hours prior to the application of plaster.

ii. Ground work for plaster: To acts as a guide for the thickness of plaster, vertical strips or

ledges, of plaster, called screed or bands are formed at the ends of the surface to be

covered and at intervals of about 1.5 metres across it, and levelled upto strings stretched

at the distance from the masonry. The screeds are usually 15 cm in width and extend

from the top of the wall to the bottom. The screed thus formed form the ground work for

the application of plaster.

iii. Application of plaster coats: The cement plaster may be applied either in one coat or two

coats.

The first or rough coat of plaster usually comprises of 1 part of Portland cement and 3

or 4 parts of sand by volume. The surface of the wall is first prepared as described for

lime plastering and vertical screeds, 15 cms in width are formed on the wall surface at

suitable intervals, The spaces or bays between the screeds are applied with cement

plaster with mason's trowels and the plaster is levelled by means of flat wooden floats

and wooden straight edges. Finally the surface is polished without sprinkling water.

If second or fine or flushing coat is to applied, the surface of the first coat is not

polished but roughened to give a key to the second coat of plaster. Second coat

consists of a paste of pure Portland cement mixed with sufficient quantity of water

and is applied in a thin layer over the moist and damp first coat, well trowelled and

rubbed perfectly smooth.

To develop adequate strength and hardness the finished plastered surface (whether

one or two coats) is kept wet by sprinkling water for at least a week.

2.3 Stucco Plastering

Stucco plaster is mixture of lime, white stone, gypsum and oxides for colouring.

The first coat is very coarse; the second is finer and forms a smooth even surface, while the final

is the finishing coat. The usual proportions in the first two coats are: Cement 1 part, sand 3 parts,

hydrated lime 10 per cent and in the final coat, cement 1 part, sand 2 parts, coloured cement 1

part or any metallic oxide for colour.

It is an excellent decorative plaster used on both interior and exterior walls.


2.4 Pointing

Pointing is the an of finishing the mortar joints of the

walls or similar structure with either cement mortar or

lime mortar in order to protect the joints from

atmospheric agencies and also to improve the

appearance of the structure.

Pointing is restored to:

i. Where a uniform and smooth surface is not

required.

ii. Where the exhibition of the natural beauty of the materials such as stone blocks, bricks

etc., used in construction is to be made.

iii. Where the materials used in construction can withstand effects of weather.

iv. Where the workmanship is quite good.

2.4.1 Procedure of Pointing

Prior to pointing, all the mortar joints on the face are raked out by a special pointing tool to a

depth of about 1¾ cm to provide an adequate key for the fresh mortar used for pointing.

All the loose mortar and dust are then brushed out of joints and the wall surface is well washed,

wetted with clean water and kept wet for a few hours.

The joints after being prepared are filled with lime or cement mortar with a small trowel. The

mortar is well pressed into the joints to ensure a solid contact with the internal old

2.4.2 Forms of Pointing

i. Struck joint pointing: Refer Fig. 6.5 (i). The upper

portion is inside the face of masonry by 12 mm

while the bottom portion of the pointing is flush

with masonry.

ii. Tuck pointing: Refer Fig. 6.5 (ii):

The joint, after having been raked, is filled with cement

mortar.

A groove 6 mm wide and 3 mm deep is formed along the centre of the joint while the

previously applied cement mortar is soft.

The groove is filled with lime putty which projects

by 3 mm. Lime putty is sometimes replaced by

cement.

The pointing gives a pleasing appearance.

i. Recessed joint pointing: Refer Fig. 6.5 (iii).

Mortar is pressed behind the walls.


It is used for high-class masonry work.

ii. Flush pointing: Refer Fig. 6.5 (iv)

It is suitable for brick as well as stone masonry.

The raked portion of the joint is filled with mortar

and surface made flush to the masonry for

trowelling.

iii. V-groove jointing : Refer Fig. 6.5 (v)

It derives its name for its shape.

It is suitable for rubble and ashlar masonry work.

iv. Keyed joint pointing: Refer Fig. 6.5 (vi)

After filling the joint with mortar a semi-circle is

formed inside the pointing by some tool.

The pointing gives an elegant appearance.

v. Weathered joint pointing: Refer Fig. 6.5 (vii)

As the name suggests, this type of joint gives adequate protection against weathering.

However, it requires comparatively large quantity of water.


Lesson - 3: Paint

Objectives:

To provide pleasing, colourful and decorative appearance to the surfaces, to protect the

surfaces from the weathering effects of the atmosphere and actions by other liquids, fumes and

gases and to prevent corrosion of metallic surfaces

Structure: 3.0 Introduction

3.1 Definition of paint

3.2 Functions of paint

3.3 Constituents of an oil paint

3.3.1 Base

3.3.2 Vehicle

3.3.3 Pigment

3.3.4 Thinner

3.3.5 Drier

3.3.6 Inert filler

3.3.7 Antiskinning agent

3.3.8 Plasticizer

3.4 Preparation of an oil paint

3.5 Characteristics of a good paint

3.6 Types of paints

3.6.1 Oil paint

3.6.2 Cement paint

3.6.3 Emulsion paint

3.6.4 Enamel paint

3.6.5 Luminous paint

3.6.6 Silicate paint

3.6.7 Anti-corrosive paint

3.6.8 Plastic paint

3.7 Painting a new woodwork

3.8 Painting of old woodwork

3.9 Painting of plastered surfaces

3.10 General Precautions in the process of painting


3.0 Introduction

The paints are (coatings of fluid materials) applied over

the surfaces of timber and metals as protective coatings.

Metals will corrode, wood will warp and decay, concrete

and masonry may retain corrosive dust and finally

disintegrate unless they are protected by some sort of

coatings. In addition, coatings of paint also serve the

purpose of decoration, sanitation and improved

illumination.

The varnishes are transparent or nearly transparent

solutions of resinous materials and they are applied on

unpainted furniture and other woodwork to decorate the

surfaces and protect them against harmful effects of

atmosphere. Painted surfaces are varnished to enhance the

appearance of the paint and to increase its durability.

The distempers are comparatively cheap decorative paints

for walls and ceilings. They are less durable than oil or

emulsion paints. They are applied on brickwork, cement

and lime plastered surfaces and building boards such as

plasterboard and insulating boards.

3.1 Definition of Paint

Paint, as usually defined, is a dispersion of pigments in a

drying oil, with addition of driers and thinners, the former

accelerate film formation and hardening, the latter to

allow ease and uniformity in brushing and spraying. To

reduce the defect of cracking in films formed by paints

and also to get smooth film from paint plasticizers are also

added.

3.2 Functions of Paints

The functions of applying coats of paints to the surfaces

of timber, iron or steel work in the engineering field are as

follows:

1. To protect the surfaces from the weathering

effects of the atmosphere and actions by other

liquids, fumes and gases.

2. To provide pleasing, colourful and decorative

appearance to the surfaces.

3. To prevent decay of wooden members (by rot).

4. To prevent corrosion of metallic surfaces.

5. To provide a smooth surface for easy cleaning.


3.3 Constituents of an Oil Paint and their Functions

Following are the constituents/ingredients of an oil paint:

3.3.1 Base

The base is a principal constituent of a paint and possess the binding properties. The commonly

used bases are: white lead, zinc white, red lead, iron oxide, titanium white and lithopone.

The base performs the following functions:

i. It gives body to the paint.

ii. It reinforces the film paint after it has dried i.e. makes the film of the paint harder and

more resistant to abrasion.

iii. It minimises shrinking cracks usually formed in drying.

iv. It prevents penetration of the paint to the underlying surface.

3.3.2 Vehicle:

Vehicle or carrier is the liquid which carries solid materials of the base and helps them to spread

evenly on the surface to be painted. It is also known as the drying oil. It acts as a binder to the

base and pigment and allows it to be applied. It should dry out on exposure to atmosphere.

The various vehicles are: Linseed oil, soyabean oil, dehydrated castor oil, fish oil, casein, latex

emulsions, varnishes etc.

The vehicle performs the following functions:

i. It holds the pigment to the surface.

ii. It forms a protective film by evaporating or by oxidation and polymerisation of the

unsaturated constituents of the drying oil.

iii. It acts as a binder for the base and the pigment.

iv. It provides glow to the painted surface.

3.3.3 Pigment:

A colouring pigment or strainer is a finely divided solid material which provides required shade

and colour to the paint. The best pigments do not change colour when exposed to heat.

Following are the functions of a pigment:

i. It provides required shade and colour to the paint.

ii. It reduces the intensity of development of cracks due to drying of the vehicle.

3.3.4 Thinner:

A thinner or solvent is a volatile substance that is added to the paint to make its application easy

and smooth.

The various types of thinners used in the industry are:

i. Aliphatic hydrocarbons such as mineral spirits, napthas and other petroleum fractions.


ii. Aromatic hydrocarbons such as toluol, xylol, methylated naphthalene.

iii. Turpentine and dipentine.

Thinners perform the following functions:

i. They dissolve the film forming material.

ii. They suspend pigments.

iii. They thin the concentrated paints for proper handling.

iv. They evaporate quickly and thus facilitate the drying of paint.

3.3.5 Drier:

A drier is a substance which acts as catalyst and quickens the drying of the vehicle used in the

paint.

Driers used are heavy metallic soaps such as napthenates, resinates, octates, linoleats etc. of Co,

Mn, Pb and Zn. Quantity used is very little.

3.3.6 Inert filler:

It is an adulterant usually mixed in an oil paint to modify its weight, to improve its durability

and to effect economy in the cost of base used.

The commonly used fillers are: Silica, charcoal, barytes, gypsum etc.

3.3.7 Antiskinning agent:

Antiskinning agents are used to prevent gelling and skinning of the paint. These are generally

polyhdroxy phenols.

3.3.8 Plasticizer:

Plasticizers are used to give elasticity to the .film and they minimize or prevent cracking. Some

oils are used as plasticizers.

3.4 Preparation of an oil Paint

The preparation of an oil paint involves the following steps:

The base (usually white lead) is first thoroughly ground in the vehicle (linseed oil) so as to form

a thick paste.

The thick paste is then thinned down by adding a suitable quantity of the thinner/solvent to

impart necessary workability to the paint.

The colouring pigment well ground and mixed or with drier is then added in the base already

prepared (as mentioned above) and thorough mixing is done to get the required paint. Grinding

in roller mills is an important operation in the mixing of paints.

While preparing an oil paint following precautions should be observed:

i. All the ingredients should be properly mixed so as to avoid spots on the work to be

painted.

ii. Drier should not be added to a paint until it is about to be used.


iii. Excess of drier should not be used in the paint as it injures the paint.

iv. The use of more than one kind of drier in the same paint should be avoided.

v. In order to avoid the discolouring of litharge (oxide of lead), sulphate of manganese is

frequently used with zinc paints.

3.5 Characteristics of a Good Paint

i. Following are the characteristics of a good oil paint.

ii. It should be able to resist the atmospheric conditions to which it will be put.

iii. It should have high hiding power and the required colour.

iv. It should dry fairly quickly.

v. It should form a tough, elastic and durable film when dry.

vi. It should resist corrosion when applied on a metal.

vii. It should not crack on drying.

viii. The film produced by the paint should be glossy and washable.

ix. Paint should have necessary consistency for a particular purpose for which the paint is to

be used.

x. It should to be fluid enough to be spread in a thin coat with a brush.

xi. It should not show brush marks after drying.

xii. It should be free form defects of chalking, cracking and blistering.

xiii. It should have lasting pleasing appearance.

3.6 Types of Paints

The different types of paints are:

3.6.1 Oil paint:

i. This is an ordinary paint, cheap and easy to apply.

ii. It is generally applied in three coats namely: Primes, undercoats and finishing coats.

iii. It possesses good opacity and low gloss.

Oil paint should not be applied during humid and damp weather.

3.6.2 Cement paint:

i. Cement paint consists of cement and hydrated lime mixed along with a colouring

pigment.

ii. An inert filler (sand) is often added to make the paint economical.

iii. Cement paints are available in powder form and require mixing only in water before use.

Preparation of the paint: In order to prepare this type of paint, the cement is first intimately

mixed with white and colouring pigments. The other ingredients are added by thoroughly stirring

in a suitable container.


The cement paint is applied in two coats.

Before the first coat is applied, the surfaces are wetted to even and control suction and to assist

the hardening process of the cement paint. Liquid water should not be present on the surface

when the paint is applied.

The second coat is applied not less than 24 hours after the first coat. It is essential to keep the

surface wet after the final coat for about two days by frequent splashing of water to get the best

performance.

Advantages of cement paints:

Following are the advantages of cement paints:

i. Can be applied with a brush or sprayer.

ii. Impart pleasing appearance to the structure.

iii. Can be applied over new and damp walls which cannot be painted over with oil paints

until they are sufficiently dried.

iv. They can also be washed.

v. They do not flake or peel off and are unaffected by climatic conditions.

vi. They provide a smooth mat finish without any brush mark.

vii. They prove to be economical as compared to the oil paints.

viii. They are suitable for painting fresh plaster having high alkalinity.

Uses: Cement paints .are now being commonly used as a lasting finish on outer surfaces of walls

and ceiling in residential as well in public buildings etc.

3.6.3 Emulsion paint:

It consists of polyvinyl acetate and synthetic

resin as binding materials.

It is easy to apply and dries quickly (in about

I~ to 2 hours) .The paint possesses excellent

alkali resistance.

The colour of the paint is retained for-a long

period.

The surface of paint is tough and it can be

cleaned by washing with water.

Uses: These paints are mostly employed for painting steel and woodwork which is to be built in

masonry.


3.6.4 Enamel Paint:

Enamel point consists of white lead or zinc white ground

in a small quantity of oil and mixed with petroleum spirit

and resinous matter.

Properties:

i. It dries slowly and forms a hard and durable

surface.

ii. It is not affected by cold and hot water.

iii. It is a little costlier but economical in the long

run.

iv. It is resistant to steam, fumes, acids and alkalise.

v. It is durable and forms a tough, elastic and glossy film.

Uses: Employed for painting door and window frames and protecting timber and other wood-

based products. These paints are used for both external and internal works.

3.6.5 Luminous paint:

It contains calcium sulphide with varnish. The surface on

which this paint is applied shines like radium dials of

watches after the light source has been cut-off.

Uses: The luminous paint is applied on the surfaces

which are free from corrosion or any other lead paint.

3.6.6 Silicate Paint:

It is a prepared by mixing calcined and finely ground silica with resinous

substances. The drier used with the paint should be of a special silicate

drier type.

Properties:

i. It can stand extreme heat.

ii. It adheres firmly to brickwork also.

iii. It is not affected by alkalise.

iv. The paint has no chemical action on metals.

v. The paint when dried forms a hard durable surface.

Uses: The paint can be directly applied on brick, plaster or concrete surface; these surfaces

should be made wet before the paint is applied. The surface should not be painted with silicate

paint in hot weather.

3.6.7 Anti-corrosive paint:

It consists of oil and a strong drier. A pigment (such as chromium oxide or lead or red lead or

zinc chrome) after mixing with some quantity of sand is added to the paint.


Properties:

i. It has a black appearance.

ii. It is durable.

iii. It is cheap.

3.6.8 Plastic paint:

The paint contains necessary variety of plastics. It is available in the market under different trade

names. The plastic paint can be applied either by a painting brush or spray painting.

Properties:

i. The paint possesses pleasing appearance and is attractive.

ii. These paints are the finest types of paints.

iii. They provide durable film on drying.

Uses: These paints are widely used for auditoriums, show rooms,

cinema halls etc. Following points are worth noting regarding the

use of plastic emulsion paints:

i. As these paints cannot resist the attack of enemies of paints (e.g. salts, dust, gases carried

by air. fog, rain etc.), these should be mainly used for interior jobs.

ii. The surface to be painted should be cleaned of all dust particles and rubbed with sand

paper if necessary, if required levelling putty may be applied.

iii. These paints are water based and hence they are not suitable for metallic surfaces. These

paints are not water repellent and may develop some fungus growth in unfavourable

circumstances.

iv. The thickness of coat should neither be too thin nor too thick.

v. The painted surfaces need to be washed with wet cloth lightly at least once in a month,

failing which the paint may loose its good appearance due to adherence of the dust

particles.

3.7 Painting of New Woodwork

Painting is the process of applying suitable paint with the help of painter's flat brush or "

spraying. Painting' involves the following steps:

i. Preparation of surface: Prior to the application of paint to any woodwork it should be

seasoned thoroughly. .The surface to be painted should be carefully cleaned and rendered

smooth.

ii. Knotting: It consists of covering up all the knots with substance through which the resin

cannot come out.

iii. Priming Coat: it is also called primary or first coat of painting and is applied after the

knotting is finished. It entails the following advantages:

a) It provides protection to the surface from the corrosive action of the atmosphere.


b) Due to this coat some of the paint sticks to the surface over which the subsequent coats

can be applied smoothly.

c) It form a hard and opaque covering, filling the pores of the wood.

1. Stopping: It is carried out after the priming coat is applied. It consists in rubbing down the

primed surface with either pumice stone or glass paper and filling any holes or cracks with

glazier's putty.

2. Application of succeeding coats of paints: After the steps mentioned above have prepared

the surface, the woodwork is then painted by applying at least two (preferably three) coats pf

paints. Prior to the application of any succeeding coat, the previous one is dried and is gently

rubbed down with glass paper and rendered smooth. Each coat is applied in longitudinal

direction and care is taken that brush marks are not left on the painted surface. The final coat

is called the finishing coat.

3.8 Painting of Old Woodwork

Repainting of old woodwork consists of washing the surface thoroughly

with soap and water, rubbing down smooth with pumice stone and

stopping with putty all the holes and cracks. Two three coats of oil paint

are then applied carefully so that no brush mark is visible on the surface.

No succeeding coat is applied until the previous one gets dried.

3.9 Painting of Plastered Surfaces

Painting on a freshly plastered surface should be avoided for at least six

months. The surface should be white or colour washed in the first instance otherwise the alkalise

present in the plaster will destroy, bleach and discolour the paint and also prevent it from drying.

On drying of the new-plastered surface, it should be treated with dilute sulphuric or hydrochloric

acid and then washed with water. The surface is then given a coat of sizing (glue mixed with

water). It will fill up the cracks and reduce the suction of the paint.

Before applying the paint, the surface is may also be given a coat of linseed oil. After the

absorption of the oil on the surface, filling of cracks if any, is done by preparing a paste of chalk

powder, plaster of paris and the paint to be used the entire surface is then smoothened by rubbing

it with sand paper.

The surface thus prepared is then given four coats of paint

The first two coats of the paint consist of white lead and boiled linseed oil.

The third coat may be of white lead tinted to approach the desired colour and mixed with

raw or boiled linseed oil.

The last coat may consist of large proportion of turpentine oil with a little varnish.

Note: Ready made or nearly mixed paints are also available in the market which can be applied

directly on the newly plastered surfaces.


3.10 General Precautions in the Process of Painting

While painting any surface, the following precautions should be observed:

i. The surface to be painted should be perfectly clean and dry.

ii. Painting work should be carried out in dry, warm weather after a dry spell.

iii. Each coat of paint should be of moderate thickness for drying.

iv. The undercoats and first coats must invariably be allowed to dry properly before applying

the final coat.

v. Always rub down lightly between coats.

vi. For exposed works, boiled linseed oil should be used.

vii. The work should be planned in such a way that the specific part (door, ceiling) is

completed in the same day.


Lesson - 4: Wallpaper

Objectives:

Good substitute for the tapestries, brocades, carpet mountings, murals and panelling that were

expensively and slowly worked upon for the wealthier houses.

Structure:

4.0 Introduction

4.1 Types of papers

4.1.1 Lining paper

4.1.2 Pitch paper

4.1.3 Washable papers

4.1.4 Vinyl papers

4.1.5 Blown or Expanded Vinyl Papers

4.1.6 Foamed Polyethylene Coverings

4.1.7 Ready-Pasted Wallpapers

4.1.8 Finishing and decorative paper

4.1.9 Hand-made paper

4.0 Introduction

Wallpaper is typically used for residential projects due to

its limited resistance to wear and maintenance.

Originally wallpapers were developed to substitute for the

tapestries, brocades, carpet mountings, murals and

panelling that were expensively and slowly worked upon

for the wealthier houses. After the advent of the printing

press, techniques developed until the first black and white

wallpapers were produced in the 16th Century. Today,

apart from cost, there are other reasons for seriously

considering wallpaper as an interesting and suitable

decorative material, not least its ease of application and

its relatively temporary nature, since ideas and occupation

of premises seem to change with increasing rapidity.

Besides the more common printed papers, thickly woven

grass cloths, luminous metallic compounds and rich

flocks, looking like velvet cloth, can be found among the

seemingly limitless wallpaper stocks of today.


4.1 Types of Papers

4.1.1 Lining Papers

Lining Papers are important. When used either vertically or horizontally (cross-lined) they form

a good base on which to hang the finishing decorative wallpaper. As mentioned above, when the

base wall is uneven, or the final paper is of a delicate nature, this helps to achieve a better finish

and enhance its wear ability. With very heavy papers, or a particularly smooth and dry surface to

start with, they can occasionally be dispensed with. Lining papers are available in various

weights, and should butt jointed - edges should meet and not overlap.

4.1.2 Pitch Papers

Pitch Papers consist of a thin film of bitumen sandwiched between two sheets of tough brown

paper, or cartridge paper coated with pitch, that are used to withhold or stop damp penetration.

4.1.3 Washable Papers

Washable Papers are ordinary wallpapers coated with a

thin transparent glaze of PVA (polyvinyl acetate). They

may have a matt or gloss finish and are ideal for kitchens

or bathrooms as they can be washed down with a clean

sponge and soapy water. They should not be scrubbed as

this can damage the coating.

4.1.4 Vinyl Papers

Vinyl Papers consist of a layer of vinyl on which the design is printed. The printed design and

vinyl are then fused by heat to give a tough, impervious paper ideal for kitchens, bathrooms and

playrooms. Because they tend to trap moisture against the wall, they should be hung using a

fungicidal paste.

4.1.5 Blown or Expanded Vinyl Papers

Blown or Expanded Vinyl Papers are thicker

and more durable than ordinary vinyls, and

suitable for use in areas subjected to heavier

wear.

4.1.6 Foamed Polyethylene Coverings,

Foamed Polyethylene Coverings trade named "Novamura", are foam plastic coverings with no

backing paper. They produce an attractive, lightweight wallcovering with a soft, warm finish, but

are unsuitable for areas which take heavy wear.

4.1.7 Ready-Pasted Wallpapers

Ready-Pasted Wallpapers are now very common and, while naturally more expensive than

normal wallpaper, are a real boon to the DIY decorator. A carefully calculated layer of adhesive

already containing fungicide is applied to the back of the paper during manufacture, and it is then

a simple matter to measure and cut the strips to size and immerse them in water for the duration


recommended by the manufacturers before applying them directly to the wall, thus obviating the

necessity for pasting brushes and tables, and the messy mixing and applying of adhesive.

Borders have become almost an art form, allowing highly individual designs at low cost.

4.1.8 Finishing or Decorative Papers

Finishing or Decorative Papers generally have patterns which are either hand- or machine-

produced and can be textured in some form. With hand-printing each pattern colour is done

individually and allowed to dry. Wooden blocks or silk screens are used, and it is possible to tell

the difference from the machine-printed type, which applies up to 20 colours at a time with no

drying time in between, because, in the latter, merging occurs and the colour collects more

thickly at the edges. The ground (the base colour) also tends to show through.

4.1.9 Machine-printed papers

Machine-printed papers are printed with rollers to give a

consistent colour and pattern matching. The cheaper papers may

stretch or distort when wet and shrink when drying.

4.1.10 Hand-made papers

Hand-made papers are more delicate, costly and awkward to

hang. They may tear when wet and, as the hand-printing process is

not as accurate as machine printing, they can be more difficult to

match. Care should be taken to avoid paste smears on the surface.


Lesson - 5: Fabric and Other Wall Coverings

Objective:

To list and compare wall treatments used in interiors.

Structure:

5.0 Introduction

5.1 Wood panelling

5.2 Gypsum board

5.0 Introduction

Fabric wall coverings can be beautiful wall

finishes that are typically used in upscale spaces

with low traffic. Conference rooms and areas that

require speech privacy are good candidates for

fabric wall coverings. The follow applies to fabric

wall coverings:

Fabric wall coverings usually require a paper

or latex backing for stability and protection

from glues seeping through the fabric.

Install acoustical wall coverings in areas

where acoustical properties are important.

Upholstered wall coverings are a field installed wall finish in which the fabric covers a frame

that attaches to the wall. The selected fabric should be compatible as a wall treatment.

Designers should typically avoid nylon, rayon and viscose in these applications due to

sagging.

5.1 Wood Panelling

Wood panelling is an expensive wall treatment,

and therefore is usually applied to upscale

spaces. Wood veneer wall coverings give

luxurious looks without the expense of wood

panelling. The veneer can be installed finished or

unfinished, and since veneers are so thin, it is

imperative that substrates be very smooth.


5.2 Gypsum board

Gypsum board is installed as the wall substrate in most commercial interior projects. Gypsum

board is also referred to as wallboard, sheet rock and drywall.


Summary:

This unit involves the choice of wall finishes in interiors, factors such as: - personal tastes,

condition of the walls, cost, use of the room, desired effect, size and shape of the room,

maintenance, ease and cost of installation, decorative theme, and energy conservation and all

about the texture, colour, scale, and wall treatments to determine the effect created in a room

and construction and surfacing materials such as: panelling, plaster, wood, and masonry

Revision points:

Wall treatments that include the points such as: paint, wallpaper, fabric, cork, ceramic tile,

mirror, wood panelling, brick, and glass. And about the texture, colour, scale, and wall

treatments to determine the effect created in a room and construction and surfacing materials

such as: panelling, plaster, wood, and masonry.

Key Words:

Ceramic Tiles: - ceramic tiles are glazed and unglazed tiles for surfacing walls. These tiles have

low impact resistance and are typically glazed.

Plastering: - Plastering is an art of covering rough walls and uneven surfaces in the construction

of houses and other structures with a plastic composition, called plaster.

Screed or bands: - vertical strips or ledges, of plaster, called screed or bands are formed at the

ends of the surface to be covered and at intervals of about 1.5 metres across it, and levelled upto

strings stretched at the distance from the masonry. The screeds are usually 15 cm in width and

extend from the top of the wall to the bottom. The screed thus formed form the ground work for

the application of plaster.

Stucco Plastering:- Stucco plaster is mixture of lime, white stone, gypsum and oxides for

colouring. It is an excellent decorative plaster used on both interior and exterior walls.

Blistering:- this the development of local swelling on the finished sueface,due to residue

unslaked lime nodules..

Cracking:- this is the development of one or more fissures in the plaster due to movement in the

back ground or surrounding structure.

Pointing:- the term pointing is applied to the finishing of mortar joints in masonry. It consist of

raking of joints to a depth of 10 to 20 mm and filling it with better quality mortar in desired

shape.

Paints:- is the fluid paste prepared by dissolving a base into a vehicle(carrier) alongwith a

colouring pigment.

Wall paper:- wall paper are widely employed for developing finishing of interior walls. The

wallpaper are made exclusively from paper or combined with other materials. They may be

unprimed, primed, metal coated, embossed etc.

Distempers:- distempers are comparatively cheap decorative paints for walls and ceilings.

Distemper is composed of base, cement, colouring pigments and size. Distemper may be

washable and non- washable types.


Gypsum:- gypsum is a crystalline substance sparingly soluble in water. Gypsum item are good

sound absorbers, incombustible, posses small bulk density and have poor strength in wet state.

Intext questions:

1. Explain in detail the different types of wall tiles available in the market today.

2. What is plastering? Explain in detail the objectives and procedure of plastering.

3. Define pointing and the reasons why it is required.

4. With the help of sketches explain the various types of pointings.

5. Define paint. What is the function of paint?

6. Explain in detail the various constituents of a paint.

7. What are the characteristics of a good paint?

8. What are the general precautions that should be observed during the process of painting?

9. Briefly discuss the history of wallpapers.

10. Explain in detail the various types of wallpapers.

11. Where would you use fabric wall coverings?

12. Visit your local market and find out all possible information with respect to the cost, variety

available, method of production, advantages and disadvantages etc. of the following items:

i. Wall tiles.

ii. Paints

iii. Wallpapers

iv. Fabrics used as wall covering.

Terminal exercise:

Students have to visit local market and find out all possible information with respect to the cost,

variety available, method of production, advantages and disadvantages etc. of the following

items:

Wall tiles.

Paints

Wallpapers

Fabrics used as wall covering.


Assignment /learning activities

Students have to prepare an assignment listing the different types of wallpaper and paint finishes

and compare wall coverings for cost, suitability, maintenance, durability, and the newest trends

in decorating walls. Students need to collect some samples of wall and ceiling coverings to

illustrate and talk about the advantages and disadvantages of the different types of paint and

wallpaper.

Examine new techniques in the application of paint to create a variety of textures and other

visual effects and have to collect different variety of wallpaper samples and compare the

differences in appearance and quality.

Supplementary materials/suggested reading

1. Engineering materials by Surendra Singh

2. Engineering Materials by Rajput

3. Time Savers Standards for Interior Design and Space Planning

4. Building construction by Dr. B.C. Punmia


Unit – II

Floor and Floor Coverings

Lesson -6: Floor Finishes

Lesson -7: Bricks

Lesson -8: Building Tiles

Lesson -9: Stone

Lesson -10: Carpets and Rugs

Lesson -11: Resilient Floor Coverings


Lesson - 6: Floor Finishes

Objective:

To outline the functions of floor covering in an interior.


6.1 Concrete

6.2 Characteristics of good concrete

6.3 Classification of concrete

6.4 Ingredients of plain cement concrete

6.5 Terrazzo

6.0 Introduction

Floor finishes are major design elements in interior spaces. These materials chosen are to be

appropriate for the function of the space as well as aesthetically appropriate. Acoustical

properties of floor finishes have great impact on noise levels, and the colors of the finishes

impact the lightness or darkness in spaces. Extremely light colors, especially white, should be

avoided in high traffic areas due to soiling and possible glare. Floor patterns or changes in floor

finishes may be used to create circulation paths or separation between spaces. Of all finishes,

floors will get the most wear and are usually the most expensive finish material.

There are three basic categories of floor coverings:

• Hard surfaces – concrete, wood, stone, ceramic, and terrazzo

• Resilient surfaces – vinyl composition tile, sheet vinyl, rubber, and linoleum

• Soft surfaces – carpet and area rugs

6.1 Concrete

Concrete is the basic structural material of floors in most new

construction and, when scored, painted, stained, or glazed, can provide

an aesthetically pleasing finish.

Concrete is a mixture of cement (or lime), sand, brick or stone ballast

and water, which when placed in forms and allowed to cure, becomes

hard like stone. The hardening is caused by the chemical reaction

between the cement and water. The cement and water form a paste

which, upon hardening, binds the aggregates to a permanent mass.

Cement is called the "binding material". The stone or brick ballast is

called the "coarse aggregate" as distinguished from the "fine aggregate


"which is sand. The mortar used in concrete is called "matrix". Cement concrete when used by

itself is known as "mass concrete".

Concrete is much stronger in compression than tension. In order to enable it to resist tensile

stresses it is reinforced or strengthened with steel in the form of steel bars or wire netting etc.

The concrete so obtained is called "Reinforced concrete".

6.2 Characteristics of Good Concrete

A good concrete should possess the following characteristics:

1. It should have high compressive strength (so that it can resist the heavy loads of (the

structures). The compressive strength should not be less than 15.5 N/rnrn2.

2. On hardening, it should exhibit minimum shrinkage.

3. It must be adequately dense. The density of a good concrete should be about 24 kN/m3.

4. It should be economical for the desired strength.

5. It should be sufficiently hard and provide enough resistance to abrasion. This property is

of paramount importance when concrete is to be used for making steps of stairs and road

pavements.

6. It must be adequately durable to resist the effects of weathering agencies (e.g., rain, frost

action, variations in temperatures etc.).

7. It should have minimum thermal expansion so as to provide good resistance to fire.

8. It should provide the required finish to the concrete structure.

9. It should have sufficient impermeability or water tightness (so that the water does not

find its access inside the structure)

10. It should have minimum creep (creep, time yield or plastic flow is the continuous strain

which the concrete undergoes due to application of external loads over a period of time.

6.3 Classification of Concrete

The concretes, according to design, are classified as follows:

1. Plain cement concrete

The cement concrete in which no reinforcement is provided is called plain cement concrete or

mass cement concrete. It is considerably stronger in compression but weak in tension or shear.

Uses: It is commonly used in the construction of columns foundation, bed blocks, massive

gravity dams, heavy foundations etc.

2. Reinforced cement concrete (R.C.C.)

It is the cement concrete in which reinforcement is embedded for making tensile, excessive

compressive or shear stresses.

The usual proportions of ingredients are:

1 part Portland cement: 1 to 2 parts clean sand: 2 to 4 parts shingle or crushed stone. The steel

reinforcement used is generally in the form of round bars, 6 mm to 32 mm dia. Expanded metal


or steel fabric in the form of a mesh of steel rods, welded together, are also used as reinforcement

in concrete walls etc.

Uses: It is commonly used for the construction of beams, slabs, lintels, raft or mat foundations

etc.

3. Pre-stressed cement concrete (P.C.C.)

It is the cement concrete in which high compressive stresses are artificially

induced before its actual use. The high compressive stresses are induced by

pre-tensioning the reinforcement before placing the concrete and the

reinforcement is released when final setting of the concrete takes place.

Here, high tensile steel is used as reinforcement. This type of concrete can

take up high tensile and compressive stresses without development of

cracks. By the use of this concrete, the quantity of concrete reinforcement

can be considerably reduced.

Uses: It is used where high stresses develop and it is uneconomical to use

ordinary reinforced cement concrete.

6.4 Ingredients of Plain Cement Concrete

The various ingredients of plain cement concrete are enumerated and discussed below:

1) Cement

Cement is used as a binding material in the concrete required for different engineering works

where strength and durability are of significant importance. For this purpose ordinary Portland

cement is commonly used. However, when work needs to be carried out quickly, rapid hardening

cement is also used.

The cement to be used should be as fresh as possible and should satisfy the latest specifications

of Indian standard Institute.

Functions:

i. It makes the concrete impermeable by filling up the voids existing in the fine aggregate.

ii. It binds the aggregates into a solid mass (due to its setting and hardening properties, when

treated with water).

iii. It imparts strength to the concrete.

2) Sand:

It consists of small angular or rounded grains of silica (SiO2) and is formed by decomposition of

sand stone under the effect of weathering agencies.

It may be either natural sand (e.g., river sand, nalah sand, pit sand and sea sand) or al1ificial sand

(prepared by crushing stones and gravels to powder form). Sand is commonly used as a fine

aggregate in the plain cement concrete.

Sea sand is not recommended for its use for concrete work which is to be exposed to view. It

should be washed with fresh water before use, to remove its salts contents.


Characteristics/ requirements

Fine aggregate should be:

i. Clean, sharp and angular;

ii. Chemically an inert material;

iii. Highly siliceous and free from impurities such as clay, loam, dust, coal particles and

organic matter;

iv. Hard strong and durable.

Functions

i. It fills the voids present in the coarse aggregate.

ii. It assists in hardening of cement by allowing water to penetrate through its voids.

iii. It minimizes shrinking and cracking of concrete.

It prepares concrete economically, of any required strength, by varying its proportions.

3) Coarse aggregate:

It acts as main filler, and forms the main bulk of concrete, around the surfaces of which the

binding materials adhere in the form of a film.

Broken stone, broken brick and gravel are generally used as coarse aggregates. Granite, trap and

basalt give excellent coarse aggregates.

The crushing strength and water tightness of concrete and its resistance to wear and tear depend

upon the aggregates. Further the aggregates balance the shrinkage and volume changes of

concrete.

Characteristics/ requirements

A good coarse aggregate should be:

i. Hard and tough;

ii. Angular or cubical in shape;

iii. Absolutely clean;

iv. Sound, fire resisting and durable;

v. Free from chemicals or coating of clay;

vi. Free from organic matter;

vii. Pass through 75 mm IS sieve and entirely retain on 4.75 mm IS sieve.

Functions

i. It imparts greater volumetric stability and durability to concrete (as compared to the

cement paste alone).

ii. It makes a solid and hard mass of concrete (with cement and sand).

iii. It increases the crushing strength of concrete.


iv. It is cheaper than cement and hence directly helps in achieving economy in concrete

manufacture.

The properties of concrete are greatly influenced by aggregate characteristics given below:

i. Size and grading of aggregate;

ii. Shape and surface texture;

iii. Specific gravity and bulk density;

iv. Strength;

v. Water absorption and surface

vi. Bulking of sand; moisture;

vii. Deleterious substances;

viii. Soundness, durability including alkali-aggregate reactivity

4) Water:

It plays an important role in mixing, laying, compaction, setting and hardening of concrete.

.Water influences the strength development and durability of concrete.

Ordinary drinking water can be used for preparing concrete. It should be free from certain

chemicals injurious to cement.

The quantity of water used should be just sufficient for chemical reaction and suitable

workability of the concrete.

Functions

i. It wets the surface of the aggregates.

ii. It facilitates spreading of cement over the fine aggregate.

iii. It lubricates the surface of the aggregate which influences the workability and

compaction of concrete during plastic stage (leading to the influence on the strength and

durability of concrete).

iv. It chemically combines with various compounds in cement to form a binding medium for

pieces of aggregates.

6.5 Terrazzo

Terrazzo is a flooring material of various sizes of marble chips in cement mortar. Metal divider

strips are used as expansion joints. Terrazzo mixtures are typically installed

two inches thick, but can be installed in thinner settings.

This can be obtained in pre-cast form or laid in situ. Marble pieces mixed in

white or tinted Portland cement, ground and polished, make a most attractive

and rich-looking flooring and walling material; but this has a bad tendency to

crack, with the crack line following the marble insets. Ebony, plastic or brass

strips should be inserted to divide it into smaller areas which allow less

expansion and contraction stresses. It is easy to keep clean and is impervious to

damp, but can be rather noisy.


Lesson - 7: Bricks

Objective:

In this chapter construction material such as bricks, tiles refractory bricks, earthenware and

stoneware will be discussed. All these materials are made from clay and are also know as

clay products.


7.2 Comparison of stone and brick

7.3 Constituents of brick Earth

7.4 Function of Constituents of Brick Earth

7.5 Harmful Ingredients in Brick Earth

7.6 Requirements of Good Brick Earth

7.7 Manufacture of Bricks

7.8 Classification of Bricks

7.1 Introduction

The brick is the most commonly used building material, though tiles, refractory bricks, earthen

wares and stone wares serve different construction purposes. The bricks are being commonly

used for constructing walls, columns, roofs, paving floors and as coarse aggregate for concrete

work in foundations, under-floors, etc.

The bricks do not require dressing and the art of laying bricks is so simple that the bricks work

can be carried out with the help of unskilled labourers. Thus, at places where stones are not

easily available, but if there is plenty of clay suitable for the manufacture of bricks, the bricks

replace stones.

7.2 Comparison of stone and brick

Comparison of stone and brick is given in the following table:

S.No. Stone Brick

1. It is heavier than brick It is lighter than stone

2. It is obtained from rocks. Made from clay

3. Free form clay holes and flaws Free from lumps, flaws and cracks

4. Hard and tough Hard and sound

5. It absorbs heat more than a brick It absorbs less heat comparatively

6. Water absorption less than 5% Water absorption less than 16%

7. It is uniform in colour and can be

shaped to the desired size.

Uniform in colour, shape and size


8. It has high durability which

depends upon its chemical

composition and its physical

structure.

Its durability is less than that of stone.

9. Particularly suitable for

construction work in industrial area

as it is acid and smoke proof.

Acid and smoke resistance is good but

less than that of stone

10. Quarrying dressing and

transportation costly.

Overall cost of manufacture less than

Stone

11. Labour cost for laying is high. Easily laid to form walls of required

uniform thickness, labour cost for brick

masonry much less.

7.3 Constituents of brick Earth

Brick earth is derived by the disintegration of igneous rocks. Potash felspars, orthoclase or

microcline mainly responsible for yielding clay minerals in the earth. This mineral decomposes

to yield kaolinite a silicate of alumina which on hydration gives a clay deposit AL2O3.2H2O

known as kaolin.

A good brick earth should be such that can be easily moulded and dried without cracking and

wraping.

7.4 Function of Constituents of Brick Earth

Functions of various constituents/ingredients of brick earth are described below:

1. Alumina or clay

It is the principal constituent of every kind of brick earth.

It provides plasticity to the earth and makes the brick hard.

If not mixed with sand shrinkage and warping results.

2. Silica or sand

It exists in brick earth either in chemical combination with alumina as silicate of

alumina or mechanically mixed with caly as sand.

If silica in suitable proportion is added to clay it imparts hardness to the brick and

checks it shrinkage, cracking and warping on drying. But if added in greater

proportions makes the brick brittle.

Addition of silica also increases hardness, durability and resistance to heat.

3. Lime

It helps silica to melt at lower temperature and binds the particles of the bricks

together

It also reduces shrinkage of bricks.


It should be present in finely divided state otherwise the lumps on burning will

change to quick lime and disintegrate the brick on absorbing moisture.

4. Iron Oxide

A small quantity of iron oxide present in brick earth, acts as a flux, helps grains of

sand to melt and binds the particles of clay together.

It imparts pleasing red colour to the brick. Its excess percentage (8 to 11) makes the

brick dark blue.

5. Magnesia

Small quantities of magnesia in brick earth make the bricks of yellowish colour and

reduce shrinkage. But excess of magnesia leads to the decay of bricks.

6. Manganese

Manganese in small proportions along with iron makes the brick darker (or even

black)

7.5 Harmful Ingredients in Brick Earth

Limestone and kankar nodules: The presence of limestone and kankar nodules in the brick earth

is harmful and corps up serious troubles. In heating limestone is converted into lime which on

contact with water swells and cases the brick to split and crumble to pieces. But however, a

certain quantity of limestone is desirable in brick earth as it binds the particles of brick together

and reduces shrinkage on drying. It is essential that limestone must be present in a finely divided

state and not in lumps.

1. Alkalise: If alkalise are present in the brick earth, they lower the fusion point of clays and

cause the brick to fuse, twist and warp during burning. Alkaline salts if present in

finished bricks absorb moisture from the atmosphere and create damp conditions which

are detrimental to health. Further when the moisture dries up a greyish white deposit is

left behind which spoils the appearance of the structure, the effect being known as

efflorescence.

2. Pebbles of stone and gravel: They do not exercise any harmful effect chemically, but do

not permit the caly to be thoroughly mixed and thus impair the uniformity of a brick.

3. Iron pyrites: Iron pyrites, if present in the earth decompose and oxidize in the brick and

cause the brick to split.

4. Kallar or reh: It consists of sulphate of soda mixed with common salt and carbonate of

soda. These salts prevent the bricks from being properly baked. Its presence in the earth

has the effect as that of alkalise.

5. Vegetation and organic matter: The presence of vegetation and organic matter in brick

assists in burning. But if such matter is not completely burnt, the bricks become porous

(this is due to the fact that the gases will be evolved during the burning of the

carbonaceous matter and it will result in the formation of small pores).


7.6 Requirements of Good Brick Earth

A good brick earth should fulfil the following requirements.

1. It must have proper proportions of sand, silt and clay.

2. It must be homogeneous.

3. It should have sufficient plasticity (so that the bricks can be properly and conveniently

moulded with sharp and well defined edges).

4. It must be free from lumps of lime or nodules of kankar.

5. It must be free from earth containing alkaline salts, kankar or reh etc.

6. It must be free from pebbles, grits and lumps of earth.

7. It must not contain vegetable and organic matter.

8. It should not be mixed with salty water.

7.7 Manufacture of Bricks

The manufacture of bricks involve the following steps:

1. Preparation of clay

2. Moulding of bricks

3. Drying of bricks

4. Burning of bricks.

Preparation of Clay

(i) Selection of site and unsoiling:

The site selected for the manufacture of bricks must have suitable soil available in

sufficient quantity; otherwise unnecessary labour and cost of digging and transportation

of the soil would be involved.

Generally, for making soil suitable for brick making, certain materials are required to be

mixed with the soil. Therefore, the availability of such materials near the site of brick-

making is amply important.

It is also necessary that water fuel like coal and wood are easily available in adequate

quantities.

The site should be selected after giving due consideration to suitability of soil and

location of the water table. Site should be so selected that the water table during breaking

session is at least I meter below the floor of the kiln.

After selecting the site, the top layer of soil, about 200 mm in depth is taken out and

thrown away. They clay in top soil is full of impurities, (e.g. Roots of grass, vegetation

etc), and hence it is to be rejected for the purpose of preparing bricks.


(ii) Digging and cleaning: The soil below 200 mm is dug out preferably before rains. It is then

cleaned off stones, pebbles, vegetable matter etc. All the lumps of soil should be broken into

powder form.

(iii) Weathering and blending: The earth is then spread out to a depth of 600 to 1200 mm and

left to the atmospheric action; this process being known as weathering. It extends from a few

weeks to some months and imparts plasticity and strength to the clay. IT is this stage during

which different types of earths such as sandy or calcarious clays could be mixed in suitable

proportions with little quantities of coke, ash, etc., to develop the essential qualities needed

for moulding, drying and burning of bricks. The whole mass is mixed uniformly and

proportionate quantity of water is added. The earth is covered up with cloth or mats. This

process of mixing ingredients is called blending.

(iv) Tempering: Tempering process consists is kneading the earth under feet of men or cattle to

make it stiff and plastic. Addition of water is made from time to time and tempering is

continued till homogenous mass of earth is obtained. A soft plastic clay could be prepared by

about 25 to 30 percent of water. This method is adopted for the majority of common hand

made bricks but in case of superior bricks needed on large scale tempering is carried out with

help of a pug mill.

Moulding of Bricks

After the earth or clay is prepared the moulding of the bricks is carried out either by hand or by

machine.

Hand moulding: Hand moulding usually adopted in India is of the following two types:

i. Ground moulding: The process of

moulding bricks on the ground by manual

labour is known as ground moulding and it

is carried out as follows:

The moulder places his mould (wooden or

steel box as shown in Fig 3.2a, b) flat in one

corner of the ground which is already

levelled, plastered and sprinkled with sand.

He then lifts a lumps of prepared clay over

his head with both hands, dashes it into the

mould and forces it with hands in order to

fill the corners of the mould. He then strikes

of the superfluous clay above the level of

the mould with a piece of wood or iron

called a strike (fig3.4) or a wire on a bow

and throws the cut off clay on the ground to

be mixed again with earth to be prepared.

The mould is then lifted off leaving the

brick on the ground and again placed by the side of the brick thus made. A second brick

is moulded then and so on. The moulder moulds bricks lying flat in rows till the whole

ground is covered. Each moulder can mould about 600 to 1000 bricks on an average per

day.


In this process bricks are made directly on the ground and so their lower faces are very

rough and moreover they can have no frog.

Comparatively better type of ground-moulded bricks could be prepared by using two pallet

boards of thin wooden pieces, one at the base of the mould and other on top of it. After the brick

is moulded it is carried between the pallet boards and placed on its longer side face. Leaving the

brick there for drying the pallets are brought back for further moulding.

Frog or impression

It is an indentation mark left on the face of a brick during moulding process. It serves the

following two purposes:

a) It indicates the name of the person or the firm who manufactures the bricks.

b) It provides a key for mortar for developing a structure grip when used.

Frog in the brick is formed by providing a projection or fillet on the corresponding face of mould

(usually of the lower pallet board)

(ii) Table moulding: The process of moulding bricks on a table by manual labour is known as

table moulding and it is carried out as follows:

The moulder stands behind the table and places his mould either on the table itself, in

which case the bottom of the brick is flat or generally on a board fixed on the table called

stock board of the same size as the inside measurement of the mould and carrying

projection for the frog. The mould in the last case is to be made deeper than the thickness

of the brick by 37.5 mm which is the thickness of the stock board.

The mould is placed to fit the stock board, filled up with earth, superfluous earth removed

(as described above) a thin pallet board is placed on the mould, and then mould, pallet

board and brick are lifted together smartly off the stock board inverting it as he does so.

Then he (moulder) places the whole on the page (fig 3.4) on his left side with pallet board

downwards and lifts up the mould leaving the brick on the pallet board. A boy places

another pallet board on the brick and carries it away between two boards to the drying

ground, where it is placed on its edge. Pallet boards are removed.

The second brick moulded is placed next to the first and this is repeated until the whole

space is covered.

Machine Moulding

This brick making method proves quite useful when a large number of bricks have to be

manufactured quickly.

Machine moulding can be performed by the following two methods.

i. Plastic method: The clay in plastic condition is formed through an opening of dimensions

equal to the length and the breadth of the bricks in a rectangular plastic band from which

the bricks of required thickness are cut with wires or knives fixed in a frame. This is

quick press of manufacturing bricks. It proves economical when bricks are required on a

large scale.


ii. Dry process method: Superior bricks which are to withstand heavy pressure are made by

compressing under great pressure moist powdered clay into well shaped bricks called

pressed bricks. The bricks made by this method are dense, smooth and more uniform in

the shape. The bricks produced by this method are much stronger than ordinary bricks

and do not necessitate drying and can be directly fed into the kiln for burning.

Due to heavy initial cost of machine moulding method, it is not presently popular in our country.

Drying of Bricks

After the bricks are moulded, they are dried by the following two methods:

(i) Natural drying: It is also called hack

drying and consists in arranging the wet

bricks in rows on their edges on a

slightly raised ground called hacks.

Little space for circulation of air is kept

for each brick. It should be ensured that

no sudden drying is caused by direct

exposure to sun and wind and a

portable cover is provided to protect the

bricks from rain. In certain places

where temperature variations are too

much temporary sheds are erected for drying purpose. The air and sun dried

bricks are adequately strong and durable and produce good results when

employed for construction of simple structure.

(ii) Artificial drying. This method is used when bricks are required on a large scale

and at a rapid rate. The heating of the bricks is carried out in special driers such as

tunnels or chambers which receive heat from special furnaces built for the

purpose, hot flue gases form the cooling chambers of a kiln and waste steam from

the engines of driving machinery.

Burning of Bricks

Bricks after being moulded and dried are burnt in the kilns. The purpose of burning is two fold:

i. To impart hardness and strength to the bricks;

ii. To increase the density of the bricks so that they will absorb less quantity of water.

Types of kilns: The bricks may be burnt in anyone of the following kilns :

Clamp or open kiln:

It is also known as Pazawah.

It is suitable for burning only ordinary bricks, i.e. ground moulded bricks of inferior type.

This method of burning is usually adopted in rural areas where transport charges of bricks

from urban areas are high. Furthermore as the number of bricks required for construction

of ordinary building is small, it is not felt necessary to set up bigger kilns which entail a

huge expenditure.


The size of the clamp depends upon the number of bricks to be burnt. For one lakh bricks

its size should be 15m (length) x 13 m (breadth) x 5 m (height)

These clamps are sometimes also made trapezoidal in form. A slight slope of 15 degrees

is usually given to the ground length wise.

In a brick clamp, fuel and bricks are laid in alternate layers as shown in Fig. 3.6. On the

sides and on top of the clamp, a coating of earth provides some protection. The air dried

bricks are arranged in a criss-cross pattern on their edges with a gap of about 5 cm

between them to ensure proper circulation and upward draught of the hot gases from

below. After the kiln is started it takes two to six months for burning and cooling the

bricks. This clamp is a temporary structure for burning and is built again for the next

burning of raw bricks.

Advantages:

i. Burning of bricks is cheap and economical.

ii. Considerable saving of fuel.

iii. Bricks produced are tough and strong (since the burning and cooling of bricks is gradual).

iv. Skilled labour and supervision are not required for the construction and making of the

clamps.

v. The clamp is not liable to injury from high wind or rain.

Disadvantages:

i. Very slow process.

ii. The quality of bricks is not uniform.

iii. The bricks are not of regular shape (due to the settlement of bricks when fuel near bottom

is burnt and turned to ashes).

iv. The bricks are liable to burn unevenly (since it is not possible to regulate the fire).

Intermittent kilns (overground kilns):

These kilns are permanent one as opposed to clamps which are temporary structures, and can be

put to use again for burning the bricks. Here the burning is not continuous. These are made

rectangular or circular in shape and may be of 'upward draught' or 'down draught' type.

Qualities of Good Bricks

The good bricks which are to be used for the construction of important engineering structures

should possess the following qualities/characteristics:


1. Size and shape: A good brick should be uniform in size (standard) and should have

rectangular plane surfaces with parallel sides and sharp straight right-angled edges. Its

surface should not be too smooth or, otherwise, the mortar will not stick to it. Figure 3.9

shows details of a standard brick. According to ISI specification, size of the brick should be

190 mm X 90 mm x 90 mm and the depth of the frog should be between 10 to 20 mm.

Length and width of frog [Fig. 3.9(b)] should be 100 mm and 40 mm respectively. Thickness

of mortar should be 5 mm on each surface of each brick. So the dimensions of the each brick

including mortar joint will be 200 mm x 100 mm x 100 mm. A standard brick weighs nearly

30 N.

2. Colour: The bricks should be table-moulded, well burnt in kilns, copper coloured, free from

cracks and with sharp and square edges. The colour should be uniform and bright.

3. Structure: A good brick should show fine, compact and uniform structure in broken form.

4. Soundness: A good brick should give a clear metallic ringing sound when struck with

another brick.

5. Hardness: A good brick should be so hard that finger nails should not be able to make any

impression on its surface when scratched.

6. Porosity: A good brick should not absorb more than 20 per cent of its dry weight of water

when kept immersed for 24 hours.

7. Strength: A good brick should have minimum crushing strength of 10.5 N/mm2. Ordinarily

it should not break when dropped flat on hard ground from a height of about 1 m.

8. Resistance to fire: A good brick should have adequate resistance to fire. Ordinary bricks can

resist temperature upto 1200 °C. Bricks to be used for lining of furnaces, etc., should be of

special quality (known as fire bricks).

9. Efflorescence: A good brick should not contain much alkaline salts, which may cause

efflorescence on its surface and decay the brick.

10. Durability: A good brick should be able to resist the effects of weathering agencies like

temperature variations, rain, frost action, etc.


7.8 Classification of Bricks

Conventionally, the bricks are classified in the following two types:

1. Sun dried or katcha bricks:

These bricks are dried with the help of heat received from the Sun after the

process of moulding. These bricks are not burnt in camp or kiln.

These bricks can only be used in the construction of temporary and cheap

structures.

Such bricks should not be used at places exposed to heavy rains.

2. Burnt or pacca bricks:

The bricks which are burnt in a clamp or kiln after moulding and drying are called

burnt or pacca bricks.

These bricks are hard, strong and durable and are generally used in permanent

works. These bricks are further classified into the following four types:

a) First class bricks: these bricks are table-moulded and they are burnt in kilns.

Characteristics: The following are the characteristics of a first class brick:

i. A first class brick is well burnt and regular in shape.

ii. Edges are sharp and well defined.

iii. It is sufficiently hard and sound.

iv. Its surface is smooth, clean and free from cracks.

v. A fractured surface shows a uniform compact structure (free from lumps or grits and

holes).

vi. Water absorption shall not be more than one sixth of its weight of water when kept

immersed for sixteen hours.

vii. When two bricks are struck against each other, a metallic ringing sound is produced.

viii. When soaked in water for 24 hours and dried in shade does not show efflorescence.

ix. It should not break when dropped from a height of 1 to 2 meters.

x. It has specific gravity of 1.8.

xi. It is so hard that no mark can be produced on it with finger nails.

xii. It has a minimum crushing strength of 10.5 N/mm2.

Uses: For flooring and walling purposes. As ballast for R.C. work. Shaped bricks are used in

carvings, arches and copings.

b) Second class bricks: There bricks are ground moulded and they are burnt in kilns.


Characteristics:

i. A second-class brick is well-burnt but irregular in shape and size.

ii. It has a rough surface.

iii. Its edges are neither straight nor well defined.

iv. It is not free from lumps and cracks.

v. It does not have a uniform colour.

vi. It has fine, compact and uniform texture.

vii. It shall produce a ringing sound when struck with one another.

viii. It shall have a minimum crushing strength of 7 N/mm2.

Uses: Such types of bricks are used in unimportant situation and for internal walls (where the

bricks are generally hidden from view.

c) Third class bricks: The bricks which are under burnt and are not uniform in shape and size

are called third class or pilla bricks. These bricks are ground-moulded and then are burnt in

clamps.

Characteristics:

i. A third class brick has a light yellowish colour.

ii. It is not well-burnt.

iii. It is soft,

iv. When two bricks are struck a dull sound is emitted

v. It is associated with flaws and cracks.

vi. Its edges are irregular and surface quite rough.

Uses: Third class bricks are used in inferior and temporary building.

d) Over burnt or jhama bricks: These are over burnt bricks with irregular shape and dark

colour.

Characteristics:

i. They are overburnt, vitrified and distorted bricks.

ii. They are irregular in shape and size and are available in the form of lumps.

iii. They are dark in lumps.

iv. They are strong and hard.

v. They produce metallic ringing sound.

Uses: these bricks are used as aggregates for making concrete to be used in foundations, floors,

etc. and as road metal.


Lesson - 8: Building Tiles

Objectives:

To study hard flooring finishes in various building and rooms.


8.2 Characteristics of a good tile

8.3 Types of Tiles

8.4 Earthenware and Stoneware

8.5 Glazing

8.5.1 Transparent Glazing

8.5.2 Opaque Glazing or Ship Glazing

8.1 Introduction

Tiles are thin slabs of brick earth, burnt in a kiln. These are thinner than bricks and have a greater

tendency to crack and warp in drying and burning than ordinary bricks and are more liable to

breakage. Therefore, a greater care should be taken in their manufacture. They should be dried in

shade, burnt and cooled gradually in specially made kilns.

8.2 Characteristics of a good tile:

A good tile should possess the following characteristics:

i. It should possess uniform colour.

ii. It should be properly burnt.

iii. It should be free from cracks, flaws and bends.

iv. It should be hard and durable.

v. It should have proper shape and size.

vi. When placed in position, it should fit well.

vii. Its broken surface should exhibit even and compact structure.

viii. It should give a clear ringing sound when struck with light hammer or with another tile.


8.3 Types of Tiles

The tiles, according to their use, are divided into the following five types:

1. Roofing tiles: These tiles should be strong,

durable and perfectly leak proof. Alth The

tiles, according to their use, ough expensive

in first cost, they need less maintenance

cost.

Roofing tiles may be common tiles, encaustic

tiles, manglore tiles and country tiles. The

commonly used roofing tiles are described

below:

a) Flat tiles: These tiles are rectangular

in shape and are of various dimensions. They are laid in cement or lime mortar. The

different types of flat tiles are discussed below:

1. Slate tiles: The sizes available are: 60 cm x 30 cm x 15 mm and 50 cm x 25 cm x 10 mm.

These tiles should be reasonably straight, of uniform colour, texture, free from veins,

cracks, fissures, white patches etc. The water absorption after 24 hours immersion in cold

water should be maximum 21 per cent by weight.

2. Burnt clay flat terracing tiles: These tiles should be uniform in shape, size and be tree

from irregularities, (e.g. bends, twists, cracks etc.). The water absorption should not

exceed 20 percent by weight. The compressive strength should not be less than 7.5

N/mm2.

a) Pot tiles or country tiles: These tiles are also

sometimes called pan tiles. They are hand

moulded, first into a flat tile, then to the required

shape on wooden pattern and burnt in a kiln after

drying. These tiles are semi-circular in section

(refer Fig 3.14). These are used either alone or

with flat tiles. These tiles are less liable to be

displaced by the birds. These tiles are laid on

sloped roofs along with the concave side up and

longer end towards the ridge. Then another row

of same tiles with convex side up and small end

towards the ridge is laid covering the adjoining

edges of every pair of tiles below. These tiles are

extensively used in the rural areas.

b) Allahabad tiles: These tiles are of different

shapes. They are generally laid side by side and

joints are then covered with half round tile. They

should not absorb water more than 20 per cent by

weight. They are used for making good and

pleasing roofs.


c) Corrugated tiles: These tiles have corrugations and when they are placed in position, a

side lap of one or two corrugations is formed. .The placing of such tiles on a roof gives an

appearance of corrugated galvanized iron sheets. They are very good in appearance, but

can be easily blown away by a violent wind.

d) Manglore tile: These tiles are red in colour and

made of double chanelled Basel Mission Manglore

pattern. They are of flat pattern and are provided

with suitable projections so that they interlock with

each other, when placed in position. The life of

these tiles is about 25 years with replacement of

about 5 per cent per year.

e) Ridge, valley and lip tiles: These tiles are made

from good earth, and are specially shaped.

f) Encaustic tiles: These tiles are used for decorative

purpose and consist of three layers:

i. The face is a thin coat of pure clay of the colour

required.

ii. The body is of coarse clay; and

iii. The back is formed with a thin layer of clay

different from the body, as it is to prevent warping.

1. Flooring tiles: These tiles are flat and usually

square or rectangular in shape. These can be made

in any colour and of any geometrical shape. They

should give a ringing sound when struck with

each other. They should not absorb water more

than 24 per cent by their weight. The fractured

surface of the tile should be clean, dense and

sharp at the edges. .They should show maximum

resistance to impact. Common sizes of flooring

tiles are: 15 cm (length) x 15 cm (width) x 18 mm

(thickness); 20 cm x 20 cm x 20 mm; 22.5 cm x

22.5 cm x 22 mm.


2. Wall tiles: These are similar to the floor tiles except for their

design and degree of burning. They are burnt comparatively at a

low temperature, glazed and burnt again at a still lower

temperature. They can be made in different designs and colours

and be built to any size.

Uses: These are used on face work; to some extent on arches and

for architectural ceilings, etc.

3. Drain tiles: These tiles are usually long curved sections of

various shapes and sizes such as semi-circular, a segment of a

circle or circular.

Uses: They are generally used for draining wastewater. If they

are to be employed for carrying sewage, glazed tiles should be

used.

4. Glazed earthenware tiles: These tiles are of earthenware.

having top surface glazed and underside unglazed so that tile

may adhere properly to the base. These tiles are made in two

sizes: 149 mm x 149 mm and 99 mm x 99 mm, having

thicknesses 5 mm, 6 mm and 7 mm. The joint thickness is 1mm.

They should not absorb more than 18 percent of water.

Uses: These tiles and associated fittings are generally used for

finishing the surfaces of wails and floors of water closets,

bathrooms, kitchens, hospitals etc, (where cleanliness is

important).

8.4 Earthenware and Stoneware

Earthenware

The clay product which is manufactured from ordinary clay mixed with sand, crushed

pottery. etc., by burning at low temperature is known as earthenware.

The earthenwares are generally soft and porous. They are liable to damage by

atmospheric action.

They should not absorb water more than 18% by weight.

When glazed, the earthenwares become impervious to the water and they are not affected

by acids or atmospheric agencies.

Uses: Earthenwares are used for making ordinary drain pipes, partition blocks and electrical

cable conduits. Glazed earthenware tiles are used in finishing floors and walls of kitchens,

bathrooms, water closets, hospitals, etc, where cleanliness is an

important criterion.

Terra-cotta

Terra cotta is a kind of high quality earthenware which is used as a

substitute for stone for ornamentation of buildings.


Manufacture:

It is made from a finely ground mixture of refractory brick clay and shale or refractory

clay and impure clay which is mixed with ground brick or other burnt clay product to

reduce shrinkage.

It is then ground to a fine powder, put into a large water tub and thoroughly mixed with a

spade. Water is then run off from the tub.

This clay is thoroughly pugged when dry enough to make it fit for moulding.

Moulding is done by pressing the clay carefully in moulds in a manner similar to brick

moulding.

After being moulded the terra-cotta pieces are slowly dried to avoid warping and burnt

(in special kilns without coming in contact with fire) with utmost case to prevent

distortion or discolouration by flames and gases. The maximum temperatures attained are

1100 °C to 1200 °C.

Porous terra-cotta is made by mixing sawdust in the clay.

Advantages:

i. Can be cleaned easily.

ii. Light in weight.

iii. Strong and durable material.

iv. Available in several colours.

v. Can be moulded into desired shapes easily.

vi. Being fireproof, it can be used with R.C.C work conveniently.

vii. Not affected by acids and atmospheric agencies

viii. Cheaper than ordinary finely dressed stones.

Uses: Used for all sorts of ornamental work, and as building material in the form of shaped

blocks.

Porcelain

The term porcelain is used to indicate fine earthenware

which is white, thin and semi-transparent; it is sometimes

referred to as whiteware.

It is prepared from clay, felspar, quartz and minerals. The

constituents are finely grounded and then are thoroughly

mixed in liquid state. The mixture is given the desired shape

and is burnt at high temperature.

The various types of porcelains available are used for various

uses such as sanitary-wares, electric insulators, crucibles,

reactor chambers, etc.


Low voltage porcelain is prepared by dry process and is mainly used for lamp sockets,

switch blocks, etc. High voltage porcelain is prepared by wet process.

Stoneware

It is the clay product which is manufactured from refractory

clay mixed with crushed pottery, powdered stone, etc, by

burning at a high temperature.

The clay is prepared carefully and moulding is done

accurately to the required shape. It is then dried and the

material burnt in a kiln, raising the heat gradually to a high

temperature and maintaining this for one to three days

depending upon the size of kiln and the articles in it. The burnt

stoneware is allowed to cool down gradually.

It is impervious to moisture, hard, closed grained and durable

The stoneware is more compact and dense than earthenware.

The stonewares can be kept clean easily.

When glazed, the stonewares become impervious to the water and they are not affected

by acids or atmospheric agencies.

Uses: These are employed for drain and sewer pipes, sanitary wares and vessels or jars to hold

chemicals, etc.

8.5 Glazing

It is the process of forming some transparent film over the surfaces of bricks, tiles,

earthenware or stoneware to improve upon their appearance and also to protect them

from the action of weather, sewage, chemicals or other destroying agents.

A glaze is a glassy coat of thickness about 0.1 to 0.2 mm applied on the surface of an

item and then fused into place by burning at high temperature.

Glazing should be such that it does not craze (formation of fine cracks on the surface of

clay) when the article is exposed to any change of temperature.

Glazing may be transparent like glass or opaque like enamels. For obtaining coloured

glazes, the oxides and salts of various metals or special refractory colouring agents are

added.

8.5.1 Transparent Glazing

Transparent glazing is of two types

i. Salt glazing: In this method, common salt (sodium chloride) is thrown into the kiln,

containing the articles to be glazed at the close of the burning operation when the

temperature reaches to about 1300 degrees. The salt vaporizes and attaches itself

chemically to all exposed surfaces of the clay products, thus forming a thin layer of

transparent gloss over the surface. The quantity of salt and throwing at proper time


should be done with extreme care. This method is useful for sanitary pipes and chemical

stoneware.

ii. Lead glazing: lead glazing is preferred to salt glazing for getting articles of better quality.

In this method, hot article to be glazed is dipped in a bath containing oxide of lead and tin

when particles of these materials adhere to the article dipped. The article is then

withdrawn and reburnt when high temperature of the finance melts it forming a film of

glass over the exposed surface.

In this method of glazing, the glaze does not penetrate into the body of the ware and as a

matter of fact, it can be easily detached from the surface of the ware.

Uses: This method is used for terra-cotta, earthen wares and fire-clay wares.

8.5.2 Opaque Glazing or Ship Glazing

The glazing materials consist of quartz, felspar, boric oxides, oxide of tin, zinc, lead,

china clay etc. A mixture of these materials is prepared and ground to fine paste (known

as slip) in the presence of water.

The clay product to be glazed is first dried and dipped into the slip and then fired into the

furnace at a temperature of about 120 degrees. During the process of firing the

composition of the glaze gets completely vitrified and forms a uniform layer over the

surface of the burnt clay product.

In this glazing process, burning and glazing of the clay products are simultaneously

achieved.

Uses: Opaque glazing is used where it is desired to give the whole or any part of the article a

better appearance than that presented by the burnt material. Basins, dishes, cups, etc., are opaque

glazed.


Lesson - 9: Stone

Objective:

To study about different stones.


9.2 Classification of Rocks

9.3 Characteristics of Good Building Stones

9.4 Properties of Some Common Building Stones

9.1 Introduction

Stone floors include slate, granite, marble, limestone, and travertine among others. Stone is

available in a variety of colors and finished in polish this requires high maintenance, has poor

slip resistance, and should not be used in heavy traffic areas, especially adjacent to building

entrances.

All stone may be used in interior or exterior applications; however, some stone, such as slate,

requires applied sealants when used indoors. Granites are very durable surfaces that can be used

in most applications. Marbles range from hard to soft and are classified as such. Marbles usually

require the most maintenance.

The stones are derived from rocks which form the earth's crust and have no definite shape or

chemical composition but are mixtures of two or more minerals.

The mineral is a substance which is formed by the natural inorganic process and possesses a

definite chemical composition and molecular structure.

Following are some important uses of stones in Interior Designing:

1. Flooring material for residential and public buildings.

2. Construction of residential and public buildings.

3. Facework of structures where massive appearance, solidity of construction and

ornamental features are the primary requirements.

4. Used as aggregate for concrete.

5. Used in the form of veneers for decorative front and interior of buildings.

9.2 Classification of Rocks

The rocks from which stones are obtained are classified in the following four ways:

a) Geological classification:


Geologically the rocks are classified into three different types:

1. Igneous Rocks: The cooling of molten lava on or inside the earth‟s surface during the

volcanic eruption forms igneous rocks. The portion of lava, which comes outside the

surface, cools quickly and forms the rock of non-crystalline nature cal1ed as Trap or

Basalt. The rest of the portion which remains inside the earth undergoes cooling at a slow

rate and results in formation of rock of crystal1ine variety known as Granite.

2. Sedimentary rocks: Sedimentary rocks are formed by gradual deposition of disintegrated

rocks (due to the atmospheric action such as rain, wind and temperature), vegetable

matter and clay at the bottom of rivers, lakes or sea. These are also called stratified

because these rocks are formed in layers. Lime stone and sand stone belong to this

category of rocks.

3. Metamorphic Rock: When sedimentary or even igneous rocks are subjected to great heat

and pressure inside the earth, a new variety of rock is formed which is known as

metamorphic rock. This change of structure is cal1ed metamorphism. For example,

limestone changes to marble, slate changes to gneiss, etc.

http://images.google.co.in/imgres?imgurl=http://www.lakewoodconferences.com/direct/dbimage/50250233/Granite_Tile.jpg&imgrefurl=http://www.lakewoodconferences.com/catalog/13/16/676/granite.html&h=360&w=360&sz=33&hl=en&start=8&tbnid=hoUOu8mLMwZzsM:&tbnh=121&tbnw=121&prev=/images?q=granite&gbv=2&hl=en&sa=X


b) Physical classification:

The basis of this classification are physical properties of rocks, the manner and arrangement

of different particles and mass forming a stone. Physically the rocks are classified as:

1. Stratified Rocks: are those which exhibit distinct layers which can be separated. The

plane along which the separation of the layers can be carried out is called cleavage plane.

Lime stone, slate and sandstone are the examples of this kind of rock.

2. Unstratified rocks: these do not show any sign of strata and cannot be easily split into

slabs. Examples are granite, trap, marble, etc.

c) Chemical classification:

The chemical constituents of the rocks are the basis of this classification. Chemically the

rocks are classified as:

1. Siliceous: In case of siliceous rocks silica is the main constituent. The silica in free state

is called sand and in combined state silicate. The rocks containing silica in free form are

harder, while those having silica in combined forms are likely to be disintegrated. Sand

stone and quartzite are examples of siliceous rocks.

2. Argillaceous: In Argillaceous rocks clay or alumina is the main constituent. Slate,

laterite, kaolin, etc., belong to this category.

3. Calcareous: these rocks have calcium carbonate or lime as their leading constituent.

These rocks are readily acted upon by even dilute hydrochloric acid. Limestone and all

the marbles are some of the important examples.

d) Practical classification:

Practical classification is based on the usage. Practically stones have been classed as:

Granites, basalts. Laterites, marbles. limestones, sandstones, slates.

9.3 Characteristics of Good Building Stones

Stones find their applications in the construction of heavy structures such as dams, docks and

harbours, weirs, bridge piers, buildings, etc. To find the suitability of stones under different

conditions, the following characteristics should be considered:

1. Appearance and colour: The stones which are to be employed for decoration work

should have uniform and appealing colour and should be free from flaws and clay holes.

The use of stones containing too much iron should be discouraged as the formation of

iron oxide disfigures them and brings about disintegration. The stones should also have

the ability to receive good polish.

2. Weight: The specific gravity hence the weight of the good building stone should be high

as heavier stones can resist the force of bigger magnitude. A heavy stone possesses more

compactness and less porosity.

3. Porosity and absorption: Porosity (which is decided by the number of pores) exists in all

the stones but if it is present in greater extent it makes the stone unsuitable for building

construction because during rain, water seeping into pores contains acids and fumes


(absorbed from atmosphere) which destroy the stone. When the climate is cold, water

entering the pores may even freeze and split the stone.

4. Fineness of grain: The stones which are fine grained are suitable for moulding works. If

the stones are non-crystalline they are likely to disintegrate under the action of natural

agencies.

5. Compactness: Stone's durability is decided by their compactness or density of

composition. A compact stone can withstand the effects of external agencies effectively.

6. Resistance to fire: For resistance against fire, the stone should have homogeneous

composition and should also be free from calcium carbonate or oxide of iron.

7. Electrical resistance: The electrical resistance of a stone decreases when it gets wet.

Thus to have steady and high electrical resistance, the stone must be non-absorbent like

slate.

8. Strength: Stones used in the structures are usually subjected to compression; so they

should have sufficient strength to cope with the requirements. Generally all the stones

possess a reasonable degree of strength as far as their use in building work is concerned,

but for heavy structures only those stones are suitable which have high strength

comparatively.

9. Durability: A stone is more durable in case it is compact, homogeneous and free from

any material affected by dilute hydrochloric and sulphuric acids. It should also have

negligible water absorption.

10. Dressing: The art of shaping a stone is known as dressing. Stones should possess uniform

texture and softness so that they may be easily dressed; if it is too hard, finish will be

poor and dressing uneconomical.

11. Cost: The cost is an important consideration in the selection of building stone. Other

things being equal the cost of a stone depends upon the ease with which it can be quarried

out, the proximity of the quarry to the place of use, and the transportation facilities

available. The subsequent cost of dressing a stone, before it is placed directly in the

structure, should also be low.

12. Seasoning: Good stone must also be free from quarry sap. To ensure this, the stones after

quarrying and dressing should be left for a period of 6 to 12 months for proper seasoning,

before using in construction work.

9.4 Properties of Some Common Building Stones

1. Granite: it is an igneous rock, and its main constituents are quartz, felspar and mica.

Characteristics:

i. Its specific gravity is 2.64 and absorption less than 1 %.

ii. It has a mottled appearance.

iii. Significantly strong and durable.

iv. Finely grained granite and takes a fine polish

v. Crushing strength varies from 110 to 140 MN/m2.


vi. It has least fire resistance as it cracks under a strong fire.

vii. Its colour depends upon that of felspar.

Uses:

i. Fine grained granite is suitable for ornamental columns, plinth, etc., as it takes good

polish.

ii. Owing to the hardness, weight and durability of granite it is considered most suitable for

the construction of sea walls, light houses, bridge piers, etc.

iii. Large pieces are used as building blocks, the smaller as road metals or railway ballast and

the chippings for the manufacture of concrete or artificial stone.

iv. Occurrence: Jhansi (U.P), Jabalpur (M.P.), Ajmer (Rajasthan), Dalhousie and Kangra

(Himachal). The best specimens are available in Secunderabad (Andhra Pradesh).

2. Basalt or trap: It is an igneous rock (silicious variety). The main constituents are silica,

alumina and felspar.

Characteristics:

i. Very hard and tough.

ii. Heavier than granite

iii. Has greenish grey to dark grey colour.

iv. Crushing strength varies from 70 to 80 MN/m2.

v. Specific gravity = 2.96

Uses:

i. Suitable for paving sets and as a road metal.

ii. Used for the manufacture of artificial stone.

iii. Used as aggregate in concrete.

Occurrence: Madhya Pradesh and Deccan traps (along the western Coast) and Rajmahal trap

(Bihar).

3. Slate: It is a metamorphic rock (Argillaceous variety). It is composed of alumina mixed

with sand or carbonate of lime.

Characteristics:

i. Its specific gravity is 2.8.

ii. A good slate is hard, tough and fine grained.

iii. It has grey or dark blue colour.

iv. It can be split into thin sheets.

v. Its crushing strength varies from 60 to 70 MN/m2.

vi. It is non-absorbent.

vii. When struck with a light hammer, it produces a sharp metallic ring.


viii. Its durability is good.

Uses:

i. Used for making electrical switch boards.

ii. Because of its non-absorbent property, it is suitable for use in cisterns, urinals partitions,

etc.

Occurrence: Gurgaon (Haryana), Gurdaspur (Punjab), Cuddadh (Andhra Pradesh), Chanda

(Maharashtra), Chindwara (M.P.), Bijapur (Mysore), Alwar (Rajasthan), Chamba, Shimla,

Kangra, (Himachal Pradesh), Baroda (Gujarat).

Sandstone: It is a sedimentary rock of silicious variety. It contains sand or quartz cemented by

lime, mica, magnesium, aluminium, oxide of iron or by a mixture of these materials. Sometimes

fragments of limestone, mica, or felspar are also present.

Characteristics:

i. Its structure shows sandy grains.

ii. Its usual colours are white, grey, brown, pink, etc.

iii. Its specific gravity is 2.25.

iv. Crushing strength varies from 35 to 40 MN/m2.

v. Fine grained stones are strong and durable.

vi. The sandstone of thin-bedded variety is called flagstone. It splits easily into large slabs

along the bedding.

vii. The rock composed of angular sharp edged sand grains is called grit; it is adequately

strong and heavy and is used in heavy engineering works.

viii. The sand stone that can be cut easily with mallet and hammer into blocks for building is

referred as free stone.

ix. Its durability depends upon the nature of cementing material. The quantity of sandstone is

poor if it is porous or contains lime.

Uses:

i. The fine grained and compact variety is suitable for ashlar work, mouldings, carvings,

etc.

ii. The rough and coarse-grained stone is employed for rubblework.

Occurrence: The best variety stones which can easily be quarried in large flawless blocks are

available in Mirzapur, Chunar, Fatehpur Sikri, Gwalior (M.P), Hemanagar near Ahmedabad

(Gujarat), Nag pur (Maharashtra), Kangra and Dharamsala (H.P.), Shahpur and Kasauli Rajpur,

and Jabalpore, Dehri, Mandhum and Ranchi (Bihar), Cut tack and Mysore.

5. Limestone: It is sedimentary rock of calcarious variety. When in pure state it contains CaCOj

but frequently is mixed with MgCOJ and small amount of silica and alumina. When both

MI!CO'l and CaCO'l are present nearly in equal proportion it is known as 'Dolomite'.


Characteristics:

i. Its specific gravity is 2.6.

ii. It is available in brown, yellow and dark grey colours.

iii. Crushing strength = 52 MN/m2.

Uses:

i. It is used in large quantities in blast furnaces, bleaching, tanning and other industries.

ii. If compact and fine grained it may be used as stone masonry for walls and paving set in

floor.

iii. It is used as road metal (when better materials like trap, basalt or granite are not

available.)

Occurrence: It is found in Alwar (Rajasthah), Hoshiarpur (Punjab), Simla (H.P.), Mirzapur,

Ranchi (Bihar) and Mysore, etc.

6. Marble: It is metamorphic rock of calcarious variety. It is changed from limestone. It is

crystalline hard compact stone having CaCO3 as the main constituent.

Characteristics:

i. It is available in white, yellow, grey, green, red, blue and black colours.

ii. It is very hard and takes a fine polish.

iii. Its specific gravity is 2.72.

iv. Crushing strength varies from 50 to 60MN/m2.

v. It can be easily worked.

Uses:

i. It can be used for carving and decoration work.

ii. It is also used for steps, wall linings, electrical switch boards, table slabs and columns.

Occurrence: white marble of high purity are found in Jodhpur and Ajmer

(Rajasthan) and Jabalpur (M.P). Green marble is found in Baroda (Gujarat), black

marble in Jaipur and yellow stone in Jaisalmer (Rajasthan).


Lesson - 10: Carpets and Rugs

Objectives:

To investigate soft floor covering.

Structure:

10.1 Introduction

10.2 Benefits of Carpets and Rugs

10.3 Selecting Carpet

10.1 Introduction

Carpet is a popular floor finish that is manufactured in broadloom rolls or carpet tiles. There are

two processes for constructing carpet – tufting and weaving. The tufted process is more common

involving yarns tufted into a backing then covering the backing with latex to secure the yarns.

Woven carpet is a strong, heavy carpet in which the pile and backing yarns are woven together.

Carpet, of good quality, is popular because of its durability, soft touch and appearance, and

acoustic properties. It aids in sound reduction more than any other floor finish.

The following apply when selecting and installing

carpet:

Provide reducers, metal strips, or other edging in

areas where carpet abuts other floor surfaces.

Patterned carpets help to “mask” soiling in traffic

areas. Choose patterned carpets with

distinguishable designs of two or more different

colors. Tone on tone color combinations do not

hide soil.


10.2 Benefits of Carpets and Rugs

Carpet - nothing looks like it, feels like it or performs like it. Carpet is a key decorative and

functional element in a home or business. Carpet - It just feels better.

Comfort – Insulation

Carpet provides an added measure of warmth and insulation with its millions of fibres and places

between them to hold warmth or to insulate against extreme heat or cold. It's warmer to sit on or

work on, providing more stable temperatures for foot and leg comfort near the floor. In colder

climates or seasons, it retains warm air longer, an important benefit in our energy-conscious

world. In warm climates, it also insulates against invasive heat.

Aesthetics - The Foundation of Decorating

Because carpet is a foundation of decorating, covering a large quantity of the surface of our

living spaces, it is an important consideration in the overall scheme of colour and texture. It can

provide simplicity and casualness for softness and liveability; or it can provide pizzazz with

vibrant colour and heavier textures for making a decorating "statement." Carpet can be one of the

easiest ways to personalize an environment - its colour can be a neutral foundation "in the

background," or it can be a vibrant focal point.

Safety from Slip/Fall

Especially for small children, seniors, and generally the entire family, safety in the home is a

primary focus. We seek a stable, non-slick walking surface that prevents slips and falls and for

the time when someone does trip, a surface that protects from bruises and other injuries. Carpet

is great for cushioning our footsteps, minimizing slips and minimizing injuries from falls. It's

hard to watch a toddler take his first steps on a cold hard floor. Carpet's softness and cushioning

nature is ideal for family activity - whether it is the first steps of a toddler, the slow steps of the

grandparent, or the fast action of the mother or teen-ager.

Sound Reduction Qualities of Carpet

Carpet is as Easy on Your Ears as Your Feet

With the introduction of computers, speaker telephones, big screen TV's and video games, our

homes have become a lot noisier. Fortunately, the solution to this problem of airborne sounds

can be found right below our feet -- carpet.

Carpet not only serves as a beautiful floor covering, it also provides sound insulation.

Additionally, carpet creates an aesthetic ambiance conducive to lowered voices and heightened

privacy. The sound-reducing qualities of carpet include:

Carpet absorbs sound

Recently, homebuilders have moved towards reshaping the home by combining all of the living

area rooms into one big, open space. This layout promotes the family togetherness, but also

creates a noisy atmosphere. With the addition of carpet, sound is absorbed rather than bounced

off the floor and back onto the walls and furniture. Results from tests show that there is a

pronounced "hush" in carpeted rooms.

Carpet and cushion reduces noise better


Carpet serves as an effective noise-reducer because it absorbs the sound of foot traffic within the

home. These results are even more pronounced with the addition of carpet cushion. Research

shows that properly specified carpet and cushion combinations produce better noise-reduction

than carpet alone. Carpet cushion also increases comfort and ergonomic qualities, adds

insulation, and extends the life of your carpet by protecting it against wear and tear.

Carpet and cushion insulate between floors

Carpet works as a sound barrier between floors by helping to block sound transmission to rooms

below. Carpet and carpet cushion are especially effective in masking the "hollow" sound from

foot traffic often associated with staircases.


Lesson - 11: Resilient Floor Coverings

Objective:

To consider resilient floor covering as an option for flooring.


11.1 Types and Characteristics of Resilient Floor Coverings

11.2 Selecting Resilient Floor Coverings

11.3 Linoleum

11.4 Cork Tile

11.5 Rubber Tile

11.6 Asphalt Tile

11.7 Plastic Floorings

11.0 Introduction

The term “resilient” as used here, refers to the underfoot comfort of the floor covering, its ability

to recover from indentations from foot traffic and other loads of short duration.

The base of the floor coverings to be discussed in this part of the text is a resilient material such

as cork, asphalt, plastic, or rubber. This material is combined with a binding cement to produce

the finished floor covering. The composition varies with each type of floor covering, and the

particular combination of base and binder determines the characteristics of the floor covering and

the area in which it should be used.

At one time, resilient floor coverings were used only in kitchens and bathrooms. Today you will

find the various types of these floor coverings used in every room of the home: laundry room,

dining room, den, recreation room, play room, workshop, and nursery. Often you will find them

in living rooms and bedroom, where with throw rugs of the right design, colour, and size, some

very interesting effects can be achieved.

11.1 Types and Characteristics of Resilient Floor Coverings

There are two types of resilient floor coverings. The first and the most common consists of a

finished material applied in thin sheets, strips, or small units such as squares, rectangles, and

other shapes. Included in this type are asphalt, rubber, and cork tile, and linoleum. The second

type consists of a mix which is troweled to a finish. In the discussions that follow, only the first

type will be covered, since only that one will be of interest in decoration or redecorating.

Most of the resilient floor coverings are available in a wide variety of colours and patterns, or

designs, making them adaptable to just about any conceivable decor. The only exception to the

available variety would be in the cork tiles, which are available only in varying shades of brown.

The most important characteristics of resilient floor coverings are cleanliness and comfort. The

degree of resilience and quietness varies with the thickness of the flooring, the top surface, and

the base on which the surface is applied.


11.2 Selecting Resilient Floor Coverings

In selecting resilient floor covering, you must consider the same factors that you would consider

in selecting carpet-functionality, wear, cost, design, and the effect in the overall decor.

Functionality is of the utmost importance. The floor covering must serve a definite purpose or it

is not functional. Today‟s available floor coverings can be used in just about any room in the

house. One or more of the available coverings are almost certain to be functional.

The wear that a floor receives has a definite bearing on how long it will retain its utility and

beauty. All of the coverings to be discussed in the next few pages have varying degrees of

resilience. Thus, one is likely to be more suitable than the others for a particular purpose. Cork

tile is the most resilient, followed by rubber tile. Asphalt tile is the least resilient, and it is apt to

show marks more readily than the other materials.

The resilience of the covering is closely related to its gauge, or thickness. Basically, the thicker

the covering, the greater will be its resilience. The thicker covering will also be more attractive,

and its comfort, value, and quietness will be greater. Cost, of course, is always important.

Today‟s resilient floor coverings come in a wide range of prices. But bear in mind that, when all

the factors are considered, the most expensive covering is usually the cheapest in the long run.

Pattern, design, and colour, and their effect on the overall decor, must be given every possible

consideration. The wrong pattern or the wrong colour can easily ruin the overall decor. Bold

patterns can easily detract from the other furnishings by drawing to themselves more than their

rightful share of eye attention. The wrong colours can do the same thing. On the other hand, the

same illusionary effects obtainable with carpet and rugs are also obtainable with resilient floor

coverings.

11.3 Linoleum

Of the resilient floor covering, linoleum is one of the oldest and perhaps the most commonly

used. There are different kinds of linoleum and each kinds produced in various thickness. The

most common of these are battleship, plain, jaspe, marbleized, inlaid, linoleum tile, and felt-base.

With the exception of linoleum tile, linoleum comes in sheet form, usually in roll width that can

be cut to size. Linoleums are available in wide rage of colours and patterns. It may be of interest

to note that architects and contractors recommend that linoleums should not be installed on floors

that are even with or below the outside landscaping, but rather only on suspended floors that are

above the grading.

Battleship linoleum was first manufactured in large quantities to meet United States Navy

specifications for warship flooring. Normally it is produced in heavy gauge (1/8 inch thick). It

comes in rolls of varying widths, and is laid in strips as wide as possible, except where joints are

required for the sake of designs. It is often made in special design that include borders and strips.

Although battleship linoleum is especially useful in areas of extremely heavy traffic, such as

school corridors, laboratories, and offices, it is also appropriate for kitchen, bath rooms, and

living rooms.

Plain linoleum has the same composition and uses as battleship linoleum, but it comes in both

heavy gauge and standard gauge (3/32 inch thick).

Jaspe Linoleum, has the same composition and uses as plain linoleum. It is available in both

heavy and standard gauges. The surface pattern of jaspe linoleum was developed so that the


discoloration caused by dirt, slight irregularities in laying, and the monotony of a single tone

would not be noticeable. Also, parts subjects to constants traffic and use do not show wear so

readily. Jaspe linoleum is much used in solid colours with plain borders.

Marbleized linoleum is currently popular. Marbleized linoleum gets its name form the fact that it

reproduces the colours, distinctive veining, and other characteristics of marble.

Marbleized linoleum has the same composition as plain and jaspe linoleums. It comes in heavy,

standard, and light (1/16 inch thick) gauges.

In inlaid linoleum the designs extend from the surface through to the backing. Inlaid linoleums

are popular, particularly for areas of heavy traffic such as the kitchen, because no matter how

much they become worn the colour and pattern remain. Embossed inlaid linoleum; the difference

is that the spaces, or joints, between the designs are depressed, thus making the designs stand

out. Available in all the standard gauges, embossed inlaid is used to imitate slate, tile and wood

planking.

Felt-base floor covering is often referred to as painted linoleum. It has a felt backing and is

produced only in the very thin gauges. The design is printed on the surface only. Felt-base floor

covering is used in locations where economy is the main consideration.

The body and surface of individual tiles are the same as those of the regular, or roll-type,

linoleums. Linoleum, tile can be better adjusted to any irregularities in the floor than can the roll-

type linoleum. Most important, if and when repairs are required, a few tiles can be easily and

quickly replaced. Linoleum tile is available in various colours in plain, jaspe, or marbleized

surfaces, and in standard and light gauges. The usual sizes are 9 by 9 inches and 6 by 12 inches.

Linoleum tile costs less than most of the other resilient floor coverings.

11.4 Cork Tile

Cork tile is made of first-quality pure cork. Its

composition is the same from face to back, and it

is evenly bonded with a special binder. It is

accurately cut in sizes of 6 by 6, 6 by 12, 9 by 12

and 12 by 24 inches and in thicknesses of 1/8,

3/16, and 5/16 inch. There are several shades of

cork tile, varying from light to dark brown.

Different shades may be used together to

produced interesting designs.

Cork tile is the most resilient of the floor tiles.

Because of its close texture, it can be readily

washed. It is used primarily where people gather,

such as family room, kitchen, or corridor. You

should not, however, use cork in entrance halls or

vestibules where the surface may be spoiled by

sand and grit. Cork should never be used

outdoors.


Waxing cork tile after it is laid will increase the life of the flooring

and will bring out the full beauty of the natural cork colour. Nearly all

cork tile is now finished at the factory with an initial coat of wax.

Cork tile can be laid on any type of suspended subfloor. It can be laid

over concrete, provided the grade slopes away from the foundation of

the house and the tile is laid with a waterproof adhesive.

11.5 Rubber Tile

Rubber tile is made of a rubber composition that is free of

objectionable odours and contains well-dispersed

reinforcing fibres and fillers. The colour and design extend

through to the back of the tile, except for those tiles which

are mounted on a special sponge-rubber backing. Rubber

tile is made in plain and marbleized colour and in two or

more tones. The choice of colours is almost as wide as that

of the linoleums.

The usual thicknesses of rubber tile are 1/8 and 3/16 inch,

but other gauges upto 1/2 inch can be obtained for special

purposes. Sizes include 6 by 6, 9 by 9, 12 by 12, and 18 by

36 inches. Special shapes for various designs can be

obtained from the manufacturers.

Because of its durability, its resistance to ordinary stains,

such as ink and grease, and its high degree of resilience,

rubber tile is particularly suitable for use in the kitchen,

bathroom, and family room. It is used most widely,

however, in commercial structures - banks, churches,

stores offices, and reception rooms in large buildings.

Rubber tile can be used on suspended subfloors; and with

the proper cements it can be used on floors that are either

on grade or below grade.

The wiping up of spilled water or other materials is made

easier by this type of floor. Most important, the resiliency

of the tile makes it comfortable to walk on, while

maintaining the desired quietness.

11.6 Asphalt Tile

Asphalt tile is generally composed of inert materials, such

as asbestos fibre, with a natural asphalt binder and mineral

pigment. The pigment provides the colour, which extends

through the thickness of the tile. The usual thicknesses of

asphalt tile are 1/8 and 3/16 inch, but other thickness are

available, though in fewer colours. The usual size in 9 by 9

inches, but it can be had in the 18 by 24 inch size. An

initial coat of wax is usually applied at the factory.


Asphalt tile comes in a wide range of colours; it also includes many of the marbleized effects

found in linoleum and rubber tile. Asphalt tile is recommended for use in basements and on

grade level concrete floors, because it is not affected by dampness, and there is nothing in its

composition to cause rotting or deterioration. It is resistant to fire and to heavy wear, and it will

withstand the action of mild acids and alkalis. There are special grease proof types of asphalt tile

for use where resistance to grease, oils, or fats must be considered.

Besides basements, asphalt tile is used in a wide variety of designs and colours for such locations

as corridors, kitchens, bathrooms and recreation rooms.

11.7 Plastic Floorings

A flexible plastic flooring that is composed of vinyl resins,

other plastic compounds and alkali resisting pigments is made

in sheet or tile form. The material is dense, resilient, and highly

resistant to abrasion, grease, and solvents. The sheet form has a

backing of resin-saturated felt and is slightly more than 1/16

inch thick. The tile form does not have a backing; it is

accurately cut with square edges, and it comes in thickness of

1/18 and 3/32 inch. Sometimes the sheet form is cut into tile

sizes. Vinyl plastic tile can withstand a furniture load of 200

pounds per square inch without being deformed in any way. In

general, plastic tile should be laid only on suspended subfloors.

The better quality, however, can be installed on subfloors below

grade.

There is a tile formed of a completely blended composition of

vinyl plastic resins, asbestos fibres, and alkali-resisting

pigments and fillers which is suitable for use on any type of subfloor. This vinyl asbestos tile is

made in thicknesses of 1/8 and 1/10 inch. It is extremely durable and highly resistant to alkaline

moisture, oil, grease, and household chemicals. Thus, vinyl asbestos tile is particularly suitable

for use in kitchens. Like most tiles, plastic tile can be had in a wide range of colours and patterns.


Summary:

Unit discussed above have notes about different floor covering their warmth, sound absorption,

and definition of space. We have discussed two types of floor coverings: resilient, and soft and

the factors that contribute to the life and durability of flooring. Floors such as: plastic laminate,

wood, and soft coverings such as carpets and rugs.

Revision points:

Two type of floor coverings i.e. soft and resilient.

Soft covering includes:- carpet and rugs and resilient floor covering includes plastic floor

coverings,linoleum,rubber, asphalt etc.

Soft flooring refers to carpets and rug. . Carpet is a key decorative and functional element in a

home or business. Carpet is a popular floor finish that is manufactured in broadloom rolls or

carpet tiles. There are two processes for constructing carpet – tufting and weaving. Carpet have

few beneficial point such as: - insulation, Aesthetic looks, safety from slip and fall, sound

reduction quality etc. Carpets are available with different texture and pattern and with different

piles.

Oriental rugs are hand-woven item produced primarily in the Islamic world, although oriental

rugs are also made by non-Islamic peoples in the Far East and by non-Muslim minority weavers

throughout the Islamic world. Machine-made rugs of any sort are not "oriental rugs" in the

established sense, but are better referred to as "oriental-design rugs."

The term “resilient” as used here, refers to the underfoot comfort of the floor covering, its ability

to recover from indentations from foot traffic and other loads of short duration.

Key words:

Carpet: - Carpet is a popular floor finish that is manufactured in broadloom rolls or carpet tiles.

There are two processes for constructing carpet – tufting and weaving.

Cut pile: Loops are cut, leaving individual yarn tufts. Still one of today's most popular

constructions, its durability is achieved with factors including the type of fibre, density of tufts,

and the amount of twist in the yarn.

Rugs: - Oriental rugs are hand-woven item produced primarily in the Islamic world, although

oriental rugs are also made by non-Islamic peoples in the far east and by non-Muslim minority

weavers throughout the Islamic world. Machine-made rugs of any sort are not "oriental rugs" in

the established sense, but are better referred to as "oriental-design rugs."

Resilient flooring:- The term “resilient” as used here, refers to the underfoot comfort of the floor

covering, its ability to recover from indentations from foot traffic and other loads of short

duration.

Intext questions:

1. Explain in detail the benefits of using carpets and rugs.

2. What points would you keep in mind while selecting a carpet?


3. What are the different types of piles in carpet construction? Explain in detail with the

help of sketches.

4. Discuss in detail the various fibres used in carpet manufacture. Give the advantages and

disadvantages of each.

5. What are oriental carpets? Explain in detail.

6. Discuss in detail the various categories of oriental rugs.

7. Explain in detail the various types and characteristics of Resilient floor coverings.

8. What points would you keep in mind while selecting a resilient floor covering?

Terminal exercise

Students have to collect samples or pictures of floor coverings, and have to different visit a retail

flooring stores of their areas and Illustrate how size illusion can be created by the choice of

flooring. and the effect of using one colour and one type of flooring in all rooms vs. a different

colour and texture in each room of the house.

Compare costs of various types of floorings which includes soft and resilient floor coverings.

Assignments/learning activities

Students have to complete an assignment in which they will List up all the advantages and

disadvantages of two types of floorings:-soft and resilient flooring. Discuss the various kinds of

materials, fiber content and construction, and the suitability of each. With proper samples and

written report.

Supplementary material/suggested reading


2. Building construction by sushil kumar


Unit – III

Textiles and Fabrics in Interiors

Lesson -12: Fabric Construction and Fibres

Lesson -13: Vegetable Fibres

Lesson -14: Man-Made Fibres

Lesson -15: Upholstery Materials


Lesson - 12: Fabric Construction and Fibres

Objective:

To examine the role of textiles and fabrics in interiors.


12.2 Animal Fibres

12.2.1 Wool

12.2.2 Mohair

12.2.3 Silk

12.1 Introduction

Any woven fabric, whether it is hand-made or manufactured on any particular type of loom, has

at least a warp and a weft (alternatively known as woof). There may be further elaborations,

which will be explained later, but these are the two basic requirements with which to form any

fabric material. The warp is the lengthwise yarn or series of yarns that interlace with the weft

yarns that go across the width of the material. The warp should always be the stronger, although

a reasonable balance should be maintained.

Yarns are made up of fibres that are animal, vegetable, and man-made or a combination of these.

Fibres all have certain natural properties and have to go through different processes before being

spun into yarn. These processes therefore are very important for classification, purification and

special treatments to ensure that the particularly desired results are obtained as far as possible.

Special treatments are also carried out at later stages, during the spinning, weaving or even

dyeing stages, as we shall see later.

12.2 Animal Fibres

12.2.1 Wool

Wool is strong and, being among the most resilient of all the fibres, resists abrasive wear and is

suitable for carpets and upholstery. Its quality depends on the original raw material obtained

from various species of sheep, and the longer the fibre the coarser the wool. Lengths vary from

1.5" - 15" (3.75cms - 37.5cms), with Merino from Australia and South Africa being the finest,

with most 'crimps' per inch. The East Indian or Scottish Black Face is tougher and coarser and

particularly suitable for carpets. Moquette, a distinctly textured upholstery material, is

traditionally all wool, as clothes do not become shiny on contact. Sometimes, however, cotton is

used for the cheaper varieties.


The most important of the fibres of animal origin wool is the hair of the sheep (Ovis ales). The

characteristics of wool fibres differ depending on the breed and general condition of the sheep.

Wool, the hair of various breeds of sheep, is a warm springy fibre. It‟s scaly structure led in the

past to unwanted felting (matting of fibres) and shrinkage in laundering but modern finishing

treatments have now overcome these difficulties; similarly, attack by the clothes moth is no

longer a problem.

Wool has a natural crimpiness, which gives it good elasticity, bulk, crease-resistance and

durability. Its strength when wet is less than when it is dry. Important properties of wool are a

dry strength of 11.5 to 13 cN/tex, a breaking elongation of 30 to 40% and a moisture regain of 16

to 18%.

Technologically, the diameter, or fineness, of the wool fibre is probably the most important

property. It is determined to a large extent by the grade assigned to a lot, or batch, of wool.

Diameters range from 16 microns in the finest Merinos to over 40 microns in the coarsest long-

wool types. Staple length generally increases with increasing fibre diameter, ranging from four to

eight centimetres for fine Merino up to 35 centimetres for coarse Cotswold wool. Staple length is

lower than mean fibre length because of the crimp that results in a helical configuration in an

individual fibre and an uni-planar wave in the staple.

All wool initially contains impurities. Collected dust, dirt and grease from the sheep's pores

make up about half the weight of the fleece, and therefore the raw wool has to be cleaned,

scoured and sorted into grades of length and quality. Steeped in diminishing solutions of soda,

ash and soap and finally warm water, wool in this form can be spun into woollen or Worsted.

Both woollen and Worsted (named after the town in Norfolk that introduced the original weave)

are of wool fibres spun on machines in the same way as flax, cotton and other fibres, but are

classified as such because woollen fibres lie in all directions, thereby giving a coarser, rougher

finish, while Worsted fibres lie parallel and are more carefully selected since it is necessary to

have long fibres to twist tightly into a fine yarn.

12.2.2 Mohair

Mohair from the Angora goat, has fibres similar to wool except that the 'scales' are smoother,

giving a silky, lustrous fibre from 4" - 15" (10cms - 37.5cms) in length. Since it needs moth-

proofing (as does wool), proprietary chemical brands are usually used by the manufacturer to

deal with this. It is excellent for plush pile fabrics (see later) that depend on sheen to impart a

feeling of richness, opulence and quality.


12.2.3 Silk

Silk is the only natural fibre obtained in a continuous

filament, so the 'fibre' definition is not strictly accurate except

when the 'left-overs' are reduced to a staple (standard) length

of 3" (7.5cms) and then spun as for wool, the resulting

material then being known as spun silk. Very lustrous and

able to preserve its elasticity due to its structure, it is very

expensive and tends to be used only in exclusive contracts. It

burns with an unsteady, flickering flame, leaving a crushable

cinder. Afterwards there is a smell like burning hair, which

indicates its difference from rayon or nylon, which are also

continuous but man-made filaments.

In Old English, silk was sioloc. The name is thought to have

originated from the Greek seres, meaning the people from

Eastern Asia i.e. the Chinese. The term sericulture derives

from this Greek root.

Silk has a long and fascinating history, starting over 4000

years ago with the development by the Chinese of the art of

rearing silkworms to make a textile fibre. Since that time silk

has remained highly valued for its luxurious qualities but,

because its main uses have been in very expensive apparel

and other luxury goods, demand has been considerably more

variable than for many other fibres.

There are several species of silk producing worms but most

of the world‟s silk results from the worm of the moth

Bombyx mori which lives exclusively on the leaves of Morus alba the white mulberry tree. Other

silkworms include the wild or semi-wild varieties, such as Atlas, Eri, Tussah and Muga, which

are found mainly in India and Asia.

The silkworms are reared in large numbers at silk farms, where plantations of bush-like mulberry

trees are cultivated to provide leaves which are fed to the worms in special rearing rooms. From

the day it hatches to the time it stops feeding, a period of 25 to 30 days, the worm gains in weight

about 10,000 times. During this time it eats some 22g of leaves and converts more than 70% of

its intake of nitrogenous material into silk. To produce 1kg of raw silk about 6.25 kg of fresh

cocoons are necessary, while for raising 6.25 kg of cocoons about 104 kg of mulberry leaves

containing 26 kg of solid matter are required. On average 75% of the fresh „green‟ cocoon, by

weight is chrysalis. The outer layer of floss and the inner layer are collected as silk waste and

used in spun silk manufacture. Wild silks such as Tussah are also generally used for spun silk as

the cocoons are seldom in a reelable condition.

Tussah, a kind of wild silkworm, comes in two varieties monovoltine and bivoltine. It lives and

multiplies wherever oak trees or leaves of the Mongolian oak, rubber trees or Chinese toon trees

are available. There is one main type of tussah silkworm, Antheraea pernyi, and one general type

of oak tree on which it feeds, Quercus serrata.


Silk is a fairly strong fibre and although it does not compare with nylon and polyester in this

respect its strength makes it suitable for use in sewing thread in high quality articles, particularly

those made from silk. Silk absorbs more moisture from the surrounding air than do most of the

synthetic fibres, and this property confers considerable advantages; it prevents a clammy feeling

where fabric is in contact with the skin, since moisture can be absorbed without the fibre

becoming noticeably damp, and transmitted through the material and into the atmosphere.

Silk has a fairly high natural resistance to creasing. Attempts to improve on this and also to apply

easy-care treatments have not been very successful, as they impair the unique handle, or feel, of

silk which is one of its most valuable properties.

The environmental impact of silk processing is relatively minor in its initial stages when

compared to cotton or wool. The cocoons are cooked to kill off the insects and then the fibre is

washed in synthetic detergents to remove most of the sericin (gum) in readiness for dyeing.

Subsequent processing, through spinning, weaving, dyeing and finishing have an impact on the

environment similar to most of the other fibres. Noise and dust is produced in weaving and a

complex effluent with variable BOD/COD, pH and solids content is produced in finishing.

Most silk comes from China, Japan, India and Italy, and is unfortunately produced by the mass

destruction of silk moth larvae (silkworms), whose sad contribution to the worlds of fashion and

interior design is due to the fact that

they spin cocoons of particularly

fine quality. The process of

sericulture involves the moth larvae

being killed by heat before breaking

out of the cocoon, which is softened

in water and has some gum

removed. While in the hot water

tank several perfect filaments are

taken from each and brought

together through a guide. Half a

dozen or so filaments are then

reeled together and given a slight

twist to form silk yarn by a

complicated process called

throwing.


Lesson - 13: Vegetable Fibres

Objective:

To describe the types of fabrics used in interiors.


13.2 Flax

13.3 Cotton

13.4 Jute

13.1 Introduction

Yarns are made up of fibres that are animal, vegetable, man-made or a combination of these.

Fibres all have certain natural properties and have to go through different processes before being

spun into yarn. These processes therefore are very important for classification, purification and

special treatments to ensure that the particularly desired results are obtained as far as possible.

Special treatments are also carried out at later stages, during the spinning, weaving or even

dyeing stages, as we shall see later.

Vegetable fibres are those fibres which are obtained from natural resources like plants,

vegetables etc.

13.2 Flax

Flax is the strongest natural fibre known, and is used to produce linen. Smooth and straight, it is

very resistant to dirt and abrasion. It has a natural lustre but not much resilience, and therefore

needs processing to improve its tendency to creasing. As it dries quickly and is stronger wet than

dry, it is therefore good for loose covers as it stands up to laundering. Its dimensional stability,

however, depends on the weave.

Flax is the most important of the bast fibres in textile use. The fibres occur in the stem of the flax

plant (Linum usitatissimum) where they are grouped in some 30 bundles round a woody core.

The word flax is derived

from the Old English fleax.

The Teutons referred to it as

flakso, coming from the

Teutonic root fleh, to plait.

The term „flax‟ is applied to

fibre and yarn, whilst the

name for the sewing threads

and fabrics is „linen‟.


Each bundle contains 10 to 14 individual fibres, on average 20 to 30mm in length and 15 to

20mm in diameter. After retting, the fibre bundles are separated from the cortex and woody

tissue by scutching, which is a mechanical process. A certain amount of cortical tissue is left

adhering to the fibre bundles and gives the characteristic colour to the raw flax strands.

About 80% of the total world flax crop is grown in the former USSR and other Eastern bloc

countries, whilst France, Belgium and Holland are the main flax-growing countries in Western

Europe.

Flax fibre is stronger than cotton. It readily absorbs moisture (12% moisture regain) and so is

extensively used in the towel trade; this property also contributes to the comfort of linen

clothing. Chemically, the flax polymer is the same as the cotton polymer; both are cellulose

polymers. Physically, the flax polymer differs from the cotton polymer, in that it has a degree of

polymerisation of about 18000. This means the flax polymer is made up of about 18000

celloboise units. It is about 18000 nm long and about 0.8 nm thick. This makes it the longest

known, linear textile polymer. The polymer system of flax is more crystalline than that of cotton.

Flax fibres therefore tend to be stronger, crisper and stiffer to handle, and textile materials of

linen wrinkle more readily than those of cotton fibres.

Flax is grown in very densely planted fields to draw the height of the stem up to 3' (90cms), and

then pulled by hand. Sometimes fibres are drawn through hot water to soften the natural gum that

binds them, when the strands become like flaxen hair after the woody part has been 'scutched'

(beaten until it falls away).

13.3 Cotton

Cotton fibres are the seed hairs of the plant Gossypium. They are usually off-white in colour

although some varieties have been bred to incorporate a natural colour. Each fibre is formed by

the elongation of a single cell from the surface of the seed. The word cotton is derived from it‟s

Arabic name pronounced kutan, qutn or qutan depending on the dialect.

Under a microscope, a cotton

fibre appears as a very fine,

regular fibre, looking like a

twisted ribbon or a collapsed

and twisted tube. These twists

are called convolutions.

Almost half of the world‟s

requirements for textile fibres

are met by cotton. It is grown

in many parts of the world

where a hot dry climate is to

be found, the main producers

being USA, the former USSR, China, India, Egypt, Africa and South America.

Cotton consists typically of between 88 to 96% cellulose with the rest being protein, pectic

substances (congealed gum-like carbohydrates), ash and wax. After scouring and bleaching,

cotton is then about 99% cellulose. The fibres are weakened and destroyed by acids but are

resistant to alkalis.


The fibre length varies with the type and quality, within the range 10 to 65mm; the fibre diameter

ranges from 11 to 22 ¼m. Cotton is a relatively strong fibre with a strength of 25 to 35 cN/tex

and a breaking elongation of 7 to 9%. It is stronger when wet. Cotton also absorbs moisture

readily, which makes cotton clothes comfortable to wear in warm weather (water retention of

50%, moisture regain of 7%).

Cotton fibre burns readily and is not inherently resistant to oxidising agents, and biodegradation,

as well as acids. Despite these shortcomings cotton has a good wear life. Its properties can also

be readily modified by chemical finishes which provide enhanced performance, e.g. crease

resistance and flame resistance.

It is used in both 100% form and in blends with other fibres for household textiles and apparel.

Synthetic fibres have largely replaced its use in industrial textiles.

Cotton is by far the most popular fibre in use today, at least in terms of volume of production.

The most widely used class of dyestuff on cotton are reactive dyes, which unfortunately are also

the most poorly exhausted, producing a more coloured effluent. Colour consents on discharges

have therefore been enforced in certain areas where there are significant numbers of cotton

dyers.

Cotton is warmer than linen because of its slight hairiness, although it has a limper handle

(simply its feel when handled). Long fibres are used to produce strong materials, it has a good

affinity for dyes, and can be Mercerized to give a sheen. Cotton has a natural twist, and the short

fibres, compressed and not spun, can be used as a backing in textural fabrics. These short fibres

lack strength and can only be used in the weft, held firmly or closely woven with other weft

yarns. The material thus produced has little resistance to abrasion, but is often of noticeable

interest due its coarseness. Short fibres can also be used to make cotton felt for bedding and

upholstery.

13.4 Jute

Jute is not resistant to abrasion and does not drape at all well. It is used mostly with other fabrics

for backing to linos and carpets since it makes a very coarse fabric.

It is little used now for anything other

than utility purposes, although is still

seen stretched onto backing board for

exhibition and museum display

backgrounds, and occasionally used in

upholstery techniques. It is usually

easily recognized, having a coarse

appearance and a 'sacking' type smell.


Lesson - 14: Man-Made Fibres

Objective:

To describe the types of fabrics used in interiors.

Structure:

14.1 Introduction

14.2 Acrylic

14.3 Rayon

14.4 Viscose

14.5 Polyester

14.6 Nylon

14.7 Polythene

14.1 Introduction

Fibres once chemically treated whether its animal or vegetable fibre called man made fibres

example: -acrylic, rayon, viscose etc. The term acrylic is derived from the Latin word acryl

meaning bitter, pungent or irritating, and is descriptive of the compound, acrylic acid.

Acrylonitrile is chemically related to acrylic acid and the term acrylic is short for

polyacrylonitrile.

14.2 Acrylic

Research to develop synthetic fibres of the acrylic type was under

way in the early 1940‟s, chiefly at the DuPont laboratories in the

USA. In 1948 the trade name Orlon was announced. As produced

initially, Orlon was characterised by high tenacity, rivalling nylon

and polyester fibres, but it was extremely difficult to dye.

The reason was that the first type of Orlon consisted of a

homopolymer of acrylonitrile which does not take up dyestuffs. By

1952 a new way was found to exploit acrylonitrile by adding a

second molecular constituent to the polymer chain, so forming a

co-polymer.

The nature and proportion of the second component used is rarely

discussed but a large number of co-polymers have been described

in the patent literature. Vinyl acetate, vinyl chloride, methyl

acrylate and 2-vinyl-pyridine are among the monomers which are

probably used commercially.

The co-polymer fibres were found to be pleasantly soft, in fact

more wool-like than any other synthetic fibre. Also their chemical

structure could be designed to enable them to dye like wool.


Eventually more success resulted from modifying monomers to make the fibre dye with basic

and disperse dyes.

Production of acrylic fibre is a complex process, requiring advanced engineering and control

systems. In Western Europe acrylic fibre has been very popular; however, on a world basis nylon

and especially polyester are ahead of acrylic fibres in production.

The mechanical properties of acrylic fibres are modest when compared with fibres like nylon and

polyester. The fibre strength is often only half that of nylon, but the breaking extension is usually

so high at about 40% that this gives a relatively tough fibre. Acrylic fibres are easy to bend and

deform, and recover well, although less well than nylon. However, the soft open structure of

many of the products made from acrylic fibres is helpful in avoiding the incidence of sharp

creases.

Acrylic fibres are not affected by humid air but soften and

weaken in hot water so that washing in mild conditions is

recommended. Acrylic fibres are generally resistant to

chemicals and are used for some types of protective

clothing. The fibres are quite resistant to acids and most

types of common organic solvent. They generally have

good resistance to oxidising agents but are discoloured by

alkalis. Moths, carpet beetles and mildew are resisted by

the fibre, causing at most only superficial harm.

As with the other major synthetic fibres, acrylonitrile the

base component for acrylic fibre is a product of the

petroleum industry. Another example of a non-

recoverable and dwindling resource being used to

produce, what has become, an important textile.

In the production of the fibre from the polymer, solvents

are used to dissolve the polymer prior to extrusion and

spinning, this differs from the production of polyester and

nylon fibre which is melt spun.

14.3 Rayon

Rayon comes in viscose and acetate varieties, both being

derived from spruce pulp and other alternative materials

such as cotton linctus.

14.4 Viscose

Viscose fibres together with acetate fibres represent man-

made fibres made from cellulosic (wood pulp) sources.

These fibres were developed around 1900.

Viscose is stronger than acetate and is therefore suitable

for upholstery, although linings should still be used.

Acetate, which has a softer handle, is sheer to look at and resembles pure silk; but generally it

should only be used for curtains and bed covers. It is not very resistant to sun and therefore needs


care in positioning. Since both viscose and acetate lose strength when wet, areas in which they

would soil quickly need to be avoided to save constant laundering.

There are two other man-made regenerated fibres, namely cuprammonium and modal

(polynosic).

Standard-type viscose fibres have moderate strength and are relatively stiff compared with fibres

such as cellulose acetate and nylon. Strength is reduced in wet conditions, so that heavy duty end

uses would not be expected. Viscose is a limp handling fibre because its polymer system is so

very amorphous. Its polymers are not sufficiently long for a more satisfactory alignment, and so

do not allow the formation of more hydrogen bonds which would result in a more rigid polymer

system and thus a crisper handle to the fibre and textile.

The very amorphous polymer system of viscose, as well as its polar polymers, make viscose the

most absorbent fibre in common use. The slightly more crystalline polynosic rayon is somewhat

less absorbent than viscose. As would be expected, viscose and the other regenerated cellulosics

have somewhat similar thermal and chemical properties to cotton. However, the shorter polymers

and the very amorphous nature of regenerated fibres are responsible for their much greater

sensitivity to acids, alkalis, bleaches, sunlight and the weather.

Whereas all fibre making processes are governed largely by their inherent costs and the utility of

the product, three additional factors assume great importance; raw material supply, energy

requirements, and environmental impact of the production process. The use of raw material,

wood pulp, in the viscose process means that a renewable resource is involved, and this is

produced from softwoods growing in northern latitudes on land unusable for other forms of

agriculture, or from hardwoods growing at a phenomenal rate in sub-tropical areas. The

production time of 10 to 20 years for wood compares with 100 million years for the non-

renewable fossil fuels such as oil used as feedstock for synthetic polymer production. Further,

the use of wood pulp for the viscose process is only a small fraction of total pulp usage, and in

general pulp production keeps up with demand. Other materials required for the viscose process

are caustic soda, sulphur chemicals and salts, and these are in abundant supply.

The considerable pollution of air, watercourses, and land associated with older viscose plants,

and current health fears over carbon disulphide air pollution, have been significant problems.

Technological advances are however, making possible complete recovery and recycling of many

chemical materials used in the process.


In general, the status and prospects for continuous filament viscose have declined and there were

many plant closures in the 1970‟s. However, the fact that the source of raw material is

renewable, and the desirable properties of the product in which comfort and moisture are

prominent, point to a more promising future. Problems with relatively high energy costs and high

manpower requirements are still being investigated to ensure investment in viscose plant.

Rayons tend to shrink and therefore ample hems should be specified to allow for this eventuality.

There is also a problem with too high temperatures since viscose rayon can stand boiling water

and hot irons, whereas acetate rayons would melt under these conditions.

Nevertheless they do comprise a very useful and comprehensive group of textiles, being

available in all kinds of weaves and fibre combinations to produce practically any type of

material required. To identify continuous filament rayon, the yarn should be rubbed between the

fingers, when the fibres separate into fine and continuous 'hairs'. The material drapes well and is

resistant to moths, rot and mildew.

14.5 Polyester

Polyester is one of the major synthetic fibres. Its name must be familiar to most shoppers; 100%

polyester is seen often on the labels of ladies and men‟s outerwear, while the blend

polyester/cotton is very common in shirts and bed sheets. Another very common blend,

polyester/wool is popular in dress fabrics and men‟s suits. There are a number of reasons for this

wide use of polyester. Most important are its properties of easy care and toughness, while its

relatively low price obviously has a marked influence on its universal acceptance.

The raw material for the production of polyester is oil. Polyester is similar to nylon in many

respects in that fibres formed from both of them are strong with high abrasion resistance and low

moisture absorption. They are also resistant to rot and chemicals and can be set into shapes by

the application of heat. Polyester, however, even with the possible disadvantage of its later

commercial development, has become probably the most important synthetic fibre. This has

happened because of relatively slightly but important differences in its properties compared with

those of other synthetics, and production costs lower than those of nylon.


One of the most important properties of the fibre is its resistance to stretching. The handle or feel

of the fabric is more influenced by the modulus of the fibres i.e. their resistance to small

extensions and bending. The modulus of polyester is about double that of nylon, which tends to

give fabrics containing polyester a crisper handle and good dimensional stability. The ability of

polyester fabrics, after heat setting, to retain a flat shape by shedding accidental creases but also

to retain pleats and fashion creases set into the fabric is a major advantage.

Because of its high melting point polyester has good thermal stability. It softens at about 200◦ C

and will not easily burn. Unless supported in a fabric by another fibre it will melt away from heat

rather than burst into flame. At a temperature of 150◦ C it retains about 50% of its tenacity and

has good long term resistance to heat in the absence of strong chemicals.

Polyester‟s easy care properties are helped by a very low value of moisture absorption. Under

normal atmospheric conditions it absorbs only about 0.4% water compared with 4% for nylon

and 7% for cotton. Its strength is little affected when wet and it also has the added advantage of

drying very quickly.

World production figures illustrate the dominance of polyester as the current main synthetic

fibre. In 1970 nylon had the highest production value of all synthetics, at a level of 40%, with

polyester second at 34%. Since 1975, however, when nylon had fallen to 33% and polyester had

passed it to a level of 45%, polyester continued to grow on a percentage basis so that in 1998 it

had reached 58% of world synthetic fibre production, mainly at the expense of nylon, which had

fallen to less than 15% (acrylics account for most of the remaining production). These changes

occurred at a time when production shifted from the USA and Western Europe to developing

countries, which now produce the lion‟s share of polyester fibre.

The environmental impact of the production of polyester is relatively small, or at least looks that

way, since the polymer once formed is just heated until molten before being formed into fibres

with no effluent being produced. However, other factors such as high energy consumption, and

process emissions generated in both the production of the constituent chemicals and polymer

have also to be considered. The oil required for all of this process being a non-recoverable

resource. It can therefore be argued that the production of polyester, and indeed any other

synthetic fibre where the polymer is generated from petroleum, is not sustainable. In terms of the

world consumption of chemical feedstock then the production of man-made fibres, of which

polyester is the greatest, accounts for about 5% of the total.

When dyeing polyester, dye carriers are required to help achieve complete dye penetration.

Many of these chemicals tend to be toxic in nature and some are carcinogenic. Those with a

higher risk have already been effectively banned from use.

The setting of synthetics such as polyester, produces a characteristic blue stenter haze from the

oils being driven off the fabric. The emissions from this process can be quite odorous and so

textile finishers are finding that local authorities are insisting that abatement systems are installed

to remove the fume.


14.6 Nylon

Nylon is suitable for most textiles, at

least as an additive, including carpets

and upholstery fabrics, having great

strength and resistance to abrasion as

we have already seen. It is easy to

clean and, although slightly less

strong when wet, is crease-proof and

vermin-proof, and will not catch fire

even though it melts in flame. Plenty

of allowance should be made when

making up curtains etc. since it has a

tendency to fray; but the earlier

difficulties concerning the build-up

of static electricity, especially in

carpets, have been largely eliminated.

Nylon stockings were first shown to the public by the American Dupont company at the New

York World‟s Fair in 1939. Using phrases like „as strong as steel‟ and „as fine as a spider‟s web‟

to help describe the sheer but tough properties of these new silk like but affordable stockings a

huge demand was soon generated. The nylon developed by Dupont is formed by the thermal

polycondensation of hexamethylene diamine and adipic acid. This is called nylon 6.6.

The properties that ensured the early success of nylon, and which maintain their continued

success; are that it is very strong (weight for weight stronger than steel wire), it is very tough, it

has outstanding abrasion resistance, its recovery from stretch is better than that of most other

fibres, and it can be spun as fine as silk.

In addition to its high breaking strength nylon stretches appreciably before it breaks so that a lot

of energy is expended before rupture. This makes nylon suitable for use in ropes, harnesses,

arresting cables and parachute fabric.

Coupled with its low retention of water after spin drying (about 15%, compared with 50% for

cotton and 44% for wool) and its ability to shed accidental creases easily, especially when damp,

it is very easy to launder, much reducing the domestic wash-day burden.

Any fibre that has exceptional strength and toughness, that can be dyed to bright colours, and can

be spun as fine as silk obviously has a wide range of uses.

Most of the environmental problems associated with polyester also apply to the production of

nylon. The main difference being that nylon can be dyed using acid and metal complex dyes as

well as the disperse dyes which are used solely on polyester fibres.

14.7 Polythene

Polythene (polyethylene) and P.V.C. (polyvinyl chloride) are durable and easy to clean but,

while having a certain amount of decorative quality, need care in detailing to make the most of

their appearance.


Summary:

This unit gives u ideas such as: Fabric structure, Type of fibre, Colour, texture and pattern, effect

of light, heat and maintenance. Various types of fabrics like animal, vegetable and man made

fabrics and give a description for each.

Revision points:

Various types of fabrics like animal, vegetable and man made fabrics and give a description for

each. The advantages and disadvantages of the types of fibres and where they are used etc.

Key words:

Weave: - Any woven fabric, whether it is hand-made or manufactured on any particular type

of loom, has at least a warp and a weft (alternatively known as woof) is called weave.

Warp and weft: - The warp is the lengthwise yarn or series of yarns that interlace with the

weft yarns that go across the width of the material.

Vegetable fibres: - Vegetable fibres are those fibres which are obtained from natural

resources like plants, vegetables etc

Animal fibres:- are those fibres which we obtain from animals like wool we obtain from

sheep, silk from silkworms.

Man made fibres:- fibres once chemically treated are called man made fibres example:-

acrylic,rayon,viscose etc.

Intext Question:

i. What is a weave? Explain in detail

ii. Discuss in detail the various types of animal fibres used for fabric construction.

iii. Discuss in detail the various types of vegetable fibres used for fabric construction.

iv. Discuss in detail the various types of man-made fibres used for fabric construction.

v. How important is it for an Interior Designer to have a thorough knowledge of fabrics and

textiles? Explain with the help of examples.

Terminal Exercise:

i. The students should collect sample of the following Vegetable fibers: cotton, jute etc.

ii. Animal fibers: wool, silk, leather etc.

iii. Man made fibers: nylon, rayon, etc.

iv. Discuss the advantages and disadvantages of the types of fibers and where they are used.

Assignment/ Learning Activities:

List the factors involved in the choice of fabric finishes in interiors. Discuss factors such as:

personal tastes, cost, use of the room, desired effect, size and shape of the room, maintenance,

ease and cost of installation, decorative theme. Examine the texture, colour, scale, and line of

sample fabric to determine the effect created in a room.


Supplementary Material/ Suggested Reading:

i. Manufacturer‟s Details

ii. Engineering materials (Surendra Singh)

iii. Relevant I.S.Codes

iv. Building Construction (Mackay, 4 Volumes)


Lesson - 15: Upholstery Materials

Objective:

To identify the types of fabrics used as upholstery material in interiors and choosing between

various materials, styles and patterns, maintenance & care.

Structure:

15.1 Introduction

15.2 Fibre Content

15.3 Construction

15.4 Colour Fastness

15.5 Texture

15.6 Wearability and Functionality

15.7 Pattern

15.8 Upholstery Fabrics

15.8.1 Brocade

15.8.2 Brocatel

15.8.3 Damask

15.8.4 Cretonee

15.8.5 Chintz

15.8.6 Tapestry

15.8.7 Jacquard fabrics

15.8.8 Denim

15.8.9 Linen

15.8.10Speciality fabrics

15.8.11Plastic and leather

15.8.12Velvet

15.9 Inner Construction of Upholstered Furniture

15.1 Introduction

Upholstery fabric may be defined simply as a material used on furniture. The choice of material,

however, should never be haphazard. In a well-planned decor, the upholstery material attains

untold importance; its importance can never be overstressed. Your choice of material can

actually enhance the overall decor, or it can “ruin” it.

In choosing upholstery material, there are certain factors, or points, which you should consider

very carefully. Among these are such items as fibre content, construction, colourfastness, texture,

wearability, functionality, and pattern.


15.2 Fibre Content

Years ago all fabrics were of cotton, wool, or silk, or of one of the many bast fibres, that is,

fibres made from the stems of certain plants, such as hemp and jute. However, drastic changes

have taken place in the last 20 to 30 years. Cotton, called the king of fibres, remains the most

used of all fibres. Wool is still in great demand. Silk, once a widely used fibre for every kind of

fabric, has all but priced itself out of the consumer market. This does not mean that silk goods

are no longer available. Silk has retained its title as queen of fibres, but the price of silk prohibits

its use for any but the most luxurious of fabrics. It is used in those fabrics where its

characteristics - fineness, strength, and lustre - are highly desired by the consumer. Most

luxurious silk goods today are priced beyond the means of the average family.

The advent of the synthetic, or man-made, fibres has brought about the drastic changes just

mentioned. Rayon was first introduced to the consumer in the early thirties. It was developed as a

replacement for silk, and at times was erroneously called artificial silk, the term proved to be

wrong; rayon never achieved any resemblance to silk. But new uses were found for the fibre,

causing its importance to increase by leaps and bounds. Its price, quite comparable to that of

cotton, was the reason. Today, rayon is still unexcelled for many purpose, and it is used

extensively in all types of materials.

After rayon came acetate, nylon, Orlon, Dacron, Kodel, Arnel, Acrilan, and on, to a list of some

40 to 50 different fibres, each of which has characteristics that make it applicable to specific

uses. Acetate and nylon are perhaps the best known of the newer synthetics. Acetate gives a crisp

hand, or feel, to fabrics, a characteristic long desired for certain uses but previously unattainable

without special chemical finishes. Nylon, of course, is best know for its strength and elasticity.

Today, you will find fabrics made with just about every known synthetic. The synthetics are also

often used in blends with the natural fibres. As an example, a fabric made with wool and nylon

will be far stronger than the same fabric made only with wool. Other blends are also used. In the

years to come there will undoubtedly be countless other synthetics made available. Perhaps some

day the chemists and research organisations will develop a replacement for cotton.

15.3 Construction

All upholstery materials, excepting the leathers, imitation leathers, and plastics, are woven on

power looms. For that reason, the construction of the material becomes important. No matter

what fibres were used in making the material, the material is poor if it is not constructed

properly. Beware of any material that appears to be loosely woven; this is an indication of poor

wearing qualities. Fabrics with loose, straggly appearing yarns should be avoided. A well-

constructed fabric will always be firm and will always serve the purpose for which it was

intended.

15.4 Colour Fastness

Once a highly troublesome characteristic in fabrics, colourfastness is achieved today in

practically all of them. Methods of dyeing and printing have been improved to such an extent

that a fabric dyed and guaranteed colourfast will generally be just that. Here again, however, the

reliability of the dealer becomes important.


Colourfastness is essential in upholstery fabrics, especially where the furniture is exposed to

sunlight. When fastness is assured, the colour retains its brightness; the colour will not fade and

become dull.

15.5 Texture

Texture is very important today. The wide range of available textures in upholstery fabrics gives

the decorator the opportunity to achieve the desired effects in the decor. You can actually

perform what might be called miracles, simply by taking advantage of the possibilities offered by

fabric of the right texture. One point you must bear in mind though - the texture of the upholstery

material, as well as that of the drapery material, must agree with the mood and style of the room.

In other words, if you decorate with period furniture, the upholstery material must conform to the

same period. Although variety in texture is permissible, extremes must be avoided. Cottons are

popular with homely country styles and with Early American and simple French styles, Elegant

Georgian furnishings call for shinny fabrics, such as satins and brocades. Nubby, rough textures

go best with modern furniture.

15.6 Wearability and Functionality

Although colour and pattern often predominate over wearability and functionality, these last

qualities are extremely important. As was said previously, tightly woven fabrics always wear

better than loosely woven ones. Bear in mind also that flat fabrics, such as satin, brocatel, and

brocade, will not wear as well as frieze, a pile fabric with uncut loops, and other similar fabrics.

Nylon fabrics or fabrics containing nylon in proper percentage will generally outwear similar

fabrics made with other fibres.

Functionality is essential, that is, the fabric must be suitable for use as upholstery. You certainly

would not think of using broadcloth as upholstery; it just would not serve the purpose intended.

15.7 Pattern

The decision as to whether to use a pattern or to purchase upholstery fabric without a pattern

depends primarily on how much pattern is already used in the room. The rules to follow are

simple. If there are patterns in the rug or wall, there should not be any pattern the upholstery

material or in the draperies. Appropriate texture can be used to advantage in these instances, but

patterns should be avoided.

On the other hand, if the room appears to be dull or drab, it can be made interesting and colourful

through the use of patterned upholstery and drapery materials. In choosing a suitable pattern,

bear in mind that large patterns will tend to distract; it is much more appropriate to choose a

small pattern that will blend into the overall decor effectively without drawing too much

attention to itself. A large room can accommodate pattern design. In a small room it is usually

best to limit pattern design to one or, at the most, two areas, or to stay entirely with solid colours.

Small floral and fruit designs are popular for Early American decors; pastoral scenes, scrollwork

and floral designs are associated with French styles‟ stripes and leaf designs go with classical

decors.

15.8 Upholstery Fabrics

The following list of upholstery fabrics by no means complete, but it does include the more

important fabrics. There is a brief description for each.


15.8.1 Brocade.

The name brocade very likely comes from the Spanish Brocade, which is derived from the Latin

Brocade, which means “to figure”. The fabric is characterised by a compact background with

embossed or embroidered effects used in construction to make the motif or figure. Motifs may be

flowers, foliage, scrollwork, pastoral scenes, or other designs. Brocade is used extensively for

curtains, pillows, and upholstery.

15.8.2 Brocatel.

This fabric is recognised by its smooth

raised figure. True brocatel is a double

cloth made of silk and linen, but rayon

replaces silk in the present day

material. While classed as a flat fabric,

brocatel shows patterns which stand

out in “high” relief, a sort of blistered

effect.

15.8.3 Damask.

Another figure fabric, damask is made on the intricate Jacquard loom. It is one of the oldest and

most popular staple cloths found today. Made with all known fibres, it belongs to the same group

of fabrics as brocade, brocatel, and Jacquard. Elaborate designs are possible in this fabric.

Damask has a high lustre, as evidenced by the fabric when used for tablecloths and napkins. It is

very durable and its price varies over as great a range as any fabric possibly could, from cheap to

very costly.

15.8.4 Cretonee.

This is another staple cloth always in demand for many uses. As with damask, the price and

quality vary considerably. The background of cretonne is often such that the entire surface is

covered with design. Much foreign

matter, such as pieces of leaves and

twigs, is seen in this fabric when it

is made of cotton, but this matter is

not considered detrimental to the

cloth; in fact, it seems to add to the

appearance and tone of the finished

goods. Printed cretonne has no

lustre. The fabric is strong, stout,

and substantial, and it provides

good wear. All types of designs are

used.

15.8.5 Chintz.

Chintz is a glazed fabric, generally made of cotton, often printed with gay figures and large floral

designs. There are several types of glaze: wax, starch, and resin. Wax and starch glazes will wash

out in laundering. Raisin glaze is very durable and will withstand laundering and cleaning.


15.8.6 Tapestry.

This is a picture material, woven tightly or loosely; the design is part of the actual fabric rather

than being embroidered onto the cloth. Tapestry may be hand-woven or woven on power looms.

It is extremely popular for use with almost all period furnishings.

15.8.7 Jacquard fabrics

These are any of numerous fabrics woven on the Jacquard loom. Jacquard weaving produces

elaborate designs. It is used for numerous purposes.

15.8.8 Denim.

This is another highly staple cloth which is rugged and serviceable. It is recognised by a left-

hand twill on the face of the cloth. Although it is the most important fabric in the work clothes

group, denim is also popular in the upholstery and furniture trades. It is often used on modern

furniture.

15.8.9 Linen.

Real linen is made from flax, a fine, soft bast fibre. Today, however, many other fabrics are

given a simulated linen finish. On simulated linen the reflection is given by the finish, which is

not permanent. In real linen, light is reflected by the natural surface. Real linen is an absorbent

material; it gives off moisture very rapidly by evaporation, making it a cool fabric.

15.8.10 Speciality fabrics.

A speciality fabric is any of a number of fabrics specially designed and woven for the upholstery

and furniture trades.

15.8.11 Plastic and leather.

Leather on furniture has always suggested luxury. It

can be easily washed, it wears well, and hair and lint

do not stick to it. Today you can have the luxurious

appearance of leather with the same ease of

maintenance by using plastic. Plastic is available in a

larger range of colours and if it is backed with fabric it

sometimes outwears leather. Leather or plastic is

specially good where a masculine appearance is

desired.


15.8.12 Velvet

Velvet has been popular from time to time, but it is

seldom used today in either period or modern decors

because it is not practical. It looks soiled when rubbed

the wrong way. It attracts lint and dust and is difficult to

keep clean.

15.9 Inner Construction of Upholstered Furniture

An upholstered chair can only be

as good as its inner construction,

regardless of how beautifully it

is shaped and covered. The inner

construction consists of frame,

springs, and filling. The best

frames are made of elm, hard

maple, ash, or birch. These

woods are strong and will take

glue well. On the best furniture,

all joints are secured by dowels,

reinforced with hardwood corner

blocks that are screwed and

glued into position. The base that

supports the springs may be

made of cloth, steel, or wood

slats. The cloth webbing is of

heavy burlap strips, about four

inches wide, attached firmly to

the wood framework and passing

alternately over and under strips

running in the other direction.

This is called Italian webbing.

When steel is used it is in the

form of rods, or suspension bars.

The bottoms of the springs should be firmly interlocked with the rods so that they cannot move

or slide horizontally. Cloth webbing or steel rods are superior to wood slats for the support of

springs.The coiled springs should be of enamelled tempered steel, and they should be tied with

strong hemp twine to the adjacent springs and to the frame. A layer of heavy canvas or burlap

goes over the springs and the filling, and stuffing goes over that layer. The stuffing in cheap

upholstered furniture is often shredded wood or even old rags or straw, Curled horse hair,

feathers and down, or rubberised hair make fine, resilient stuffing and are usually covered with a

layer of thick cotton or foam rubber. Foam rubber is replacing many of the materials

conventionally used in stuffing and is very often used in backs, over the arms and in the seat

cushions. In lightweight furniture, foam rubber is sometimes substituted for the filling and a

simpler structure of metal or wood is substituted for the webbing and springs.


Summary:

Upholstery fabric may be defined simply as a material used on furniture. The choice of material,

however, should never be haphazard. In a well-planned decor, the upholstery material attains

untold importance; its importance can never be overstressed. Your choice of material can

actually enhance the overall decor, or it can “ruin” it.

Various types of fabrics used in interiors. such as: Tapestry and other woven and non-woven

materials.Properties, qualities of the various materials used as upholstery fabric.

Upholstery material include the requirements of different income groups – the colour, design,

texture and pattern of the fabric, the cost and construction of the various materials.Cleaning and

maintenance of upholstery fabrics.

Revision points:

Upholstery material include the requirements of different income groups – the colour, design,

texture and pattern of the fabric, the cost and construction of the various materials.Cleaning and

maintenance of upholstery fabrics.

Cushioning Materials Construction:

Webbing – use of Cardboard or perforated plywood, Springs –Tying of springs determines the

shape of the seat., Burlap – used to cover springs, Edge Rolls – to provide padding in layers for

extra. This could be hair, moss, tow or PU foam etc. and many other points which gives us

detailed explanation about coushning materials.

Key words:

Upholstered fabric: - Upholstered fabric may be defined simply as a material used on furniture.

In choosing upholstery material, there are certain factors, or points, which you should consider

very carefully. Among these are such items as fibre content, construction, colourfastness, texture,

wear ability, functionality, and pattern.

Tapestry. This is a picture material, woven tightly or loosely; the design is part of the actual

fabric rather than being embroidered onto the cloth. Tapestry may be hand-woven or woven on

power looms. It is extremely popular for use with almost all period furnishings.

In text question:

i. What is the importance of upholstery fabrics in any interior space?

ii. What points would you keep in mind while choosing an upholstery material? Explain in

detail.

iii. Discuss any five types of upholstery materials in detail.

iv. With the help of a sketch explain the inner construction of upholstered furniture.

Terminal exercise:

Students have to do a detailed market survey of the upholstery materials available in the market

today.


Assignment/ learning activities:

Prepare a detailed report highlighting the cost, materials, and availability of these products in

your area.

Supplementary material/ suggested reading:

i. Manufacturer‟s Details

ii. Engineering materials (Surendra Singh)

iii. Relevant I.S.Codes

iv. Building Construction (Mackay, 4 Volumes)


Unit – IV

Accessories

Lesson -16: Accessories

Lesson -17: Wall Accessories

Lesson -18: Sculpture and Table Ornaments

Lesson -19: Window Treatments

Lesson -20: Types of Window Treatments

Lesson -21: Window Treatment Hardware


Lesson - 16: Accessories

Objective:

To increase awareness of the use of accessories in creative expression and individuality.


16.1 Arranging Accessories

16.0 Introduction

Just as jewellery, a decorative handbag or belt, and other accessories can enhance the beauty of a

suit or dress, so too can the accessories in room enhance the decor. The accessories you put into

a room can do more to express you than the furniture does Great care must be exercised,

however, to prevent accessories from becoming excessories. Do not overdo it. You would not

want to appear overdressed and you certainly do not want the rooms in your home to be

overdressed. Remember the middle ground between the extremes of too much and too little.

Accessories are the finishing touches that

express the personality of the people who live

in the home and that enhance the beauty and

character of the decor. As such they must be

appropriate to the decor. Even in selecting the

smallest item, such as an ashtray, you must

consider the appropriateness of the colour,

design, and texture of the article.

In choosing accessories you can spend as much

as you want to or as little as you have to.

Stores, from dime stores to the finest gift and

antique shops, are filled with items that can

enhance all types of decors, if selected

carefully. The colours, textures, and period or

national style of even the smallest accessory

should agree with (although it need not match)

the colours, textures, and styles of the other

accessories and the overall decor.

Accessories can usually be sharper in colour

than the larger areas in a room. The strongest

colours should ordinarily be on small accessories. But too many small accessories of different

strong colours will make a room look spotty. A small area of strong colour balances a larger

area of light or dull colour.


The orient has long been a source of inspiration to designers. Simple oriental styles are never

“dated” and there is some element characteristic of the orient that you can adopt to every type of

decor. You might choose a bamboo window shade, a lantern -like sphere to light the hall or

bedroom, a lacquered commode for the living room, a simulated jade vase, a Chinese figurine, an

Oriental miniature scene, or a Ming tree. A stack of square thick pillows to scatter around the

floor for seating, Oriental style, makes an interesting decoration in a modern living room or

recreation room. A touch or two of the Orient gives zest and flavour to an otherwise drab room.

16.1 Arranging Accessories

Furniture arrangement is usually limited by the

proportions and space available in a room,

especially in today‟s smaller homes. The

arrangement of accessories, however, can be a

challenge to your imagination and sense of

design.

Formal balance was the rule in most rooms in

the past. Formal balance is the precise

equalisation of lines and areas. Matching lamps

on matching small tables on each side of a sofa provide a good example of formal balance. It

was customary in the past to hang a picture or mirror over a fireplace and place a fairly low

object in the centre of the mantel. Identical hurricane lamps or candles would then be placed on

the two ends of the mantel. Such formal balance has a stilted and uncomfortable appearance.

Today, whether decorating in a period or

modern style, informal balance is often

preferred. Instead of mirrors being

centred over dressers, a tall mirror may

be placed to the left of centre. A lamp,

large bowl, or vase of flowers, or a

hanging light fixture toward the other

side, gives informal balance. There is still

a feeling of balance because the objects

have the appearance of being about equal

in weight.

Informal balance is visual balance or balance of areas according to visual weight. A figurine

placed to each side of a bowl of flowers would constitute formal balance. But if the bowl of

flowers was placed off centre and the figurines paired next to it, one a little father back then the

other, you would have informal balance. A bright-coloured small balances a dull or light

coloured larger object. Two small objects balance one larger one. If the smaller objects appear

lighter in visual weight than the larger one, place them farther away from the centre and they

may then appear to balance.

Think of the centre of a given area as being the fulcrum of a pair of scales on which weights

must be distributed for balance. Think of balance in terms of equalising visual weights rather

than of matching objects of the same size or kind.


Lesson - 17: Wall Accessories

Objectives:

Pictures are the most popular form of wall decoration. A simple picture of a bowl of fruit or

flowers might be pretty enough, but there are likely to be many other subjects that will show

more imagination and contribute more effectively to the decor of a room.

Structure:

17.1 Pictures

17.2 Framing pictures

17.3 Other types of pictures

17.4 Arranging and Hanging Pictures

17.5 Wall Mirrors

17.6 Sculptured Reliefs

17.7 Wall shelves

17.8 Wall and shelf clocks

Introduction

Pictures are the most popular form of wall decoration. They can and often do establish the mood

or theme of a room. It would be to your advantage to make at least a brief study of art

appreciation in order to know something of artists past and present and what they were or are

trying to show in their paintings. Then you will be better able to select, from the many paintings

you might like, the one that best expresses the feeling that you want to create in a room.

17.1 Pictures

A simple picture of a bowl of fruit or flowers might be

pretty enough, but there are likely to be many other

subjects that will show more imagination and contribute

more effectively to the decor of a room. When you think

of Early American rooms you associate them with

historical events, such as the landing of the Pilgrims,

their activities, and their struggle for survival. There are

pictures that convey these thoughts and establish the

chronological period on which your decor is based. A

classical decor is enhanced by scenes symbolic of

ancient Greece and the Roman Empire or scenes of the

periods during which the classical styles flourished in

Europe and the United States. The popular Louis XV

and French Provincial styles are emphasised by romantic

scenes that suggest gay court file, powdered wigs, and

the elaborate coiffures and gowns of the period.


Decor featuring late Colonial and Federal styles are enhanced by

patriotic scenes showing such events as the signing of the

Declaration of Independence, or depicting victories in the battle

for independence. Currier and Ives paints are delightful in any

informal, traditional decor and can be used for attractive

groupings. Audubon bird prints or other pictures of wildlife, or

even pictures of single flowers, make pleasing arrangements in

any room, depending on how they are framed and arranged.

For a modern room, abstracts or primitives, or sophisticated

scenes by artists past or present, are desirable. Reproductions of

paintings by Dali, Picasso, Dufy, or Kandisky might suit your

taste, or you might like the sophistication of the paintings of

ballet dancers by Degas or of Paris night life by Toulouse-

Lautrec.

Scenes of the western frontier by Frederick

Remington are at home in the recreation room or

den, while landscapes and water scenes can be

used in the living room, bedroom, or dining room.

Most religious pictures are more appropriate in

the bedroom than in living room or dining room.

Ships at sea, with the ship featured, are

considered more masculine than are plain

seascapes. Flowers are particularly feminine. Of

course, pictures that are neither heavily masculine

nor frivolously feminine are preferred in the

living room. A sea painting is in good taste in any

room and it will give an outdoor feeling and make

a room seem larger than it is.

Anyone who possibly can afford it should own at least one original painting. It is usually

possible to get a good painting at a reasonable price by buying directly from the artists. Visit

exhibits and artists studios and make contacts with recognised art schools. But if you cannot buy

an original, buy good-quality reproductions, in colour, of paintings by outstanding artists. Such

reproductions are sold in art stores, art supply stores, department stores, and large museums.

These fine art reproductions are not the same as calendar art, photographs, or commercial

illustrations.

Remember that outdoor scenes that show deep space will make a room seem more spacious than

will a still life or portrait. Family photographs and religious pictures belong in the bedroom, not

in the living room. However, paintings of members of the family or of pets are appropriate in the

bedroom, dining room, or living room.

A picture should help to carry out the colour scene of a room. Any strong colour in a picture

should be duplicated by an area of the colour somewhere in the room. For example, a painting of

the sea may have large areas of blue and highlights of reflected bright yellow. A large area of the

same blue on a chair or drapery, and another accessory of the bright yellow, will help to unify the

room and pull all of the elements together.


17.2 Framing pictures

The subject matter of the picture should be in harmony with the period style and colour scheme

in a room, and the frame should harmonise with the room and the picture. A plain wood frame

finished to match the wood in the room or painted to harmonise with the colours is always in

good taste. Carved, gilded frames should be used only in elaborate Georgian or other formal

rooms; they should never be used in modern or country-style decor. Leather frames are popular.

Though they are usually quite informal and masculine, they can be finished in very refined style.

Lacy filigreed frames are very feminine. For an ultramodern effect, pictures can be hung with

glass in front of them, without frames. Special brackets can be purchased at art supply stores for

this purpose.

An antiqued wood finish is achieved by staining the wood the desired colour, then going over it

with white lead paste or oil paint, working white into the grain and wiping it off quickly. A frame

finished this way is ideal for scenes of the west, most modern pictures, country scenes, and

pictures of animals, and it is suited to any informal decor, modern or traditional. A suitable

picture in an Antiqued wood frame is ideal in a den, recreation room, or a boy‟s bedroom.

Water colours, pastels, and charcoal, pencil, and ink drawings are framed with a border formed

by a mat which goes between the picture and the glass in the frame. The mat keeps the picture

from pressing against the glass. Mat board is available with various surface textures, and if it

may be any colour that harmonises with the picture and the room. White, off white and very

light colours are usually preferred. The mat may be narrow or it may be wide to give

prominence to a small picture. The bottom should be a little wider than the top or sides.

Etchings and other types of prints are usually framed with mats too. Certain definitions should be

offered here to enable you to understand the various names of prints.

An etching is a print made from a plate, usually

of steel, which is engraved by burning with an

acid into all the areas that are not to be printed.

A lithograph or litho, is made from a smooth

sheet of stone on which the drawing to be

reproduced is done with a greasy substance. The

impression is made from the greasy areas only,

because the ink is absorbed by the untouched

areas. Mechanical printing methods are often

erroneously called lithography.

Block prints are impressions from wood, or

sometimes from linoleum block, on which the

areas that are not be reproduced are cut and

carved out, either by hand or mechanically.

In the home original oil paintings never have mats or glass over them, but reproductions are

sometimes covered with glass for protection. You can make a reproduction of an oil painting

look like an original by varnishing it and framing it without glass. First mount the print on stiff

cardboard with rubber cement. Use a board that is larger than the print, trimming it after the print

is in place. Use a good clear varnish, preferably a quick drying type that does not contain a lot of

oil to stain the paper. White damer or clear damar, is good and is available in art supply and


hardware stores. The varnish should be applied in two thin coats. To give texture to the surface,

you can place a sheet of window screen or net or any textured cloth such as burlap over the wet

surface and lift it up quickly. Do not move it on the surface.

17.3 Other types of pictures

"Pictures" to be considered as accessories are not limited to

scenes, still life and portraits. An interesting collection of

such things as leaves, butterflies, or coins can be mounted and

displayed like pictures. Such items can often express your

personality better than conventional pictures. Record album

covers framed or unframed, a cork bulletin board for clipping

and snapshots, school pennants, or colourful travel posters are

often used with striking effectiveness in recreation rooms or

teenagers‟ rooms.

Enlargements of gag cartoons or caricatures that strike a note of appropriateness are ideal in the

recreation room. Any photo shop can make them for you. Fairy tale scenes can sometimes be

taken right out of children‟s‟ books and enlarged for the nursery or a child‟s room. Farmed or

mounted maps and enlarge copies of documents such as the Declaration of Independence make

original and distinctive decoration in place of more conventional “Pictures”. `Either a map or a

document should have some relation to the decor of the room. Such documents as personal

diplomas or legal certificates or testimonials may be hung in the bedroom, home office, or den,

in a library or study, and sometimes in the dinning room. But personal documents many be

considered to be in poor taste in the living room.

Do not make the mistake of displaying stuffed, mounted animals or fish, or parts of animals such

as head or skins. These trophies may be highly prized by the man of the house, but they are

extremely distasteful to animal lovers and also to people who dislike being surrounded by dead

creatures. If they must be shown at all, they should be limited to a den that is the exclusive

territory of their proud possessor.

17.4 Arranging and Hanging Pictures

Pictures should always be as flat against the wall as possible and the wires that hold them up

should be concealed.

There are many ways to arrange pictures to show them off and to make them contribute to the

overall effect in a room. Pictures that are the same size and related in subject matter can be

placed in groups, either vertically or horizontally. It is not a good idea to place pictures in "step"

arrangements, diagonally, expect on a wall next to a stair case. When pictures are used in

groups, the frames should either match or harmonise with each other. A vertical arrangement of

pictures can be used in a space that is higher than its width and a horizontal arrangement can be

used in a long area, such as the wall behind a sofa. A picture or a group of pictures can be used

over a low piece of furniture to balance a higher piece of furniture in the same room, usually on

the opposite wall.


When they are used singly, different types of pictures in different kinds of frames can be used in

the same room. One large picture on the wall and two or three smaller ones on another wall make

a good, balanced arrangement. But if you use small pictures near a large one they will detract

from the large one. A picture hung alone, or a row of pictures placed horizontally, should be at

the eye level of an adult standing in the room.

When walls are patterned, the subject matter of

a picture becomes particularly important. A

lot of fine detail in the picture will conflict

with the patterned background. Subjects that

have large areas of one colour, such as pictures

featuring water or sky, are always good. If

there is considerable detail, as there usually is

in scenes that include people, flowers or fruit,

a wide mat with a smooth or textured surface

in a solid colour will usually provide adequate

separation between the picture and the

background. The very wide, protruding

frames, called shadow-box frames, that were

so popular a few years ago do not serve th same purpose as a wide mat or a wide, almost flat

frame; nor are they considered to be in good taste today.

If you have a long narrow piece of furniture in a room, as, for example, a buffet or sideboard in a

dinning room, and you want to hang two or three pictures vertically over it, you do not have to

centre them. You can hang them off centre, near one end of the piece of furniture. To achieve

formal balance you would then hang a matching row over the other end and place something in

the centre of the buffet. However, as mentioned previously, formal balance looks stilted, a tall

lamp, or a statue or vase of flowers, if proportioned correctly, can balance your vertical row of

pictures informally.

17.5 Wall Mirrors

Mirrors can make a room look large and they are also a very useful

accessory if placed conveniently. Mirrors can be hung unframed, with

clear Lucite frames, or with wood picture frames in modern rooms. With

period styles the frames should be similar to those that were actually

used with the furniture during the period when it was designed.

Mirrors should be large enough to be of real use. a

large mirror placed at one side of a narrow room or

hallway will add width, placed over a small piece of

furniture, it will reflect and balance a larger piece on the other side of the

room. Mirrors should not be used as substitutes for pictures. They have a

function to perform and should be located conveniently for use, except for

mirror walls, which are primarily decorative. A hall way entering into the

main rooms of the house is one ideal place for a mirror. A mirror located

near the main doorway enables you to catch a glimpse of yourself just as you

enter or leave the house and also shows consideration for your guest.


17.6 Sculptured Reliefs

A sculptured relief is something between a picture and a

statue. It is a figure or sculptured plaque that hangs on the

wall and may be made of wood, stone, metal, or any other

solid material. Smaller, simplified birds and fish, and

simulated musical instruments of wood, are popular in

modern rooms, individually and in groups of two or three.

17.7 Wall Shelves

Wall shelves built into the wall have

become increasingly popular since the

time many homeowners started adding

wood or other types of panelling to

walls. It is a simple matter to make

provision for them when walls are

panelled. The shelves should

preferably be adjustable, that is, they

should be separate. Metal tracks

should be built into each side of the

shelf case so that the shelves can be

raised or lowered. Shelves in room

dividers and various types of cabinet

book cases are available.

Books should, of course, be chosen for their content and not for their decorative values. They

can, however, be arranged to form interesting patterns of colour and size. For a balanced

appearance it is usually best to place the tallest book on the low shelves and to place together

books of one colour or style, such as volumes that comprise a set.

Avoid crowding shelves. If possible, leave an empty space or place a figure or plant on a shelf

among the books.

If you have a secretary, a room divider, or built-in bookcase and you have few books to put on

the shelves, you can put objects on them instead of, or along with, the books.

17.8 Walls and Shelf Clocks

Just as books should be chosen for their content, wall clocks should be selected to show the time.

They are designed to suit various types of decorating schemes and they should, when used in

homes, be attractive accessories. But the design of a clock should never detract from its primary

function as a timepiece.


Lesson - 18: Sculpture and Table Ornaments

Objective:

To understand the basic use of sculptures and table ornaments in decorating.


18.1 Lamps

18.2 Other accessories

18.3 Birds and fish

18.4 Bedspreads

18.0 Introduction

Figure made of stone, marble, wood, metal, glass, or ceramic clay are useful in the decorating

plan. Like all other items in the room, they should be in keeping with the overall decor, and they

should usually be from 8 to 18 inches high to be in proportion to the room.

Anyone who can, should buy original sculpture. Exhibits and art schools are good sources of

supply, especially of pieces for modern interiors. Mobile sculpture, which is comprised of light,

small forms that are delicately balanced on wire, hang freely, and move almost continuously, are

in good taste in ultramodern rooms. wire sculptures, which may stand free or hang on a wall,

can have merit, but they must appear balanced and in good proportion to the room. for period

statues you can often find good pieces in gift or antique shops.

Reproductions of fine sculpture are available and can be ordered through art museums or art

supply stores. Ask an art dealer in your area to let you see an illustrated catalogue descriptions

of the pieces usually tell you about the dimensions, material as well as the reproductions

available. The reproductions are scaled to be in good proportion to the rooms in a home.

Wood and stone sculpture should be compact and solid without protruding parts that look as

though they would break off easily. A sculptured figure, for example, should either be without

arms or should have arms attached to, or close to, the body. Sculpture that is formed in mould,

such as bronze sculpture, or modelled by hand, such as clay or ceramic, can have softer, more

rounded and fluid lines that stone, which must be chipped from a solid block of the material used

and the subject of the sculpture must be adaptable to the material. Delicate textures such as

chiffon and delicate subjects such as flowers may be interpreted effectively in ceramic but have

no place in stone sculpture.

Figurines less than 5 inches high are simply knick-knacks. Any object that cannot be identified

from any part of the room is usually unsatisfactory as an accessory. Sometimes a group of three

or five, knick-knacks related in subject can be used on a shelf in a fairy small, informal room, but

as a rule it is better to concentrate on one or perhaps two fine, well-proportioned pieces.


An important piece of sculpture piece of sculpture should be given a prominent position in the

room. Ideally it should stand on its own, perfectly plain pedestal, but it can be placed on top of

piece of furniture that is not too small for it. Less significant pieces such as figurines can stand

on shelves or end tables.

18.1 Lamps

Lighting is a very important element in the overall

decor. Lamps are both fixtures to give light and

decorative accessories, but the decorative element

should never defeat the efficiency of the lamps. The

wall candles, which are often used in traditional

decors, are usually purely decorative, but they can

be burned on special occasions. Sometimes they are

electrified with small, flame shaped bulbs, often

with an appropriately styled shade over them. The

desk or table lamp is based on a Directoire style and

would be suitable in a Colonial or any traditional

room.

Table lamps are more popular today than floor

lamps, but the floor lamp has won favour in recent years. Floor-to-ceiling shafts without the

base, as well as various styles of shades, are available. The lights can be turned in any direction,

for reading, for indirect lighting, or for spotlighting an important piece of furniture or an

accessory.

A classical-styled modern lamp should be at least 28 inches high. Many table lamps with non-

adjustable tops are too low to be of any practical value and too small in proportion to most

rooms. Lamp shades today are usually washable. They should never be used with the cellophane

wrappers they come in.

If you want an authentic piece of Early American, you should like the fine copies of hurricane

lamps. These lamps throw beautiful and colourful flecks of light.

18.2 Other Accessories

Colourful pillows are used liberally in modern rooms. The

colours and textures should be consistent with the rest of

the room. Sometimes pillows in bright colours are scattered

about a sofa to provide the colour accents in a room.

Although pillows, which are seldom used for anything but

decoration, are a modern innovation, they can also be used

in traditional rooms. Pillows with sheeny silk covers and

sometimes striped covers go with elegant, formal decors.

Corduroy, gabardine, and other coarse fabrics in solid

colours are better with modern furniture. Satin or velvet

pillows with flowers or sentimental scenes painted on them

are gaudy and have no place in today‟s home Lacy doilies

should not be used either on chair arms and backs or on

table tops.


Plants make attractive accessories. A low plant, such as the popular velvety-leafed African

violets, are good on low tables such as cocktail tables. Hanging ivy plants look good on wall

shelves. Large-leafed plants, such as the exotic rubber-tree plant, are ideal in a large vase or pot

on the floor in a corner. Next to a piece of furniture or near a window. Be sure that your plants

are chosen to be placed where they will receive the amount of light they need. Any plant holder

can be attractive in design and colour; but it should look like a plant holder and not like a swan

or an animal. Basket holders lined with metal, glass, or pottery are attractive in informal rooms.

Plastic containers on tripod bases are also modern, and colourful. Copper, wood, or milk glass

containers are good with early American decors. Silver and glass should be chosen for more

formal rooms. Brass boxes make good plant holders in any decor.

Chinese porcelains or good copies, and copper or decorated plates, are often displayed on shelves

over the mantel in traditional and early American rooms, but this should not be overdone. A few

choice pieces can be effective; a lot of them will attract too much attention. Translucent glass can

be very pleasing and eye-catching when displayed on glass shelves in front of a window.

Cigarette holders and ash trays are available in a wide variety of styles. They may come in

matched sets of crystal, copper and other metals, or ceramic, or of many other materials. The

Hyalyn Porcelain Company of Hickory, North Carolina, makes smart sets in porcelain. Choose

the style and material that will go best with your decorating plan. The Fostoria Glass Company

makes a set in lead glass that goes beautifully with Early American. There are also baroque

styles in silver, styles made with ceramic tile, and Oriental styles with lacquer bases. The

Ronsom Corporation and other manufactures make table lighters of various material and styles.

Decorative silver ones are ideal for formal rooms, especially if silver or crystal items are used

elsewhere in the room. Very plain style or dull and shiny patterned surfaces are better in modern

rooms. The colour of the metal should harmonise with the decor. Ash trays should be deep

enough to prevent accidents with lighted cigarette and they should be designed to look like ash

trays. Animals forms or hollow figurines are not in good taste. Leaf-shaped or plain rounded ash

trays are excellent and many of them, depending on the colour and materials, are good in any

decor.

There are so many varieties of miscellaneous accessories from pillows to ash trays that it would

be impossible to illustrate and describe even representative assortment of them, but at this point

you should have a good idea of what type of decoration and styling to look for, for the decorating

plan you want to follow.

Candy dishes and fruit bowls, tall pitchers and other serving pieces, and vases can be good

accessory items. They should be harmonious with the decor both in colour and in style, whether

they are in use or just displayed to decorate the room. Coffee and tea sets and cocktail mixers

and sets are available in numerous styles; if these are well designed and are consistent with the

decor, they make ideal cocktail table or buffet decorations.


18.3 Birds and Fish

When you are planning the accessories for your

decor, do not overlook the decorative value of

colourful tropical fish or birds. If you like an outdoor

atmosphere in your home, they can contribute more

than pictures or anything else. Of course they do not

harmonise with a very elegant, formal room, but in

any informal room they can be a charming centre of

attention. Bird cages are available in many styles and

all of them blend with decors that include a straw

accessory or modern, rough textures, such as grass-

textures wallpaper. Colourful canaries and parakeets

are amusing as well as attractive.

Plain square tanks, or aquariums of clear glass, are

best for fish. The tiny round bowl that are often used

for goldfish are not attractive as accessories; more

important, they are not satisfactory for their purpose.

A tank of colourful fish and accessory items such as

seaweed, stone or glass bridges, multicoloured gravel

or rocks, and possibly a few shells, and with a light

over or behind it, lends itself beautifully to a modern

room. Aquariums should be equipped with filters and

thermostats. Both fish and birds require some care,

but with modern equipment, upkeep is no problem.

18.4 Bedspreads

All that has been said in reference to accessories

applies to bedrooms. A bedspread is on accessory that

is used only in the bedroom.

Ruffle-flounced spreads should be used only in Early

American and traditional decors. The colours patterns,

and fabrics should be in accord with the decorative

style of the room. Straight sides and little or no design

are in order in modern rooms. Matched bedspreads

and draperies are available and are satisfactory if the

colours are not too strong and if there is not too much

pattern. A bed is a large piece of furniture and a

spread that is too ornate will make it look bigger.


Summary:

The unit tells us how to apply design principles to create a pleasing environment, To develop an

appreciation for personal and cultural aspects in designing an interior, To make informed

consumer decisions when selecting materials and equipment for interior development, To create

an awareness of accessories and how they personalize an interior, To achieve a pleasing and safe

interior by applying the design fundamentals, To strengthen consumer knowledge and

understanding of accessories.

Revision points:

The guidelines in hanging pictures. Consider Hanging pictures at eye level, Balancing the

proportions of picture, wall space, and furniture, Complementing the wall colour, texture, Taking

advantage of lighting, Grouping the pictures, Using appropriate hardware.

List of accessories: Plants and floral arrangements, Pictures and wall hangings, Book shelves and

books, Ornaments, Collections, Candles etc.

Key words:

Pictures:- Pictures are the most popular form of wall decoration. They can and often do establish

the mood or theme of a room.

Informal balance: - Informal balance is visual balance or balance of areas according to visual

weight

Formal balance: -Formal balance is the precise equalisation of lines and areas.A figurine placed

to each side of a bowl of flowers would constitute formal balance.

knick-knacks:- Figurines less than 5 inches high are simply knick-knacks.

Intext questions:

1. What is the role of accessories in the overall décor of a room?

2. What points would you keep in mind while choosing accessories for a room?

3. Discuss in detail the various types of wall accessories.

4. How important is the frame in a picture? Discuss

5. Write short notes on the following:

Sculptures

Informal balance

Birds and fish as accessories

Bedspreads

Plants


Terminal exercise

Students have to categorize accessories as decorative or functional or both. And have to visit

stores or show rooms to view the use of different accessories and they will examine accessories

for quality and function. And compare price and quality.

Assignment/ learning activities

Students will examine accessories for quality and function and compare price and quality.

Visit stores to look at the different accessories available and their quality and have to prepare a

complete report of their related market survey and Students have to prepare a collage showing

different accessories with different effects like paintings with different hanging style, different

size sculptures etc.

Supplementary material / suggested reading

1. Engineering materials by Surendra Singh



4. Trade magazines


Lesson – 19: Window Treatments

Objective:

To identify and evaluate the functions of windows in interiors.

Structure:

19.1 Introduction

19.2 History

19.3 Fabric

19.4 Covering a Window

19.5 Selection Criteria for Window Treatments

19.1 Introduction

Creative window treatments are a key element in decorating any home. Stylishly dressed

windows make a room seem complete and add the finishing touch to the overall decor. Some

treatments are dramatic and become the focal point of a room while others are subtle and

complement existing decorating features. With a century of creative ideas as reference, the

options for today‟s window treatments seem limitless.

Window treatments serve various functions in addition to their aesthetic qualities. They can

control light, affect air circulation, insulate against weather and noise and provide privacy. They

can also enhance a beautiful view or camouflage an unpleasant one. When selecting a window

treatment, carefully consider which function(s) should be the first priority.

19.2 History

New building construction and the remodelling of older buildings keep the demand and interest

for updated and practical window treatments in the forefront of interior design. Historically,

fabric window treatments meant pinch-pleated draperies. Then four-inch rod pocket curtains

came into style and were soon followed by more options in decorative rods and poles. This trend

led to an emphasis on tab-top curtain treatments. Now the trend is turning toward shirred curtains

and scarves. Unique window treatments are now possible simply by selecting different

combinations of curtains, top treatments and accessories.

Blinds and shades have also changed over the years. Venetian blinds and Austrian shades of the

1950's gave way to Roman and fabric shades. Puffy balloon and cloud shades were replaced with

mini, vertical and micro blinds. Today, horizontal two-inch wood blinds are enjoying a revival.

Many designers now use a combination of blinds and shades with fabrics, especially top

treatments.


19.3 Fabric

The end of the 20th century features window treatments that are soft and layered with sheer

curtains and scarves often used to achieve this look. Interesting colour, texture and pattern

combinations show up in both casual and formal styles. Many choices in fabrics are available;

including printed formal and plaid sheers, embroidered and crushed voiles, fancy batistes and a

variety of laces. These fabrics are often layered with sheer curtain over sheer curtain or tiered

with more classic forms, such as crisp panels or non-fabric treatments.

Pattern choices in fabrics are limitless. Popular themes found in fabric motifs include:

Floral and fruit patterns with an occasional butterfly.

Classical and Renaissance motifs, softened by draping the fabric and accenting with

scarves, trims and accessories.

Prehistory or ancient history motifs include fossils, engravings and ancient drawings.

Classic stripes, simple plaids and tone-on-tone solids in interesting textures that mix well

with other fabrics and add dimension to the soft looks.

Polyester and cotton are dominant fibres used in window fabrics. Sheer curtains are most often

100% polyester with special chemical treatments sometimes used to create iridescent or soft faux

suede finishes. Both 100% cotton fabric and blends combining cotton with polyester, linen, silk,

or rayon are popular choices. Cotton finishes vary widely and may include a sateen finish,

brushed for a soft hand, and dramatically woven into damasks or brocades. Other options, such

as wool and plush velvets, are seasonal favourites or used for special areas.

19.4 Covering a Window:

There are a number of reasons why a window needs to be covered. Some of these are follows:

Aesthetics: one of the major reasons for covering a window is to add to the beauty of the

room. Window coverings can form the main focal point of a room‟s decorating scheme.

Privacy: though windows are a very good source of natural light, and these also serve as

a means of providing an outside view from a room, they also prove to be an obstacle


when privacy is desired in a room. Window coverings help us to overcome this problem

by providing us with a way of covering the window when required.

Energy Conservation: these help us to conserve energy by cutting down on the amount

of heat or cold coming through the window, in summers and winters.

Light Control: using window coverings can control the amount of natural light coming in

through a window. Depending on the material of the window covering you can regulate

the entrance as well as exit of light through a window.

19.5 Selection Criteria for Window Treatments

The following points should be kept in mind while selecting a window covering for a room:

Fenestration design, arrangement and proportioning of windows: Placement of

windows on the interior walls of room often impacts type of covering used. The type of

window covering used is affected by the location of air vents, furniture placement, and

the need to operate windows. View of windows from street often dictates the selection.

Windows should offer continuity and similarity in both style and colour.

Quantity of light: the selection of the window covering will depend a great deal on the

amount of light desired in a room. The quantity of light in a room is governed by the

following factors:

o Degree of light or glare penetrating room: this is effected by the size and shape of

the window as well as its location.

o Direction or Orientation: the amount of light entering a room due to its orientation

according to the sun.

o Exterior shade – trees or overhang: whether a window is getting any exterior shade

because of a tree or overhanging structure also effects the amount of light coming in

through a window.

o How room is used: the amount of light required from a window will also depend on

the usage of the room. If the room is to be used as a study or playroom it will require

more light as compared to when it is to be used as a bedroom.

Structural Factors: by structural factors we mean the structural composition of the

window. The structure of a window can effect the choice of a window covering in the

following ways:

o The direction of the operable window has a big impact on the type of window

coverings that can be used.

o The operating mechanism can also be a problem, especially for inside mount blinds.

o Problem windows include:

Casement

French doors, sliding doors

Bays and bows, architectural shapes

Function: Functional considerations for the selection of a window covering include:


o Degree of privacy required: this is a major factor effecting the window covering

selection, if little or no privacy is required then you can go in for a very light and

transparent window covering material. If the privacy is required in the evenings only

then again you don‟t have to go in for a very heavy weight material. But if on the

other hand total privacy is needed the choice of window covering will have to reflect

this. Sometimes you may need to screen an objectionable view, and may need to

choose the window covering accordingly.

o Reduction of interior noise: window coverings can help you to reduce noises from the

interiors as well as the exterior of a house. For doing this you will need to study the

sound absorbing qualities of materials, fabric construction also impacts the degree of

sound absorption properties of window coverings.

o Need for ventilation: along with doors and ventilators, windows are the major source

of ventilation in a room. For the purpose of ventilation windows have to be operable

and operable windows determine the type of window covering used. The style of the

window can also limit the choice of window treatments.


Lesson – 20: Types of Window Treatments

Objective:

To increase awareness of window treatments and their functions

Structure:

20.1 Introduction

20.2 Draperies

20.3 Curtains

20.4 Fabric Shades

20.5 Top Treatments

20.5.1 Soft Top Treatments

20.5.2 Hard Top Treatments

20.6 Alternative Treatments

20.1 Introduction

Window treatments can broadly be classified into the following two categories.

Soft: draperies, curtains, fabric shades

Alternative: shutters, blinds, screens

20.2 Draperies

Draperies are made with pleats. They are hung with

drapery hoods onto carriers of conventional,

architectural, or decorative traverse rods or into the

rings of wood rods or cafe curtain rods; or they may

thread onto spring-system traverse rods. Generally

draperies are either hung straight to the floor or tied

back. Thus they operate, or “draw”, by opening and

closing with a cord or a wand or by hand. The

exception is tied-back draperies, which sometimes are

let down at night. However, tied-back draperies are

trained to tie back at an angle and therefore should not

be handled to any extent. Draperies draw in a pair and

meet in the centre (centre-meet) or draw one way from

left to right or from right to left. One-way draw

draperies require one-way traverse rods.


Draperies that hang at a doorway rather than at a window are

called portieres. They may be pleated in any fashion or shirred.

They may be placed on a traverse rod, but historically (and they

were used extensively in the Victorian era), they were tied-back

stationary panels made of a heavy fabric that were let down when

privacy or insulation was needed.

Draperies can be made of any fabric. The selection will depend on

the style, use, and needs. Sheer fabrics do best as diffusers of

glare and as providers of daytime privacy. Medium to heavy

weight fabrics are excellent choices for over-draperies and plain

tieback draperies. Lining fabrics are the right weight for privacy

liners or under-draperies.

Draperies are described by their pleat style or draw-type.

Pleats:

French (or pinch) pleats

Box pleats

Draw:

Two-way – separate in centre, stack to sides

One-way – stacks to one side only


20.3 Curtains

Curtains are soft window coverings that generally are shirred (gathered onto a rod) or have

headings attached to solid-wood rods, round or oval metal rods, or cafe rods rather than cord-

operated traverse rods. Curtains may be either stationary fabric panels or slid open and closed by

hand. They are flexible in that they can be short or long, layered or tiered, or used alone or in

combination with other soft, or with hard treatments. Curtain is traditionally a term for informal

treatment, such as cafe curtains. However, curtains also may be quite formal, as are shirred and

elegant tied-back fabric treatments.

Even though curtains area generally thought to be shirred treatments, other headings might be

included in this category. Indeed, there is a crossover of terminology between draperies and

curtains. Generally draperies are installed on cord-operated traverse rods, although they may be

stationary pleated panels. Curtains may be installed on traverse rods (as in a pleated cafe curtain,

for example), and headings such as the pencil pleat; drawstring pencil pleat; shirred, spaced

pencil pleat; alternate pencil pleat; ruffled shirring tape heading; and smocked heading may be

called either curtain or drapery treatment.


Curtains can be hung in various ways.


20.4 Fabric Shades

Fabric shades are panels of fabric that operate vertically. Blinds and shades are enjoying renewed

consumer interest. Manufacturers offer many new products in a wide variety of styles, colours

and innovations. For instance, look for blinds that repel dust. One model reduces static electricity

which in turn helps to keep dust from collecting on the surface. Another has an ion alignment

that repels dust particles. When shopping for blinds, especially the two-inch or larger slats, these

dust repellents could be an important factor.

Retail stores and designers show creative stylings and innovative mechanics to update traditional

products. They offer many variations of blinds and shades, including wood , vinyl and

aluminium blinds; slat widths from ½- to 2-inches or more; horizontal and vertical slats; cellular,

pleated, coach shades; and other softly-styled fabric shades. Each category has a variety of

features and qualities. Prices vary according to size, material, styling and installation.

Fabric shades include:

Balloon (or pouf)

Austrian (or shirred)

Pleated

Honeycomb

Roman


20.5 Top Treatments

Valances and cornices have played an important role in the history of window treatments, and

they are still key elements in window decor for many homes and businesses. Soft and structured

top treatments are used either by themselves or combined with draperies, curtains, blinds or

shades.

Top treatment styling varies greatly. You‟ll see pleats, points, scallops, cuffs, gathers, tabs, ties

and layers. Drapery workrooms create many unusual treatments, but no-sew and quick-sew

techniques offer lower-cost options. Experienced sewers may use structured sewing methods and

more detailed styling while new sewing aids are available for those with little time or limited

sewing skills.

Linens, towels and sheets offer quick remedies for curtains and top treatments. No-sew methods

drape, fold, knot and shape fabrics into the desired style while various tapes, pins, tacks, hook-

and-loop fasteners and holders secure the fabric in place.

Swags, cascades and jabots are classics that appear individually and in combinations. Styling

variations include formal, casual, overlapped, tied and crossed options. Swags and cascades take

on a new ambiance when slipped through sconces, draped over rods and poles or knotted in

place.

Cornices add variety and interest. Wooden cornices come in various styles with natural or

painted finishes or covered with fabric. Use them separately or combined with other fabric

treatments over blinds and shades.

Top treatments are used to:


Hide the rod or pleats

Cover area from top of window to ceiling

Give a finished look to window.

Top treatments can be soft or hard. Hard treatments are called cornices. Top treatments can be

hung on rods or attached to the wall.

20.5.1 Soft Top Treatments

Valance – a soft, horizontal treatment made entirely of fabrics mounted at the top of the

draperies.

Swags & Jabots –

Swag - fabrics festooned between two points

Jabot – fabric draped down the side of window in a folded S-shaped design generally

used with the swag.

Cascade – fabric draped like a jabot without the uniform folds.


20.5.2 Hard Top Treatments

Cornice – A firm, horizontal, boxlike structure wall-mounted at the top of draperies.

Lambrequin – A three- or four-sided cornice which completely surrounds a window

extending beyond the wall.

Cantonniere – A three-sided cornice covering the top and sides of the window fitting

flush against the wall and often extending to the floor.

All of these can be covered with fabric or made of finished wood.

20.6 Alternative Treatments

Alternative Treatments are not “soft” – do not use fabric as their primary material.

Alternative treatments include:

Metal or wood blinds (1/2” to 2 ½”)

Vertical louver blinds

Roller Shades (vinyl, vinyl-backed cloth, bamboo)

Shutters (movable louvers, Plantation shutters)

Shoji screens

Stained glass


Wooden Blinds


Lesson – 21: Window Treatment Hardware

Objective:

To examine window treatments and their characteristics

Structure:

21.1 Introduction

21.2 Tips on choosing window treatment hardware

21.1 Introduction

Someone saw a big niche in the home furnishings market about 20 years

ago. That niche was window treatment hardware.

Until then, drapery hardware consisted of unattractive white metal

traverse rods. Your only choice was how long a rod you needed. Not any

more. Drapery hardware has come out of the hardware store and into the

forefront of window covering style.

Rods and finials are offered in a huge variety of

styles including wood, metal, glass, iron, and

ceramic. The only downside is that it may take

you longer to decide on the rods than on some of

the other elements for your room!

The vast array of accessories provides one of the most dramatic changes

in window treatments. Although decorative poles have traditionally been

used, fancy finials and rings add variety and interest. Choices now

include decorative brackets, end caps, scarf holders, sconces and hold-

backs along with window art and jewellery. Use these items either alone

or in combinations.

Wood, acrylic, brass and wrought iron hardware and accessories are

available in a variety of finishes for casual or formal styles. Unfinished

wood poles can be covered with wallpaper or fabric or decorated with a

paint finish, (plain, sponging, ragging or colour washing). Pole sizes vary

in length and diameter. Finials in a design of your choice individualize

each treatment. Concealed and decorative tie-back holders and swag

holders add still more options.

Don‟t forget the more traditional sash, curtain, café, tension and traverse

rods. Some decorative traverse rods can be converted into poles. Sash and

tension rods are good choices for layered looks since they can be placed close to the glass. Use

tension rods for inside-frame installation since they won‟t damage the woodwork. They‟re also

handy for metal frame windows and for frequent movers. Magnetic brackets are also available

for metal frame window installation.


21.2 Tips on choosing window treatment hardware:

1. Decide if you want the window hardware to stand out or be "invisible". Rods and finials

might be more prominent in a formal room, for instance, while a contemporary room calls for

clean lines and an uncluttered look.

2. Consider the function of a window treatment as you choose the hardware. Draperies that

close will require easy sliding rings or a draw cord system. Stationery decorative panels can

be gathered onto a rod or hung from tab tops or ties.

3. Layer your window treatments for the most flexibility. For example,

place blinds next to the glass for privacy and light control, then add

decorative curtain panels for colour and style.

4. Use two rods or a double rod to accommodate a layer of sheers and

over drapes, or drapes and a valance.

5. Look for rods, finials, and hardware in styles and colours that will

enhance the look of your decor and the window treatments.

6. Contemporary homes will find chrome rods, glass finials, metals, iron, and cable systems to

fit in well with that look.

7. Newer cable systems are perfect for very wide windows and for contemporary rooms where

furnishings and accessories may be minimal and straight lined.

8. Match the hardware to the style of your draperies and your

room. Choose sturdy larger diameter rods for heavy draperies.

Sheer panels and lighter silks will look more appropriate on

thinner lighter rods.

9. Carved dark wood, gilt touches, and traditional shapes work

well in formal, traditional, or period rooms.

10. Scale is another important consideration. Reserve heavy

cornices and finials for larger rooms with high ceilings. Keep

the scale lighter for smaller spaces with low ceilings.

11. Iron, black wrought iron, and rustic metals might be used in

country interiors, rustic rooms, and some themed rooms in Tuscan, Spanish, and other rustic

styles.

12. Country styles can be accented with pine, iron, and simple wood rods.

13. Add height to a room by installing drapery hardware well above the window frame, or even

up along the ceiling line. The longer fabric panels will add a tall line to the rooms.


Summary:

Windows can provide ventilation, light, visual communication, and solar energy.

Functions of window treatments:

to control light

to provide ventilation

to ensure or provide privacy

to supplement energy (e.g., for heat or coolness)

to decorate a room

In above unit we have discussed different type of window treatments including different

styles, fabrics, its hardware accessories etc.

Revision points:

Functions of window treatments, to control light, to provide ventilation, to ensure or provide

privacy, to supplement energy (e.g., for heat or coolness),to decorate a room, different type of

window treatments including different styles, fabrics, its hardware accessories.

Key words:

Draperies:- Draperies are made with pleats. They are hung with drapery hoods onto carriers of

conventional, architectural, or decorative traverse rods or into the rings of wood rods or cafe

curtain rods; or they may thread onto spring-system traverse rods. Generally draperies are either

hung straight to the floor or tied back. Thus they operate, or “draw”, by opening and closing with

a cord or a wand or by hand. Draperies are described by their pleat style or draw-type

Curtains: - Curtains are soft window coverings that generally are shirred (gathered onto a rod) or

have headings attached to solid-wood rods; round or oval metal rods, or cafe rods rather than

cord-operated traverse rods. Curtains may be either stationary fabric panels or slid open and

closed by hand. Curtain is traditionally a term for informal treatment, such as cafe curtains.

However, curtains also may be quite formal, as are shirred and elegant tied-back fabric

treatments.

Soft top treatments: -Valance – a soft, horizontal treatment made entirely of fabrics mounted at

the top of the draperies, Swags & Jabots – etc

Hard top treatments: - Cornice – a firm, horizontal, boxlike structure wall-mounted at the top of

draperies.

Lambrequin – a three- or four-sided cornice which completely surrounds a window extending

beyond the wall.

Cantonniere – a three-sided cornice covering the top and sides of the window fitting flush

against the wall and often extending to the floor.

In text questions:

1. What is the importance of Window treatments in the décor of a room? Explain by giving

examples.


2. What are the different types of fabrics which can be used for covering windows? Explain in

detail any five.

3. How much thought should you give to the pattern of the fabric while selecting a window

covering material?

4. What is the need of covering windows? Explain in detail.

5. What points would you keep in mind while selecting a window treatment for a window?

6. What are draperies? Explain in detail any two types of pleats used in draperies.

7. What are curtains? Explain in detail the various methods of hanging curtains.

8. Explain in detail the different types of fabric shades used for windows.

9. What are top treatments? Explain in detail the uses and types of top treatments.

10. How do window treatment hardware help in giving a finished look to a window treatment?

Explain in detail the various types of window treatment hardware available.

11. What kind of window treatments would you recommend for the following areas. Give

reasons for your choice.

a. Office

b. Children‟s room

c. Master bedroom

d. Reception area of a hospital

e. Dining Room

Terminal exercise:

Students should do a detailed survey of the window treatment materials and hardware available

in the market today. Prepare a detailed report highlighting the cost, materials, and availability of

these products in your area. Keeping in mind different characteristics of fabric, suitable for

curtains and draperies.

Assignment / learning activities:

Students must submit a detailed report on survey of the window treatment materials and

hardware available in the market today. Prepare a detailed report highlighting the cost, materials,

and availability of these products in your area..

Supplementary material/ suggested reading:

Manufacturer‟s Details

Engineering materials (Surendra Singh)

Relevant I.S.Codes

Building Construction (Mackay, 4 Volumes)


Unit – V

Wood and Wood Products

Lesson -22: Wood and Wood Based Products

Lesson -23: Classification of Timber

Lesson -24: Seasoning Of Timber

Lesson -25: Timber Trees of India

Lesson -26: Wood Based Products

Lesson -27: Glass Terminology

Lesson -28: Glass

Lesson -29: Application of Glass in Interiors

Lesson -30: Glazing

Lesson -31: Metals

Lesson -32: Aluminium

Lesson -33: Other Metals

Lesson -34: Plastics


Lesson - 22: Wood and Wood Based Products

Objective:

To outline the functions of wood and wood based products in an interior.

Structure:

22.0 Introduction

22.1 Important technical terms

22.2 Characteristics of Good Timber

22.3 Advantages of Timber over Other Materials

22.4 Disadvantages

22.0 Introduction

The wood used for building or other engineering purposes is called timber. Timber is generally

obtained from the trunk of a tree. The timber is in the form of living tree, The freshly felled tree

and in the form of felled tree.

22.1 Important Technical Terms:

Standing timber: The timber in the form of living tree.

Green timber: The freshly felled tree which has not lost moisture.

Rough timber: The timber in the form of felled tree.

Converted timber: The timber when sawn into various market sizes such as beams, battens,

planks etc.

Dressed timber: The timber which has been sawn, placed and worked to the exact required

condition.

Structural timber: The timber used in framing and load bearing structures.

Clear Timber: Timber free from defects and stains.

22.2 Characteristics of Good Timber

Following are the characteristics of good timber:

i. It should have a uniform colour.

ii. A freshly cut surface should give a sweet smell.


iii. It should have regular annular rings.

iv. It should be sonorous when struck.

v. It should have straight and close fibres.

vi. It should be heavy in weight.

vii. It should be free from shakes, flaws, dead knots or blemishes of any kind.

viii. There should be firm adhesion of fibres and compact medullary rays.

ix. The cellular tissue of the medullary rays should be hard and compact.

x. When planed, its surface should present a firm bright appearance with a silky lustre.

xi. Its fibrous tissues should adhere firmly together and should not clog the teeth of the saw

and the freshly-cut surface should not show wooliness.

xii. A good timber should be durable. It should be capable of resisting the actions of fungi

insects, chemicals, physical agencies and mechanical agencies.

xiii. A good timber should possess the property of elasticity. The timber is elastic when it

regains its original shape and size when the load is removed. This property of timber

would be essential when it is to be used for bows, sports goods, carriage shafts etc.

xiv. It should be fire-resistant. Wood having dense texture offers great resistance to fire. It

should not contain resins and other inflammable oils which accelerate the action of fire.

xv. A good timber should be hard (i.e., it should offer resistance when it is being penetrated

by another body). The chemicals present in hard wood and density of wood impart

hardness to the timber.

xvi. A good timber should be strong for working as structural member such as joint, beam,

rafter, etc. It should be capable of taking loads slowly or suddenly.

Note: The heavier and dark coloured timber is usually strong.

22.3 Advantages of Timber over Other Materials:

i. It is stronger than other materials of construction in use.

ii. It can be easily worked to any size and shape.

iii. It can be joined to the required form easily.

iv. Structural connections can be easily made in timberwork.

v. It can be used for furniture and other decorative fittings.


vi. Timber construction is economical as the wastage is minimum.

vii. It is quite durable.

viii. Its re-sale value is good

ix. It is a non-conductor of heat and sound.

22.4 Disadvantages:

The disadvantages of timber are few, but serious. These are:

i. The greatest disadvantage is its ready combustibility, which can be diminished but not

eliminated even by expensive treatment.

ii. Frame buildings built closely together present a serious conflagration hazard.

iii. Timber is destroyed by decay induced by fungi, and by insects that feed upon the

timber under favourable conditions. Decay may, however, be prevented by the various

methods that produce an environment unfavourable for the growth of the causative

organisms.

iv. Timber swells and undergoes shrinkage with changing atmospheric humidity.


Lesson - 23: Classification of Timber

Objective:

To examine types of wood and wood products.

Structure:

23.1 Classification of trees

23.1.1 Exogenous trees

23.1.2 Endogenous trees

23.2 Comparison between Hard Wood and Soft Wood

23.3 Defects In Timbers

23.1 Classification of Trees

According to their manner of growth, the tree may be divided into two main classes:

23.1.1 Exogenous trees:

These trees grow outwards and increase in bulk by the formation of successive annular

rings on the outside under the bark.

In these trees, each annual ring represents a layer of wood, deposited every year.

The timber that is used for building and engineering purposes belongs to this variety.

Examples: Deodar, chir, sal, kail, shishum, teak, etc.

Exogenous trees may be further divided into the following two types:

Conifers trees: They remain evergreen and bear fruits in cone form with needle-pointed

leaves (and hence the name). These trees yield soft woods which are generally light

coloured, resinous, light in weight and weak. They show distinct annual rings.

Deciduous trees: They shed their leaves in autumn and put on new leaves in the spring

season. These trees yield hardwoods which are usually close-grained, strong, heavy, dark

coloured, durable and non-resinous. They do not show distinct annual rings. The timber

used for engineering purposes is mostly derived from deciduous trees.

23.1.2 Endogenous trees:

These trees grow inwards or endwards.

The stems of these trees are too flexible and thus they are not much suitable for

engineering works.

They are found generally in tropical countries and have their own limited applications for

temporary construction.


Examples: Canes, Bamboos, Palms etc.

23.2 Comparison between Hard Wood and Soft Wood

Hard Wood

A variety of exogenous trees. It is heavy in weight. The colour of hard wood is dark. It is dense,

closed grained and strong. It does not show district annual rings. Being non-resinous, it is

resistant to fire. It is relatively smooth and non-scaly.

Soft Wood

It is obtained from coniferous variety of exogenous trees. It is light in weight. The colour of soft

wood is light. It is weak and can split easily. Its annual rings are distinct. Being resinous, it can

readily catch fire. It is scaly and often gives out resinous matter.

Comparison Table of Hard and Soft Wood

S.no Aspects Soft Woods Hard Woods

1. Trees from which obtained Conifers trees Deciduous Trees

2. Annual Rings Distinct Indistinct

3. Medullary Rays Indistinct Distinct

4. Weight Light Heavy

5. Colour Light Dark

6. Structure Resinous and splits easily Non- resinous and close

grained

7. Strength Strong for direct pull and

weak for resisting thrust

or shear

Equally strong for resisting

tension, compression and

shear.

8. Fire Resistance Poor Fair

23.3 Defects in Timbers

In all kinds of timber several natural defects occur. There are caused by the nature of the soil

upon which the tree grew and also by the changes in nature to which it was subjected while

growing. As far as possible these defects should be avoided or removed during conversion for

use.

Following are the most common defects in timber:

1. Heart shakes: These are the splits or cracks widest at the centre and diminishing towards

the outside circumference. This defect usually occurs in oven natured trees and is

probably caused due to the shrinkage of the heartwood. Heartwood shake which follows a


straight course along the timber is not so serious as compared with that which follows a

twisted course.

2. Star shakes: These are radial splits or cracks widest at the circumference and get

diminishing towards the centre of the tree. Star shakes are more serious as they tend to

separate the log into a number of pieces when it is sawn. These may arise mostly from

severe frost and fierce heat of sun. They are mostly confined to sapwood.

3. Cup shakes or ring shakes: Refer Fig. 8.5. These are formed by the rupture of the tissues

in a circular direction across the cross-section of a log, usually along annular rings. When

the rupture extends only a part around, it is called a cup shake and when the whole way

round or almost so a ring shake.

4. Radial shakes: Refer Fig. 8.6. These are similar to star shakes but they are fine, irregular

and numerous. They usually occur when the tree is exposed to sun for seasoning after

being felled.

5. Rind galls: Refer figure 8.7. the rind means the bark and gall indicates abnormal growth.

Hence peculiar curved swelling formed on the body of a tree are known as rind galls.

These are generally caused by the growth of layers over the wounds left after branches

have been improperly cut off or removes.

6. Upsets or rupture: Refer Fig. 8.8. This defect is due to crushing of fibres which are

deformed as a result of the injury thus caused. These are due to unskilful felling and also

the result of violent wind.

7. Twisted fibres or wandering hearts: Refer Fig. 8.9. This defect is developed in a tree

owing to its peculiar position where the prevailing winds turn the tree constantly in one

direction. The fibres of such a tree are twisted longitudinally and if planks or any sections

are cut from it, many of the fibres would be cut through and the strength of the pieces is


reduced. The timber with twisted fibres is unsuitable for sawing. It can however be used

for posts and poles in an unsawn condition.

8. Burrs or excrescence: These are either due to unsuccessful attempts at the formation of

branches or due to injuries inflicted when the tree was young, so that undeveloped,

dormant buds grew and produced masse of contorted tissue. Technically, they are defects

but, in practice, they produce valuable figure-wood for veneers.

9. Wind cracks: when wood is exposed to atmospheric agencies, its exterior surface shrinks.

Such a shrinkage results in cracks.

10. Knots: Refer Fig. 8.11.

Knots are the roots of small branches of the tree. Knots disturb the homogeneity of

wood texture. The fibres of wood get twisted or curled in the vicinity of knots and

this affects the strength of the wood. The position, size of the knot, and the degree of

grain distortion around it, determine the magnitude of the reduction in strength that

the knot can cause.

When the formation of knot is free from decay and other defects and is firmly intact

with the surrounding wood, it is called a live knot or sound knot. A knot which is not

held firmly in place it called a dead knot or loose knot.

There are various types of knots, most common being:

Round knot, oval knot, spike knot, grouped knot and pencil knot.

Timber containing large dead (loose) knots or many smaller ones should be rejected,

as they are poorer in appearance and strength.


Lesson - 24: Seasoning of Timber

Objectives: To study about the seasoning of timber.

Structure:

24.0 Introduction

24.1 Objectives of Seasoning

24.2 Advantages of Seasoning

24.3 Methods of Seasoning of Timber

24.3.1 Natural seasoning

24.3.2 Water Seasoning

24.3.3 Artificial Seasoning

24.4 Conversion of Timber

24.0 Introduction

Seasoning of timber is the process of drying timber or removing moisture or sap, present in a

freshly felled timber, under more or less controlled conditions.

Freshly felled timber contains a large quantity of moisture roughly from 100 to 200%, based on

dry weight of wood. A well-seasoned piece of wood may contain about 10 to 12% moisture and

will be in equilibrium with the atmospheric humidity of a particular place.

If the timber is used without seasoning, it is liable to shrink, warp and crack, and may even rot

and decay. Thus all timber should be properly seasoned. Seasoning should be the first step for

efficient usage of timber.

24.1 Objectives of Seasoning

The following are the main objectives of seasoning of timber:

1. To check/minimise the tendency of timber to shrink, warp and split.

2. To increase strength, durability and electrical resisting power of the timber.

3. To maintain the shape and size of the components of the timber articles which are

expected to remain unchanged in form.

4. To make timber safe from attack of fungi and insects.

5. To reduce the weight for transport purposes, handling, and thereby reduction in cost.

6. To make timber fit for receiving treatment of paints, preservatives and varnishes.

7. To make timber easily workable and to facilitate operations during conversions.

8. To make timber suitable for gluing (i.e. effectively joining two members of timber with

the aid of glue).


24.2 Advantages of Seasoning

Following are the advantages of seasoning timber:

1. Seasoning makes the timber less liable to attack by insects and fungus.

2. It decreases the weight of timber and makes it lighter.

3. It enables timber to be easily painted, polished and preserved.

4. It avoids defects appearing in timber during its use.

5. It improves the strength properties of the timber and makes it more stable.

6. It improves working qualities of timber.

7. It provides dimensional stability and retention of shape to the timber used in carpentry or

joinery.

8. Seasoning increases the power in timber to held metal fasteners.

24.3 Methods of Seasoning of Timber

Seasoning of timber may be carried out in two ways:

24.3.1 Natural seasoning Air Drying/Seasoning:

In this method of seasoning the sawn

timber is stacked in a dry place about 30

cm above floor level with longitudinal

and cross pieces arranged one upon the

another, leaving a space of a few cms in

between, for free circulation of air. To

keep wood clear of the ground, a

suitable foundation is provided. To

protect the stacks of wood from direct

sunlight either a pitched roof is used or

stacks are kept in shade.

Wood seasoned by this method is

generally fit for carpenter‟s work after

two years and for pointer‟s work after

nearly four years.

Advantages:

1. Natural or air seasoning does not necessitate much attention.

2. It is a simple and cheap method.

3. There are comparatively less chances of damage to the timber.

Disadvantages:

1. The process is very slow and extends over years.

2. For large stacks considerable space is required.


3. It blocks the capital for a very long time.

4. Even under favourable conditions, it is difficult to reduce the moisture content to suit the

requirements of certain jobs.

5. Timber may get damaged by insects and fungi during the seasoning period.

24.3.2 Water Seasoning:

In this method of seasoning timber consists of keeping logs of wood completely immersed on a

running stream of water; the longer ends of the logs being kept pointing up-stream. By this

process, the sap, sugar and gum etc., are leached out of the wood and replaced by water. The logs

are then taken out and left to dry in an open place.

Advantages:

Water seasoning is associated with the following advantages:

i. It is a quick process.

ii. As immersion in water causes more rapid and regular drying, the tendency of wood

shrink or warp is reduced.

iii. As all organic food materials present in the sap wood are washed away, the wood is

rendered less liable to be eaten away by worms or to decay to dry rot.

Disadvantages:

i. The process reduces the elasticity and durability of the timber

ii. The timber is rendered brittle.

24.3.3 Artificial Seasoning

The artificial methods of seasoning are quick

and the moisture content can be kept under

control, which may vary from 4-12%

depending upon the tropical conditions of

the region where the product is to be used.

For dry regions the water content may be 4-

6% whereas in humid areas it may be around

10%. The most common method of artificial

seasoning if kiln seasoning.

Kiln Seasoning: In this system the timber is

seasoned under controlled temperature and

humidity conditions with proper air

circulation and ventilation system. The rise

in temperature should be such that the timber

retains the original strength and elasticity.

The required humidity level is maintained to

avoid warping and cracking.


The timber, inside the hot chamber, on the trolley is kept under controlled conditions for about a

fortnight or so depending upon the initial water contents and the required moisture level. The

quality of wood obtained by this method is inferior as compared to the one seasoned by natural

methods.

Advantages

Following are the advantages of kiln seasoning:

i. The moisture content can be reduced as per requirement.

ii. The timber can be seasoned thoroughly well and in short span of time under controlled

conditions.

iii. The timber seasoned by the method is less liable to shrinkage.

iv. The wood can be used immediately as and when required.

v. The drying is controlled and there are practically no chances for the attack of fungi and

insects.

vi. The drying of different surfaces is even and uniform.

Disadvantages

Kiln seasoning entails the following disadvantages:

i. This method is costly (though the space required is less).

ii. It requires skilled labour.

iii. Due to the process of drying being a quick, a continuous attention needs to be given to

check seasoning defects such as warping, internal cracks, surface cracks and end-splits.

24.4 Conversion of Timber

After felling a tree, it is generally cut into standard sections to minimise wastage of wood. The

process by which the timber is cut and sawn into suitable sections is known as the conversion of

timber.

The following points regarding conversion of timber are worth noting:

a) The conversion of timber should be done in such a way that wastage of useful timber is

minimum.

b) An allowance of 3 mm to 6 mm should be made for squaring. planning and shrinkage.

c) The saw cuts should be made tangential to the annual rings and practically parallel to the

direction of medullary rays. By doing so. strong timber pieces are obtained.

d) The wooden beams should be sawn in such a fashion that they do not contain pith in their

cross-section; this is achieved by sawing the timber first through pith into two halves.


Lesson - 25: Timber Trees of India

Objective:

In this lesson we will discuss different timber tree in India like kail, babul, shisham, mango,

teak etc and some market forms and sizes of timer like log, baulk, bole, plank, billet etc.

Structure:

25.1 Common Market Forms and Sizes of Timber

25.2 Timber Trees of India

25.2.1 Deodar

25.2.2 Babul

25.2.3 Teak

25.2.4 Shisham

25.2.5 Mango

25.2.6 Mahogany

25.2.7 Walnut

25.2.8 Mulberry

25.2.9 Sal

25.2.10 Chir

25.2.11 Kail

25.2.12 Bamboo

Introduction

Some of the important timber trees in India are: - Deodar, babul, teak, shisham, mango,

mahogany etc,

25.1 Common Market Forms and Sizes of Timber

Log: The stem or trunk of tree which is felled with branches cut off.

Baulk: A piece of sawn timber, the cross-sectional dimensions of which exceed 5 cm in

one direction and 20 cm in other direction.

Battles: A piece of sawn timber, the dimensions do not exceeding 5 cm either in breadth

or in thickness.

Bole: The main stem of a tree.

Bolt: A short log 1.25 m or less in length.

Billet: A short length of a thin stem or branch.

Plank: A piece of sawn timber with thickness not exceeding 5 cm and the width

exceeding 5 cm.

Board: A thin blank generally under 5 cm thick and 10 cm.


Cant: A thick piece of timber with or without squared edges, sawn from a log and

intended for further conversion into smaller sizes.

Deal: a swan piece of wood which is 5 cm to 10 cm thick and 20 cm to 25 cm wide.

Deal wood: The light timber used for packing cases.

Hewn timber: The timber converted to size by an axe.

Pole: A long, solid, straight trunk of a tree 10 to 30 cm in diameter at breast height and

tapering gradually to the top.

Post: A timber member used in an upright position in building.

Scantling: A piece of timber, the cross-sectional dimension of which exceed 5 cm in both

the directions but do not exceed 20 cm.

Slat: In pencil manufacture. A sawn piece of wood about 185 mm x 65 mm x 6 mm in

size.

Sleeper: A piece of timber used as transverse support under rails in railway lines

Strip: A piece of timber under 5 cm thick and less than 10 cm wide.

25.2 Timber Trees of India

Description of some important timber trees in India is given below:

25.2.1 Deodar:

It is a tall tree with long pointed leaves and is generally found in

hills. It is the most important timber tree providing soft wood.

Characteristics

i. It yields soft wood having well defined grains.

ii. It is highly durable.

iii. It is light coloured wood and has distinct annual rings.

iv. Its average weight is 5450 N/m3 (at 12 per cent moisture

content).

v. It is strongly scented, oily and polishes well.

vi. It is moderately strong

vii. It can be easily worked.

Uses: It is used for making cheap and rough furniture, railway carriages, railway sleeper, packing

boxes, structural work etc.

25.2.2 Babul:

This tree grows all over India and is available in abundance. It seldom attains a height greater

than 15 m.


Characteristics:

i. Its colour is whitish red.

ii. It takes up good polish.

iii. Its average weight is 7000 N/m3.

iv. It is not very durable.

Uses:

i. It is employed for constructional purposes, agricultural implements and tool handles.

ii. It is also used in low cost house construction and bullock carts.

25.2.3 Teak:

Teak wood is one of the best available hard woods. Its durability

is due to the presence of aromatic oil which largely preserves it

from the attack of white ants. It grows in Malabar (South India)

and Central India.

Characteristics:

i. It is strong and durable.

ii. Its colour is deep yellow to dark brown.

iii. Its average weight is 6400 N/m3.

iv. It is not difficult to work and can be finished and polished to obtain an excellent surface.

v. It can be easily recognised by virtue of its distinct smell.

vi. It is resistant to moisture and certain chemicals.

vii. It does not corrode iron fastenings.

viii. It shrinks little.

ix. It can be easily seasoned.

x. It is fire-resistant.

xi. It is not attacked by white ants and dry rot.

xii. It is moderately hard.

Uses:

i. It is used for heavy construction of permanent character like shipbuilding, piling, railway

sleepers etc.

ii. It is also employed for high-class joinery and furniture.

iii. Its use is limited to superior work only as it is comparatively very costly.


25.2.4 Shisham (Tali):

It grows widely in Punjab, Uttar Pradesh and Madhya Pradesh.

Characteristics:

i. It is a broad leaved tree.

ii. It is moderately durable.

iii. Its average weight is 7000 N/m3

iv. The wood is dark brown in colour.

v. It is coarse grained.

Uses: It is used for constructional purposes, furniture and cabinet making, agricultural

implements and bridge-piles etc.

25.2.5 Mango:

This tree is very famous for its fruit and is found all over India.

Characteristics:

i. Its wood is of inferior quality.

ii. It is coarse and open-grained.

iii. It has deep grey colour.

iv. The wood is readily attacked by white-ants and decays on exposure to wet atmosphere.

v. Its average weight is 6900 N/m3.

vi. Easy to work but keeps its shape well.

Uses:

It is used for packing cases of all sorts, cheap furniture, tonga bodies, pattern making and

ornamental cabinet work.

25.2.6 Mahogany:

It is a native tree of Cuba in West Indies and Central America. It is now becoming popular in

India also.

Characteristics:

i. It has fine wavy grains.

ii. Reddish brown colour.

iii. Durable in water.

iv. Hard but easy to work.

v. Average weight 6700 N/m3.

vi. Takes high polish.

Uses: It is used for high-class furniture, pattern making and ornamental cabinetwork.


25.2.7 Walnut:

It is available mostly in hilly areas.

Characteristics:

i. Light brownish colour.

ii. Broad leaved tree.

iii. Average weight 5750 N/m3

iv. Less durable.

v. Resists the attack of white ants.

vi. Easy to work.

vii. Tough and flexible.

Uses:

It is employed for furniture, decorative work and cabinetwork.

25.2.8 Mulberry:

This tree yields strong, tough and elastic wood.

Characteristics:

i. Wood can be easily turned, carved and finished to a smooth surface.

ii. Wood is of brownish colour.

iii. Broad-leaved tree.

iv. Average weight is 6750 N/m3.

v. Seasons well.

Uses:

It is used for making sports goods like hockey sticks, tennis and badminton racket

25.2.9 Sal:

It is available mostly in hilly areas of U.P., Bihar, Assam and Visakhapatnam.

Characteristics:

i. Wood is hard, close-grained, heavy and durable.

ii. Not easily attacked by white ants.

iii. Average weight is 8600 Nlm3.

iv. Easily worked but does not take good polish.

v. Seasons slowly.


Uses:

It is used in bridge construction, ship building, piling etc. It is however, not used for ornamental

work.

25.2.10 Chir:

It is available in Himalayan region.

Characteristics:

i. Reddish brown in colour.

ii. Average weight is 5700 Nlm3.

iii. Less durable.

iv. Easily worked but cracks.

v. Seasons well.

Uses:

It is employed for inferior woodwork in low cost house building.

25.2.11 Kail:

It is mostly grown in Himalayan region.

Characteristics:

i. Wood is close grained, heavy, moderately hard and durable.

ii. Brown in colour.

iii. Average weight is 5000 Nlm3.

iv. Seasons well.

Uses:

i. It is used for door and window frames and panels, furniture making, beams, posts etc.

ii. It is also used in heavy engineering works such as bridge construction, ship building,

piling etc.

25.2.12 Bamboo:

It grows in large varieties in Bengal, Assam and South India. Small

varieties are found in low hills also.

Characteristics:

Strong and durable.

Uses:

i. It is used in scaffolding, lanterns and bridge building.

ii. It is also employed for partitions, flooring, ceiling, roofing and almost all parts of house

construction except for the fireplace.


Lesson - 26: Wood Based Products

Objective:

The products manufactured from different types of wood are called wood based products like:

-veneer, plywood, boards like lamin board, block board, batten board etc.

Structure:

26.0 Introduction

26.1 Forms of Wood Based Products

26.1.1 Veneers

26.1.2 Plywood

26.1.3 Batten Boards and Block Boards

26.1.4 Lamin Boards

26.1.5 Fibre Boards

26.0 Introduction

The product manufactured from different types of wood are called wood based products. Some

important technical terms used in the manufacture of wood based products.

Bond: An adhesive used on the wood at the time of application is called bond.

Bonding: The process of uniting two or more pieces of wood by means of an adhesive.

Core: The inner layer or layers of plywood.

Glue Line: The resultant layer of adhesive affecting union between any two adjacent

pieces in an assembly.

Ply: Individual layers of veneer. :

Three Ply: Plywood board made from three layers of veneers having thickness from 3

mm to 50 mm.

Multi-Ply: Plywood board made of more than three layers of veneers.

Open Defect: A defect in the plywood.

Pleat: A defect in the plywood due to a veneer being folded parallel to the grain.

26.1 Forms of Wood Based Products

26.1.1 Veneers

The layers or sheets of varying thickness from 1 to 6 mm are called veneers. These are obtained

with a rotary peeling machine. They are peeled off the log by a sharp knife in a long continuous

sheet by rotating the log on its longitudinal axis. They are slued from logs of timber having

extremely attractive and curly figures such as teak, sisoo, toon, mahogany, Walnut, Oak etc.

They are used in construction where light, strength, non-shrinking and non-splitting properties

are expected of timber.


26.1.2 Plywood

A board formed by gluing together three or more layers of veneers or plies is known as plywood.

The veneers are glued together usually with the grains of adjacent veneers running at right angles

to each other. This cross binding of odd numbers of plies makes the plywood less prone to

shrinkage. The outer ones are termed as face plies and the inner one as the core or cross band.

Advantages of Plywood:

i. It gives better appearances as it can be formed in decorative designs and patterns by

selecting figured veneers.

ii. It is light in weight and has greater strength.

iii. It gives uniform tensile strength in all directions.

iv. It is obtainable in required size. It is very easy to work.

v. It is highly resistant to cracking, splitting and wrapping etc.

Uses

It is used commonly now days to save the increased cost of hard wood planks. It is mainly used

for the construction of furniture, partition, ceiling, doors, and windows and for decorative

purposes inside and outside the buildings.

26.1.3 Batten Boards and Block Boards

The boards having a core slab consisting of strips which are glued together between two veneers,

one or either side, are known as batten boards or block boards. The direction of the grains of core

battens is kept at right angles. They are manufactured or made on similar lines as plywood. They

are not light but are comparatively strong. They do not split or crack easily.


Uses

Batten boards are used for making partitions, packing, cases, floors, furniture panelling, bus

bodies, railway coaches or table tops etc.

26.1.4 Lamin Boards

The boards having core of strips not exceeding 7 mm in thickness glued together between two or

more veneers are known as lamin boards. They are also made on similar lines as plywood. lamin

boards are stronger and durable. Lamin boards are used for making partitions, packing cases and

for floors etc.

26.1.5 Fibre Boards

The boards which are made by pressing the mixture of saw dust, fibres of wood and glue are

known as fibre boards.

Manufacture of Fibre Boards

To manufacture fibre boards, the

selected wood is converted into chips

about 2 cm long. These chips are put

into an air tight steel vessel, called the

gun and subjected to steam pressure of

30 to 60 kg/cm2. This process softens

the wood gum which keeps the wood

fibres in contact. They are than

discharged by opening a value at the

bottom. The wood fibres will come out

from the cylinder with a great force. These fibres are refined, spread out on screens in the form

of mats of required thickness and subjected to heat and great pressure in hydraulic presses to

form solid dry sheets, known as fibreboards. These boards are generally from 3 to 12 mm in

thickness, 1.2 to 5.5 in length and 1.2 m in width.


Fibre Boards are classified as under

i. Insulating Boards

ii. Light and hard Boards

iii. Laminated fibre building boards.

Uses

i. They are used for internal finish as well as panelling, suspended ceilings and for floors.

ii. They are used for insulation against heat and sound.

iii. They are used in making partitions.

iv. They are used in making flush doors, tabletops, for bus bodies, railway coaches etc.


Summary:

The unit discussed above include the uses of wood and wood products in an interior such as: for

structural purposes: Doors and windows, Floors, Ceilings, Furniture items, for decorative

purposes like: Trims and beadings and Panelling etc

Detailed studies of the types of wood and their characteristics and Main woods of India like

Teak, deodar, shisham, mahogany, walnut, sal etc. Characteristics of good timber, defects in

timber, seasoning of timber etc.

Revision points:

Detailed studies of the types of wood and their characteristics and Main woods of India like

Teak, deodar, shisham, mahogany, walnut, sal etc. Characteristics of good timber, defects in

timber, seasoning of timber etc.

Key words:

Timber: - is the wood suitable for building or engineering purposes and it is supplied to trees

measuring not less than 0.5 m in girth.

The most common defects are:-

Heart shake, star shake, cuoshake, radial shake, rind galls, upset, twisted fibres, burns, wind

cracks, knots, honeycombing etc.

Veneers:- are thin sheets or slices of wood of superior quality, having thickness varying from

0.4mm to 6 mm or more.

Plywood: - is made by cementing together several layers of wood which may be thin veneers or

thicker boards.

Intext questions:

i. What is timber? Discuss in detail the characteristics of a good timber.

ii. What are the advantages and disadvantages of using timber as compared to other

materials?

iii. Into how many classes can trees be divided based upon their manner of growth? Discuss

in detail.

iv. Discuss in detail the most common defects found in timber.

v. What is the purpose of seasoning timber? Discuss in detail the various methods of

seasoning timber.

vi. Write down the various market forms and sizes of timber.

vii. Give the characteristics and uses of the following timber trees:

a) Deodar

b) Teak

c) Mango

d) Shisham


e) Chir

i. What are wood based products? Discuss in detail the advantages of using these products

as compared to using wood.

ii. write short notes on the following:

a) Veneers

b) Plywood

c) Blockboard

d) Prelaminated board

iii. Do a detailed market survey of the wood and wood products available in your area and

prepare a project report.

Terminal exercise

A detail market survey to be done by the students wherein they will study all the aspects of

timber and will also prepare a comparative chart of the characteristics and cost of the various

wood and wood products available in the market.

Assignment/ learning activities

Students have to prepare a comparative chart of the characteristics and cost of the various wood

and wood products available in the market.

Supplementary materials/ suggested reading

i. Engineering materials by Surendra Singh

ii. Engineering Materials by Rajput

iii. Time Savers Standards for Interior Design and Space Planning

iv. Trade magazines


Lesson - 27: Glass Terminology

Objective:

To study about types of glass

Structure:

This chapter include all basic terminology of glass.

Introduction

The various types of glass available in the market and its basic

terminology like Annealing, annealed glass, bevelling etc

Annealed Glass: Standard float glass.

Annealing: In the manufacturing of float glass, it is the process of

controlled cooling done in a lehr to prevent residual stresses in the glass.

Re-annealing is the process of removing objectionable stresses in glass

by re-heating to a suitable temperature followed by a controlled cooling.

Annealing Lehr: An on-line, controlled heating/cooling apparatus

located after the tin bath & before the cooling conveyor of a float glass

production line. It's purpose is to relieve induced stress from the flat

glass product to allow normal cold end processing.

Beveling: The process of edge finishing flat glass to a bevel angle.

Bow (& Warp): A curve, bend or other deviation from flatness in glass.

Bubbles: In laminated glass, a gas pocket in the interlayer material or

between the glass & the interlayer. In float glass, a gaseous inclusion

greater than 1/32" in diameter.

Bullet Resistant: A multiple lamination of glass or glass and plastic

designed to resist penetration from medium-to-super-power small arms

and high-power rifles.

Caulk: The application of a sealant to a joint, crack or crevice. A

compound used for sealing that has minimum joint movement

capability; sometimes called low performance sealant.

Caulking: The blocking of exterior air or moisture leaks by filling

cracks around doors, windows, or anywhere else where two surfaces meet and have minimum

movement with a "putty" compound. Large cracks can be stuffed with mineral wood and weather

sealed with caulking

Curtain wall: An exterior building wall which carries no roof or floor loads and consists entirely

or principally of metal or a combination of metal, glass, and other surfacing materials supported

by a metal frame. There are two basic types:


Custom - Walls designed specifically for one project, and using parts and details

specially made for this purpose;

Standard - Walls made up principally of parts and details standardized by their

manufacturer and assembled in accord with either the architect's design or the

manufacturer's stock patterns.

Cutting: Scoring glass with a diamond, steel wheel, or other hard alloy wheel & breaking it

along the score. Other methods of cutting glass include water

jet & laser.

Distortion: Alteration of viewed images caused by variations

in glass flatness or inhomogeneous portions within the glass.

An inherent characteristic of heat-treated glass.

Double Glazing: In general, any use of two thicknesses of

glass, separated by an air space, within an opening, to improve

insulation against heat transfer and/or sound transmission. In

factory-made double glazing units the air between the glass

sheets is thoroughly dried and the space is sealed airtight,

eliminating possible condensation and providing superior

insulating properties.

Fenestration: Any glass panel, window, door, curtain wall, or

skylight unit on the exterior of a building.

Flat glass: A general term that describes float glass, sheet glass,

plate glass and rolled glass.

Float glass: Glass formed on a

bath of molten tin. The surface

in contact with the tin is known

as the tin surface or tin side. The top surface is known as the

atmosphere surface or airside. Glass which has its bottom

surfaces formed by floating on molten metal, the top surface

being gravity formed, producing a high optical quality of glass

with parallel surfaces and, without polishing and grinding, the

fire-finished brilliance of the finest sheet glass.

Fully Tempered Glass: Fully tempered glass if broken will

fracture into many small pieces (dice) which are more or less

cubical. Fully tempered glass is approximately four times

stronger than annealed glass of the same thickness when

exposed to uniform static pressure

loads. Outside of North America is

sometimes called "toughened glass".

Glass: A hard brittle substance, usually transparent, made by fusing

silicates, under high temperatures, with soda, lime, etc.


Heat Absorbing Glass: Glass that absorbs an appreciable amount if

solar energy.

Heat-resistant glass: Glass able to withstand high thermal shock,

generally because of a low coefficient of expansion.

Heat-Strengthened Glass: Twice as strong as annealed glass;

therefore, it is able to resist slightly stronger impacts. Produced in a

similar manner to tempered glass (slower cooling than tempered).

Heat strengthened glass is not considered safety glass & will not

completely dice as will fully tempered glass.

Heat Treated: Term used for both fully tempered glass & heat-

strengthened glass.

Insulating Glass: Insulating glass refers to two pieces of glass spaced

apart and hermetically sealed to form a single-glazed unit with an air space between. Heat

transmission through this type of glass may be as low as half that without such an air space. It is

also called Double Glazing.

Lite: Another term for a pane of glass used in a

window. Frequently spelled "light" in the industry,

but often spelled "lite" in text to avoid confusion

with light as in "visible light".

Patterned glass: One type of rolled glass having a

pattern impressed on one or both sides. Used

extensively for light control, bath enclosures and

decorative glazing. Sometimes called "rolled",

"figured" or "obscure" glass.

Plate Glass: Polished plate glass is a rolled, ground

and polished product with true flat parallel plane

surfaces affording excellent vision. It has less surface polish than sheet glass and is available in

thickness varying from 1/4" to 1-1/4". Now replaced by float glass.

Polished Wire Glass: Wired glass that has been ground & polished on both surfaces.

Reflective Glass: Glass with a metallic coating to reduce solar heat gain.

Rolled glass: Glass formed by rolling, including patterned and wired glass.

Sandblasted Finish: A surface treatment for flat glass obtained by spraying the glass with hard

particles to roughen one or both surfaces of the glass.

Glazing: (n) A generic term used to describe an infill material such as glass, panels, etc. (v) The

process of installing an infill material into a prepared opening in windows, door panels,

partitions, etc.

Sheet Glass: A transparent, flat glass whose surface has a characteristic waviness replaced by

float glass. There were three basic classifications of sheet glass: 1) single strength 3/32" thick; 2)

double strength: 1/8" thick; 3) heavy sheet which has 3 thicknesses: 3/16", 7/32" and 1/4


Solar Control Glass: Tinted and/or coated glass that reduces the amount of solar heat gain

transmitted through a glazed product.

Tempered Glass: As with heat-strengthened glass, it is re-heated

to just below the melting point, but suddenly cooled. When

shattered it breaks into small pieces. It is approximately five

times stronger than standard annealed glass. It must be used as

safety glazing in patio doors, entrance doors, side lites, and other

hazardous locations. It can't be re-cut after tempering. Fully

tempered glass is approximately four times stronger than

annealed glass of the same thickness when exposed to uniform

static pressure loads.

Tinted glass: Glass with colorants added to the basic glass batch

that gives the glass colour, as well as, light and heat-reducing capabilities. A mineral admixture

is incorporated in the glass, resulting an a degree of tinting. Any tinting reduces both visual and

radiant transmittance

Transmittance: The ability of the glass to pass light and/or heat, usually expressed in

percentages (visible transmittance, thermal transmittance, etc.)

Double strength: In float glass, approximately 1/8" (3 mm) thick

Edgework: Grinding the edge of flat glass to a desired shape or finish.

Etch: To alter the surface of glass with hydrofluoric acid or other caustic agents. Unintentional

permanent etching of glass may occur from alkali and other runoff from surrounding building

materials.

Wire glass: Rolled glass with a layer of meshed or stranded wire completely imbedded.

Available as polished glass and patterned glass. Approved polished wired glass is used as

transparent or translucent fire protection rated glazing. The wire restrains the fragments from

falling out of the frame when broken. Polished or clear glass 1/4" thick. Wire mesh is embedded

within the glass such that the glass will not shatter when broken. The wire pattern is available in

many types. It is frequently used in skylights, overhead glazing, and locations where a fire-

retardant glass is required.

Laminated Glass: Two or more sheets with an inner layer of transparent plastic to which the

glass adheres if broken. Used for overhead, safety glazing, and sound reduction. Can be made of

any kind of glass, but is most typically made of annealed, heat-strengthened, or tempered glass.


Lesson - 28: Glass

Objective:

To study the properties of glass and find out about the various types of glass used in

interiors

Structure:

28.1 Introduction

28.2 Structure of glass

28.3 Constituents of Glass and Their Functions

28.4 Properties of Glass

28.5 Requirements of Commercial Glass

28.6 Classification of Glass

28.6.1 Soda lime or crown glass

28.6.2 Flint glass

28.6.3 Pyrex or heat resistant glass

28.7 Special types of glasses

28.7.1 Float glass

28.7.2 Glazing

28.7.3 Laminated glass

28.7.4 Tempered glass

28.7.5 Wired glass

28.7.6 Glass block

28.7.7 Insulated glass

28.7.8 Curtain walls

28.1 Introduction

Glass is any substance or mixture of substances that has solidified from the liquid state without

crystallization. Elements, compounds and mixture of varying composition can exist in the glass

state, but the term “glass” as ordinarily used refers to material which is made by the fusion of

mixture of silica, basic oxides and a few other compounds that react either with silica or with the

basic oxides. No definite chemical compound can be identified in glass. Many of its properties

correspond to those of a super cooled liquid whose ingredients can not be identified because they

have not separated from the solution in crystalline form.

Glass may also be defined as a hard, brittle, transparent or translucent material chiefly a

compound of silica, combined with varying proportions of oxides of sodium, potassium calcium,

magnesia, iron and other minerals.

Glass is an amorphous substance having a homogeneous texture.


28.2 Structure of glass:

The glass is a random arrangement of molecules, the great majority of which are oxygen ions

bounded together with the network forming ions of silicon, boron or phosphorous. A glass made

of silica alone has many desirable characteristics but unfortunately the high temperatures

involved make it expensive, and difficult to prepare. In order to reduce the temperature, required

network-modifying ions are added. Sodium, potassium and calcium are the most common.

28.3 Constituents of Glass and Their Functions

The various constituents of glass and their functions are described below:

1. Silica:

It is the principal constituent of glass.

If silica alone is used in the manufacture of glass, it could be fused only at a very high

temperature but it would give a good glass on cooling. However, it is imperative to add

some alkaline materials (sodium or potassium carbonate) and lime in suitable proportion

to make this glass workable and resistant to weathering agents.

2. Sodium or potassium carbonate:

It is an alkaline material and forms an essential component of glass.

It is added in suitable proportion to reduce the melting point of silica and to impart

viscosity to the molten glass.

3. Lime:

It is added in the form of chalk.

It is imparts durability, to the glass.

In place of lime, sometimes, lead oxide is also added; it makes the glass bright and

shining.

4. Manganese dioxide;

It is added in suitable proportion to correct the colour of glass due to the presence of iron

in raw materials of glass.

It is also called 'Glass maker' soap.

5. Cullet

It is the old broken glass of the same type as that which is intended to be prepared.

It is added in small quantity to provide body to the glass.

6. Colouring substance:

While manufacturing a coloured glass, a suitable colouring substance is added at fusion stage to

provide the desired colour to the glass.


The various colouring substances for manufacturing glass of different colours are given below;

Colour Colouring substance Colour Colouring substance

Black Cobalt, nickel and

manganese oxide

Violet Manganese dioxide

Green Chromic oxide White Cryolite, tin oxide

Red Cuprous oxide, selemium Yellow Cadmium sulphate

28.4 Properties of Glass

Following are the properties of glass:

1. No definite crystalline structure.

2. No sharp melting point.

3. Absorbs, refracts or transmits light.

4. Affected by alkalies.

5. An excellent electrical insulator at elevated temperatures.

6. Extremely brittle.

7. Available in beautiful colours.

8. Not affected by air or water.

9. Not easily attacked by ordinary chemical reagents.

10. Capable of being worked in several ways.

11. Can take up a high polish (and may be used as substitute for very costly gems).

12. Possible to weld pieces of glass by fusion.

13. As a result of advancement made in the science of glass production, it is possible to make

glass lighter than cork or softer than cotton or stronger than steel.

14. Glass can be cleaned easily by any of the following methods:

Applying methylated spirit.

Rubbing finely powdered chalk.

Rubbing damp salt for

Painting the glass panes with lime-wash cleaning paint spots, and leaving it to dry and

then washing with clean water.

28.5 Requirements of Commercial Glass

i. The material must melt at commercially obtainable temperature. Fused silica cools to a

glass that is superior to ordinary glass, but the temperature required to melt it is so high

that its production is expensive and its use restricted.


ii. The molten mixture must remain in the amorphous or non-crystalline condition after

cooling.

iii. The fluidity of molten glass must persist to a sufficient extent to permit the formation of

desired shaped while the glass is cooling.

iv. The glass must be reasonably permanent in the use for which it is intended. Water and

acids more readily attack glass with a high proportion of sodium oxide than glass that

contains less sodium oxide and more lime and magnesia. Glasses low in basic oxides are

less readily attacked.

28.6 Classification of Glass

Glass may be classified in the following categories based upon its composition and properties:

28.6.1 Soda lime or crown glass:

It is the cheapest quality of glass.

Its composition is not rigidly fixed, but can be varied both as to the amount of ingredients

and the chemical compound used.

It is easily fusible at low temperatures.

It has a clean a clear state.

It is possible to blow or to melt articles made of this glass with the help of simple sources

of heat.

Uses: it is typically used for window glazing, plate glass and container bottles.

28.6.2 Flint glass:

It contains varying proportions of lead oxide to make it suitable for various purposes.

Leads provides brilliance and high polish to the glass making it suitable for special

purposes.

It liquefies at a lower temperature than soda-lime glass and has a better lustre.

28.6.3 Pyrex or heat resistant glass:

Both soda-lime and flint glass are unable to withstand sudden temperature changes due to their

large co-efficient of thermal expansion. Elimination of the basic oxides and inclusion of boron

oxide produce a glass that is very resistant to thermal shock and to attack by water and acids. The

temperature required to melt and fine such a glass is so high that it has to be heated in the electric

arc The familiar Pyrex glasses, which are used extensively for cooking utensils and laboratory

wares, are borosilicate glasses.

28.7 Special types of glasses:

There are several types of glass, as a designer, you need to understand the differences and

appropriate uses of each.


28.7.1 Float glass

Float glass is the most common type of glazing in use today. It succeeds plate glass, and has

very similar qualities to plate glass (although float glass is less expensive), except the

manufacturing process is different. There is no need to polish or grind float glass (plate glass is

polished for an exceptionally clear quality). Float and plate glass can be treated in various ways

during the manufacturing process to reduce heat

transfer (such as with low-E glass), alter

visibility (mirrored coatings), and to tint the

glass with a colour.

28.7.2 Glazing

Glazing refers to the panes or sheets of glass

that are set into a frame or frameless condition.

28.7.3 Laminated glass

Laminated glass refers to two or more layers of

glass that have been laminated together, most

often the bonding occurs with polyvinylbutryal.

The glass being laminated together can be float, tempered, or heat-strengthened glass. Laminated

glass has higher impact strength than other types of glazing working alone. When laminated

glass is broken, the inner layer of laminating material holds the glass pieces together. Unless the

glass laminated together is tempered glass, the lamination process does nothing to affect the

shards of glass present, it merely holds them together. Several characteristics of glazing can be

enhanced or introduced with the use of laminated glass. The glass may be designed for security

purposes (bullet-resistant glass is a laminated product), for acoustical performance (laminated

glass has much better sound resistance than float or tempered glass), for privacy purposes (a

chemical can be introduced to the lamination that, when activated, causes the glass to appear

opaque). In addition, patterns and graphics may be laminated within the glass. Laminated glass is

considered safety glass.

28.7.4 Tempered glass

Tempered glass is most easily distinguished by its breaking

characteristics. When tempered glass breaks, it breaks into

small cubical or rounded pieces, not into shards of glass.

Tempered glass is created through a re-heating process

during its manufacture. Tempered glass is considered safety

glass. Because of its breakage characteristics, and because

it resists impact better than float glass, tempered glass is

required in many locations in the built environment where

human impact contact is a possibility. This includes

locations near the handles of doors, and where kicking may

inadvertently occur. Tempered glass is much stronger than

float glass, by approximately four times. After glass has

been tempered, it cannot be cut or drilled (or deeply

etched). Any of these activities must be anticipated and accomplished prior to the glass being

tempered.


28.7.5 Wired glass

Wired glass is most commonly used in fire-rated assemblies. Wired glass receives its descriptive

name due to the wire mesh that is embedded in its centre. This wire mesh helps the glass

withstand both impact breakage and helps the glass retain it's shape and integrity in the case of

excessive heat. Wired glass cannot be tempered. Other types of glazing can be used in fire-rated

situations, including many newer products such as gel-filled glass and a clear ceramic material.

The building official must always be consulted in the proposed use of special or newer products

in fire-rated situations.

28.7.6 Glass block

Glass block is typically found with masonry

products in its classification, but is included here

for it's potential use in glazed opening situations.

Glass block is available in several standard sizes

and is installed with either a mortar or silicone

system. Glass block may be clear or with many

different available patterns, the level of visual

privacy can be adjusted greatly with appropriate

selection of glass block. Because of the

construction of individual glass blocks as well as

the installation method, glass block provides a

higher degree of acoustical privacy than other

forms of glazing.

28.7.7 Insulated glass

Insulated glass refers to two or more sheets of

glass that are separated by a sealed air space.

Double-glazing is typically insulated glass, as is

triple glazing. The incorporation of a dead air

space between the sheets of glass improves

thermal performance and reduces condensation on

the face of the glass. There are varying

thicknesses of insulated glass; typically the

thickness is dependent on the width of the air

space incorporated. Sometimes an inert gas

replaces the air in the space between the sheets of

glass to improve thermal performance even more.

28.7.8 Curtain walls

Curtain walls refer to exterior walls consisting of metal framing and either glass or spandrel

panels. Curtain walls are typically not load-bearing walls, and create a 'skin' for the building.

There are several methods of assembly for curtain walls, each refers to the major components

used to frame the glass.


Lesson - 29: Application of Glass in Interiors

Objective:

To study the role of glass in interiors

Structure:

29.1 Introduction

29.2 Solid glassware

29.3 Ultraviolet Glass

29.4 One-Way Vision Glass

29.5 Armour Plate Glass

29.6 Decorating Clear Glass

29.7 Stained Glass

29.1 Introduction

"A man who looks on glass, on it may stay his eye, or if he pleases through it pass, and then the

heaven espy."

Apparently fragile, yet structurally capable of supporting its own weight in quite large areas,

glass is as ethereal in quality as stone is solid, or steel strong. A beautiful and interesting material

affording boundless possibilities, it can be obtained in transparent form, many different

translucent or opaque grades, and in any number of colours in addition to the more common

clear form. Technology has developed it until properties have been introduced to enhance its

natural advantages and modify some of its disadvantages, which are of paradoxical nature. For

example, a large area of glass reveals a fine vista to advantage, but often cancels out privacy. It

may induce far too much warmth when heat is present and be too cold when it is absent.

However, you may have privacy without loss of light, and openness through an expansive

interior, yet highlight certain spaces.

29.2 Solid glassware:

Solid glassware features are decorative and so are different methods of treating glass surfaces.

Glass can be fluted, reeded, rough cast or feathered. If possible get a sample box or call in at a

specialist dealing in glass and mirror ware, and look at the 'rolled' glass, impressed on one side

with parallel ribs, the 'cathedrals', which have ripples or dimples on one side, wired 'Georgian'

glass with mesh reinforcement used for fire regulation purposes, and 'prismatic' glass which

directs light specifically in one particular direction. This is helpful when you either want to

increase the lighting in an obscure area, or deflect glare from direct sun.

29.3 Ultraviolet Glass:

There is ultraviolet glass, more usually placed on the external facade to allow the passage of

ultraviolet rays which are blocked by normal glass. While this is expensive, it is of great benefit

to the unadventurous sunbather - although in these days of ozone depletion one must not forget


the risk of skin cancer in spending time behind a sheet of glass which admits ultraviolet light

when one is more used to being 'safe' behind conventional glass. There is also heat-absorbing

glass that reduces the infra-red radiation of a strong sun and therefore keeps a room cooler and

helps prevent fabric fading without losing any natural light. In addition one can find anti-sun

glass which absorbs the heat through a cool blue/green glass, and fire-resisting glass which has

an electro-copper glazing of decorative quality.

29.4 One-Way Vision Glass:

To be effective, one-way vision glass has to have a higher illumination in front than on the

reverse side, otherwise it just reverts to silver striped glass on both sides. It is often asked for in

hospitals and shops, to allow, for instance, the occupant of an office to see customers or patients

without being seen, and should be considered very carefully in conjunction with the appropriate

lighting.

29.5 Armour Plate Glass:

For doors and shelves, counters and showcases, armour plate glass is essential for strength. It

must not be cut, drilled or worked in any way on site and is supplied in certain specific sizes.

Any decoration that is required has to be done prior to processing; otherwise, if by position and

clarity it constitutes a danger, with people crashing into it (and it does happen!) then some form

of protective timber, metal slatting or stencilled motif would help prevent this. It must be

remembered, however, that one of the difficulties of any form of 'sticking' or 'painting' on glass is

that the reverse side will also be seen on a free-standing form.

29.6 Decorating Clear Glass:

Unless the glass concerned is used for wall panels or wall finishes, where a glossy black or

mirrored 'silvered' glass is more effective as it does not reveal the backing, it is better to decorate

clear, plain glass sensitively, by various means such as the following:

Acid Embossing: Acid embossing dissolves or etches the surface, which then becomes frosted

when an alkali such as soda is applied. The concentrations and applications can be varied, and

therefore in the hands of a really skilled craftsman or artist, very attractive and effective designs

can be accomplished. Graphic designs are often carried out with this method, in which case the

reversed side of the glass is etched and illuminated by suitable lighting to give the desired effect.

Gilding or silvering may also be used for added emphasis and decorative richness, and the

interplay of different textures in gold or silver can create a design of considerable subtlety and

interest.

Wheel cutting: Wheel cutting is literally like drawing direct but with an abrasive wheel of

different cutting edges, which make various types of incisions in the glass. A tremendous variety

of effects can therefore be gained, and provided the decorative quality of the glass is enhanced

by the cutting and design, both elegant and decorative qualities result, besides creating a partial

obscurity.

Sandblasting: Sandblasting can be used on transparent and opaque glass and can result in fine

lines, flat areas or modelled effects. These are created by particles of sand and similar substances

being fired at high speed at the surface, which can be taken down to as much as one third of the

thickness of the glass. This method is also used to create a key for other finishes such as enamels,


and for cutting awkward pieces. Deep, light and shaded sand blast are the basic types of texture

that can be obtained.

Edge Finishing: Finally, glass can be finished around the edges in a variety of ways, set into

frames and fixed with adhesives or, for large areas, clips. Screws can also be used, set into

collars of fibre, rubber or metal, and protruding sufficiently to avoid the screw 'pinching' into the

glass. Insulation must always be provided between metal clips and silvered mirror to avoid

corrosive interaction between them.

Made by grinding or wheel cutting, the popular bevelled edge can be a straightforward slant

from front to back, or mitred at 45 degrees, 'feathered' with an obtuse angle, or finished with a

very steep angle from front to back. Otherwise the normal arris edge can be rounded in several

different profiles.

Combined with areas of structural interest, or groups of accessories, beautiful effects can be

gained from plain and simple glass or mirrored sheets. However, there are certain points that

must be remembered. When mirrored glass is being used it is important to ensure that ugly

background items are not unwittingly reflected, thereby destroying the enchantment. Nor should

strong lights be directed at them, so that they glare unceasingly and create visual discomfort.

Also, if special anti-glare or tinted glass is used for filtering heat and sun through the external

facade, then colours and textures may well be affected by this, and should be adjusted

accordingly. The same applies if tinted or coloured glass is used in light fittings themselves,

since it will ultimately affect their brilliance and performance and cast coloured light onto fabrics

chosen in different conditions.

For flattering complexions, pale pink tinted mirrors are helpful as opposed to the pale blues,

greens and ambers which make people look sallow. Pink can create a glowing atmosphere for

exclusive restaurants, ballrooms and their adjoining powder rooms.

Although glass is relatively inert it can be seen to bend under pressure, and does expand and

contract. Therefore it must be set in rubber, wash-leather, foam rubber, plastic, felt or velvet,

even though weathering mastics are obviously not necessary internally, to protect the glass from

shattering or rattling and to allow tolerance of movement between the glass and the frame.

It is also important to keep to the ratios of size/thickness/weight recommended by the

manufacturers, and to ensure that mirrors are set in adequate damp-resistant conditions with

shatter-proof spacers behind. Otherwise glass and mirror will be found to be resistant to most

chemicals and dirt, and yet easy to clean if necessary. Impermeable and not abrasively

vulnerable, it is a hard and sparkling material to use on walls and ceilings, and for suspended

free-standing items and sculptures.

29.7 Stained Glass

Stained glass is another attractive material that not only has its

own beauty, but can, by luminous reflections in adjacent

materials such as tiles, metals, marbles and gloss paints, add

considerably to the charm and richness of the interior. For

proper effect it must be combined with light and, if used in

internal/external viewing position, it must look well with the

rest of the external facade.


It is normally made of numerous pieces of coloured glass, rather like mosaics, set into lead strips.

There is a tendency for stained glass to bend under pressure, and therefore if reinforcing rods of

iron or copper are incorporated it is better if these can relate to the design in some way.

There are also interesting stained glass and concrete screens that can be designed for impressive

areas if they do not need to be lit extensively by natural means. Since the thickness of glass is

embedded into plaster or a concrete free-standing frame, it tends to assume a rather more solid

appearance.

Antique glass, that has the 'bull's eye' shape and uneven texture of the first window glass ever

made, can be introduced into such features if desired. Indeed, techniques have been developed

where actual coloured pieces can be fused or stuck onto a large plate glass window, in a random

but balanced 'glass mural' either framed and free-standing or fixed to a suitable backing on a

wall, and again properly lit to show its quality to advantage.


Lesson - 30: Glazing

Objective:

To study about fixing of glass.

Structure:

30.1 Introduction

30.2 Frames and Operation

30.3 Code Considerations

30.1Introduction

Glazing on a project may be found in several locations, in exterior walls as windows or curtain

walls, on the roof as skylights, in interior walls, and in doors and sidelites. Regardless of the

ultimate location of glazing, considerations involved in the design and selection of the size and

type of glass remain basically the same. Issues of heat gain or

loss, visual and acoustical privacy, view, security, and code

considerations all enter into the design decisions. We will discuss

these issues and further our understanding of types and

terminology involved in the subject of glazing.

30.2 Frames and Operation

Glass may be set into frames or it may be installed with a

frameless technique. Wood, steel, and aluminium are the most

common materials for framing glass. Each has specific unique

characteristics that are explained in more depth in the 'Frame

Types' section of this module. Regardless of the frame material,

there are some common features when glass is set into a frame.

The glass does not actually rest on or directly contact the frame

material, but rather is set onto setting blocks. Glass, wood, steel,

and aluminium each have different expansion and contraction

coefficients when exposed to heat and cold. A fixed connection

directly between the glass and frame material could cause the

glass to crack or otherwise break.

Windows may be fixed or operable. Operable windows are

selected when ventilation and/or communication are important

characteristics. Operable windows are available in several

standard types. Most common are single- or double-hung,

casement, awning, and horizontal sliding. Each of the operation

types has advantages and disadvantages based on the specific installation and location. The

actual mechanism for operation is often one of the disadvantages to an operable window. When


specifying, be sure to consider the strength of the individual who will be opening the window for

single- and double-hung and for horizontal sliding windows. In the case of a person with

impaired hand or arm strength either due to young or old age or a disability; or for those with

limited mobility of fingers or hands the sliding varieties (whether vertical sliding or horizontal

sliding) may need extra design considerations. With casement windows, often the crank for

opening is replaced with a 'butterfly' knob to allow window treatments to fall into place

completely. If the windows are exterior, consideration must be given to their proximity to a

walking path, as both awning and casement windows extend outward from the building face.

30.3 Code Considerations

Building and life safety codes articulate specific

requirements for location, type, and size of glazing.

When we keep in mind that each of the codes has the

primary purpose of safeguarding the health, life, and

safety of building occupants, the variety and

comprehensive nature of requirements for glazing make

sense.

Glass lites within doors are allowed in certain situations

as defined by code. A 20-minute door (designed for a

one-hour interior wall)

may have glass lites

installed, as may class B

1-hour and 1 1/2 hour doors. Class C 3/4 hour doors (designed

for a one-hour interior wall) may also have glass lites. In each of

these situations the actual type of size of glass is restricted. You

must check the governing codes in effect for the specific project

location.

Fire-protected windows can be a part of a door assembly (such as

a sidelite or transom) or can be a separate entity within a wall.

The rating required for a fire-protected window generally

depends on its location

within the building. The

glass, frame and

hardware all become a part of the rated window

assembly. The glazing within fire-rated assemblies is

restricted in size (usually not more than 100 sq. inches in

a fire-rated door) and type (fire-rated glass). Fire-rated

glass includes wired glass, specialty fire-rated glass

(such as ceramic or gel-filled), and in some special

situations, glass block.

Egress is another concern governed by codes. In sleeping rooms, windows provide a secondary

means of egress for occupants as well as entry for fire fighters. As such, their position and size

are very important. These windows must conform to several requirements: they must be at least

5.7 sq. ft. in area, must have a minimum clear height of 24", a minimum clear width of 20", and


the sill cannot be higher than 44" from the floor. If the egress window happens to be below the

ground level, there are also requirements for window well sizes.

If a window is in a location or of a size that it may be mistaken for a door, safety glazing is

required. If glazing is located within 24" of a doorway and is less than 60" above the floor it

must be safety glazing. This ensures that if a person misses the door and accidentally pushes on

the glazing, that they will not be injured. Safety glazing is also required if all of the following

four conditions are present: 1) glazing of more than 9 sq. ft.; 2) bottom edge is less than 18"

above the floor; 3) top edge is more than 36" above the floor; and 4) one or more walking

surfaces is within 36" horizontally of the panel. Safety glazing is also required for bathtub and

shower enclosures, pool and spa enclosures, and for glass railings. Glass railings must be fully

tempered or laminated heat-strengthened glass to be structurally adequate.


Summary:

This unit include the study of various types of glass available in the market like:

Sheet and plate

Waxed and laminated

Coloured

Insulating

Heat resistant and

Glass blocks.

Study of properties, sizes, prices various types of glass.

Role of glass in a decorating scheme.Glass products like furniture, stained glass, painted glass,

etched glass etc.Edge treatment of Glass like bevelling, grinding etc.Detailing

Basic Fixing – with general information on putty, beading, pliers and round cutting blade, etc

Leaving allowance for expansion and contraction while fixing in a frame. Etc.

Revision points:

1. Role of glass in a decorating scheme.Glass products like furniture, stained glass, painted

glass, etched glass etc.Edge treatment of Glass like bevelling, grinding etc.Detailing

2. Basic Fixing – with general information on putty, beading, pliers and round cutting blade,

etc

3. Leaving allowance for expansion and contraction while fixing in a frame. Etc

Key words:

Glass: - may be defined as a hard , brittle, transparent or translucent material chiefly composed

of silica, combined with varying proportin of oxides of sodium, potassium , calcium , magnesia

iron and other materials.

# For the manufacture of glass two type of furnace are used

1. Pot furnace

2. tank furnace

Glass fibres: - are made by letting the molten glass drop through tiny orfice and blowing with air

or steam to attenate the fibre.

Stained glass: - Stained glass is another attractive material that not only has its own beauty, but

can, by luminous reflections in adjacent materials such as tiles, metals, marbles and gloss paints,

adds considerably to the charm and richness of the interior

Intext Questions:

1. Explain in detail the structure of glass.

2. What are the properties of glass?


3. Discuss in detail the essential requirements of commercial glass.

4. Explain in detail the various categories of glass based upon its composition.

5. Explain any five types of special glass in detail.

6. Give a detailed account of the application of glass in interiors.

7. What are the various methods of decorating clear glass?

8. What points would you keep in mind while installing glazing in any building?

9. Explain the following terms:

a) Annealing

b) Curtain wall

c) Double Glazing

d) Float glass

e) Heat-Strengthened Glass

Terminal Exercise:

Students have to carry out a market survey on the various types of glass and glass products

available in your area. Keeping in consideration the properties, sizes and prices of various types

of glasses.


Prepare a detailed report highlighting the cost, materials, and availability of glass products in

your area, in report students should also include the Detailed description about the Basic Fixing

of glass– with general information on putty, beading, pliers and round cutting blade, etc

Supplementary materials/suggested reading:

1. Manufacturer‟s Details

2. Engineering materials (Surendra Singh)

3. Relevant I.S.Codes

4. Building Construction (Mackay, 4 Volumes)


Lesson - 31: Metals

Objective:

To study the various types of metals used in interiors and their properties.

Structure:

31.1 Introduction

31.2 Ferrous Materials

31.1 Introduction

Cast and wrought work, firm and strong in itself, turns functional items into works of artistic

interest. Duct and grill covers, floors, walls, ceilings, staircases, panels, fireplaces etc. are just

some of the areas which can be enhanced by this versatile material. Then there are door

surrounds, light fittings, furniture trimmings... the list is enormous.

Scintillating and glowing in various degrees of reflective finishes, smooth mounted sheets

create effects more subtle than mirror glass, blurring and blending metallic reflections into

stronger depths and brighter highlights. Elaborately etched, beaten or embossed panels, polished

or perhaps enamelled, can serve a functional as well as a decorative purpose.

Finally the small, often solid or composite cast items that can be made as ornamental features in

addition to being necessary items of hardware, all contribute to the contrasting gleam that is so

necessary in most interiors to enliven and maintain their interest.

Metals do not necessarily harden the atmosphere or create a clinical environment; but if that

effect is required then metals and plastics among other things can combine beautifully and

elegantly to create just that. There is no need for harshness or crudity of detailing, although all

too often this is in people's minds when they condemn the so-called 'modern' materials.

Therefore it is important to appreciate fully the qualities that such materials can afford.

Developments in recent years in the plastics field have been involved in improving their overall

strength after processing and moulding. It is now possible to obtain plastics with all their

advantages of fluidity and lightness and increase their strength so that they are comparable to

metals. As you can imagine, this has important and far-reaching implications, although one

always has to temper new discoveries and research with a certain amount of caution. The

behaviour of new materials or newly imposed properties on existing materials must be at least

as satisfactory as well-established and well-tried materials. These are already covered by British

Standards, Codes of Practice and other yardsticks adopted throughout the world. Since these

outline criteria of minimum performance requirements, anything below these values would not

be reaching satisfactory standards.

The term 'metal' has been used generally, being intended to cover both those ores that are mined

and the metal by-products that are subsequently separated in the purifying process.


31.2 Ferrous Materials

The ferrous metals are iron base metals which include all varieties of irons and steels. These

metals go a long way in bringing prosperity to a country.

Ordinarily, the terms, iron, cast iron and steel in reference to a metal in which the element iron

(Fe) is the major element do not refer to a specific metal or alloy, but are loosely used to indicate

a general type of iron alloy. The term iron should be used only when reference is made to the

element iron (Fe). In speaking of the commercial forms of iron such terms as Pig iron, grey cast

iron, wrought iron etc. may be used. Each of these terms represents some commercial form of

element iron, and each form may occur in many variations of chemical composition which

influence the functions within each class. Due to tremendous production tonnage of these metals,

and to their many forms and varied uses, a detailed study is not a simple and easy task.

Steel (master metal) is obtainable in great quantities, both in

wrought and cast form. Its plasticity, whether at room temperature or

at elevated temperatures, allows it to be worked either hot or cold. Its

combination of strength with plasticity makes it the most important

metal for use in large structures. By varying the carbon content and

by suitable heat treatments, we can alter the properties from a very

soft, workable steel of the type used, in pressed metal parts, wire and

similar materials to a hard, strong steel suitable for use in tools and

machinery where great strength and hardness are required.

Wrought iron is the oldest form of iron made by man. It was originally produced by slow

reduction of the metal from the ore in the forge fire. This reduction process resulted in a very

impure iron which required further refining by mechanical working, that is by hammering or

shaping to the form in which it is used. Wrought iron is a metal containing high purity iron and

iron silicate in physical association. It is very low in carbon and the iron silicate or slag is

distributed throughout the base metal in fibres which gives it a woody or fibrous appearance

when fractured.

Cast iron is fundamentally an alloy whose chief elements

are iron, silicon and carbon. Irons are available with a wide

range of properties. Pig iron, grey cast iron, white cast

iron, chilled cast iron and malleable iron are all referred to

as cast iron, chiefly because these forms of irons are not

plastic enough, even when hot to be forgeable; therefore

they are always produced commercially by a process of

melting and casting into shape, the commercial form of

each of these metals is in castings.


Lesson - 32: Aluminium

Objective:

To study the role and properties if aluminium used in interiors

Structure:

32.1 Introduction

32.2 Use of Aluminium in Interior Design

32.1 Introduction

Aluminium is relatively soft, non-magnetic and much less dense than brass or copper. Silvery in

colour, it has a wide range of uses and can be easily worked. Extruded, pressed, forged, drawn,

moulded, stamped, bent, hot- and cold-rolled, and shaped, it is attacked by alkalis and weak acids

but inert to sulphur. It does not interact with zinc, magnesium or cadmium, but has to be

insulated from other metals. Zinc and copper can be used as alloy elements which affect the final

properties of the metal, that can then be brazed, welded, rivetted, soldered or joined by

adhesives.

32.2 Use of Aluminium in Interior Design

Although aluminium has been known since at least 500 BC, and is quite a common element of

the earth's resources, it has been relatively recently used in the fields of architecture and interior

design. Since the mid 1920s ornamental grille work, balustrades and railing, windows, doors,

meshwork, chain curtains, screens and panels, plain, patterned or enamelled, have been

incorporated into sympathetic schemes in many types of buildings. Moreover, wall and acoustic

tiles, Venetian blinds and decorative rolling shutters and duct covers are items also normally

available in standard components and castings, which vary considerably due to specific

treatments and processing conditions.

There are certain different names and definitions for this metal around the world, so you should

check every aluminium product under consideration for exact properties and suitable uses,

getting the latest information from the manufacturers.

Chemical action may occur between aluminium, wood, masonry and mortar in certain

conditions, and therefore the metal needs special treatment or a protective membrane to prevent

it being affected detrimentally, or indeed causing problems itself.

As always, when designing something purpose-made, you should bear in mind how the item is

going to be dealt with while being made in the workshop, then in transportation, and finally

during its assembly on site. If it is not possible to use standard component parts, then one must

understand the limitations on size that the various finishing processes impose. It will always be

easier to ensure a satisfactory design both aesthetically and technically if all the separate parts


are arranged to fit together easily and compatibly with rhythm and balance between the joints.

Otherwise untold difficulties and expenses are likely to occur.

Any moving parts that are likely to rub against each other should be designed with separators or

spacers to avoid the coating being undermined. If aluminium panelling has to comply with fire

requirements then it has to face composite panels of suitable backing and core infill, since it has

a very low melting point. Otherwise this has to be combated in some way by a toughening up

process. Aluminium foil, however, is used successfully for insulation in composite panel form

but expansion joints as always have to be included.

The various finishes for aluminium, which also apply to other metals, include grinding,

polishing, scratching, sand-blasting, embossing, chemical finishes (developed especially for

aluminium) and the more expensive but most effective and satisfactory electrochemical and

anodized finishes. It is possible to create metallic colours with this treatment; other interesting

finishes that can be obtained are opaque, translucent or glossy, and in varying degrees of

reflectivity. Surfaces that have been prepared can take other finishes such as porcelain, vitreous

enamel, paints and lacquers, or be electroplated with another metal. The finished surfaces must

be cleaned by the correct methods and cleaning agents to avoid undermining the effects.


Lesson - 33: Other Metals

Objective:

To study the various types of metals used in interiors and their properties.

Structure:

33.1 Copper

33.2 Brass

33.3 Bronze

33.4 Antimony

33.5 Chromium

33.6 Gold

33.7 Silver

33.8 Nickel

33.9 Stainless Steel

33.10 Metal Finishes

33.1 Copper

Copper is an extremely important historical metal, used extensively in the past, both in the

Mediterranean world of the Ancients, and China and India, and later in Central America and

Peru. It is a rich-looking and non-magnetic metal, with a reddish-brown colour that is bright

when polished but has a protective green patina (verdigris) when allowed to tarnish (oxidation

caused by interaction with the oxygen in the atmosphere). It can be welded, brazed and soldered

and is an excellent conductor of heat, although it must not be allowed to come into contact with

steel, aluminium, zinc, magnesium or stainless steel as it will corrode them. Also in damp areas

there is a tendency for it to affect some building materials and cause staining, so care has to be

taken with its installation.

Copper can be cast, drawn, extruded, spun, hammered, punched, or worked hot or cold, and,

being an excellent conductor of electricity, is often used as a base for other metal plating,

including chromium and silver. Woven into wire cloth or

mesh, it is ideal for flame-proof vents, grilles and screens. It

is also the main ingredient for several other alloys (mixtures

of more than one metal) such as brass and bronze, which are

equally attractive in their form, but different in colouring. In

sheet form there are many uses for copper, including facing

counters, forming light fittings and edging display cases, for

example, although expansion can be a problem, as it does

have a high coefficient of expansion when heated. It is

attacked by alkalis and many acids, but resists sea air well.


33.2 Brass

Brass is mainly a mixture of copper and zinc, which vary in

proportions and thereby affect the colour of the resultant alloy,

which can be from a very light yellow to a dark golden colour.

Not as strong or as hard as iron-based alloys, it is easier to

work and resists corrosion better. It must not be placed in

contact with iron, steel, stainless steel, aluminium, zinc or

magnesium if there is a risk of galvanic action. It is used for all

types of decorative doors, fittings and trimmings for

architectural details such as doors, windows, counters and

furniture. Brazing is a normal method of joining, besides

welding and soldering, and polishing is used to obtain the

bright sheen that is so attractive.

33.3 Bronze

Bronze is very similar to brass and can be rolled and extruded,

forged and cast, since it is dense, hard and corrosion-resistant.

Bronze and brass sometimes get confused in annotation, but

tin rather than zinc is the main ingredient mixed with copper

to produce bronze, and it is a darker, redder material than

brass.

There are simulated bronzed finishes that will be discussed

later, but the main architectural ideas for this somewhat

difficult to work and expensive material are tiles, plaques,

screens and ornamental grilles. Sculptures, both free standing

and as murals, whether cast, forged or extruded, can be

impressive as focal points in prestige buildings.

33.4 Antimony

Antimony is primarily important these days as a fire-proofing element and as an ingredient for

paints, enamels and lacquers, although it is strictly a metal, and was used as such by the

Chaldeans as long ago as 4000 BC. In view of its modern use it will be referred to later in the

'Applied Finishes' section, together with titanium, and zinc, which in solid form is only used

internally for very functional positions such as ducting.

33.5 Chromium

Chromium (Chrome) is associated with the modern interior more than any other metal. Capable

of a brilliant sparkling finish, it is generally speaking non-magnetic and oxidation-resistant,

sheds water well and does not tarnish in air. While it can be cast and hot-forged, it is too brittle to

be worked cold. Besides being useful in non-ferrous alloys, it has increased in use and

importance as ferro-chromium in cast iron, alloy and stainless steel.

Although there are several methods of producing chromium commercially, the processes are

expensive and specific. Whether it is to coat alloys or ferrous metals, to be completely protective

the coating needs to be of ample thickness, preferably with a coating of copper, or nickel, or


both. Again, you may find dimensional limitations in the processing plant, so that if a particular

design is envisaged, discussions in order to understand the possibilities are imperative.

The resultant attractive steel-white, water-resistant surface, if handled properly in the interior, is

well worthwhile, however, giving an elegant and sophisticated appearance. For a firm chance of

continuing satisfaction, small types of items, trimmings, furniture, framing, counters, display and

bar details, bathroom fittings and light fittings are recommended, particularly as these will show

off its qualities to best advantage.

33.6 Gold

Gold is known to everybody in some form or another, but is very limited for decorative use in

interior work due to its cost and availability. It is most malleable and ductile, and can be rolled,

drawn, spun, hammered and cast. It has a special lustre and pleasant colouring which varies in

tone from a white, bright yellow to a reddish blue gold. It is

corrosion-resistant to air and not attacked by acids, having

itself a great chemical stability.

Used to plate metals, it is chiefly found as a decorative finish

on interior fittings, and can be applied to brass, bronze,

copper, nickel and silver. Welding or soldering, but not

machining, are acceptable methods of joining. Gold leaf as an

applied finish will be mentioned later.

33.7 Silver

Silver follows naturally from gold, and is in fact the next easiest metal to work. Rolled,

extruded, spun, bent, drawn or hammered, it resists oxidation but tarnishes in a sulphurous

atmosphere. As it is more readily available than gold, usually the most beautiful accessories are

to be found in this whitest of metals. Constructionally arc welding or brazing are the normal

methods of joining this material.

While chrome affords much glitter if desired, and silver

conducts heat too readily to make it feasible for many fittings,

it is used extensively for mirrors. Therefore the use of silver

will depend a great deal on your purse and your imagination,

since the result of a repetition of design in silver would

enhance the quality to such an extent that rich furniture and

lavish furnishings would be needed to counterbalance the

effect. More usually a chromium or nickel alloy is likely to

substitute for the real thing

33.8 Nickel

Nickel was, like all the main metals, known to the Ancients in many parts of the world, who

worked with it to great effect. It is another silvery metal that takes a high polish, is corrosion-

resistant and also very valuable. Strong, like iron, it resists oxidation, strong alkalis and most

acids. When mixed with other alloys, which is usual, it therefore imparts its good qualities and is

much used in stainless steel and nickel silver, the latter being used for ornamental metal work,

bathroom accessories and fittings, food equipment, plates, silverware and white metal hardware.


It can be hot- and cold-rolled, bent, forged, extruded, spun and punched. For joining,

oxyacetylene, brazing and soldering are the main processes.

Electroplating is the commonest way to ensure a decorative and/or protective coating of nickel

which is imparted to other metals such as aluminium, copper, brass and steel. It can be given a

matt, satin or bright polished finish, and there is a limited colour range of decorative coatings. It

is also possible to get it co-deposited with other metals such as copper, where nickel-copper

combinations give various resultant tones of light golden colour. To get the desired effects,

however, very careful enquiries should be made concerning the possibilities afforded by such

processing developments.

33.9 Stainless Steel

Stainless Steel is part of the much wider and complex

subject of steel. It is itself a group of steels rather than

one in particular. However, this inexact term 'stainless

steel' has come to mean a smooth, gleaming, elegant

material that graces much of modern architecture, both

externally and internally, and gives a very satisfactory

performance and appearance.

Generally the term covers highly alloyed steels

containing more than 10% chromium, with nickel and

manganese as other important elements. Consequently they are resistant to heat, oxidation and

corrosion, and have special characteristics such as strength, toughness and ease of fabrication.

Although each different combination of alloys and elements produces steels that go into sub-

groups, they can all be cast, rolled, drawn, forged, bent and formed. Ribbed, corrugated sheets,

for example, are quite usual.

While joining methods vary according to the particular alloy, generally rivetting and welding are

used. Since stainless steel is very strong, a thinner gauge is possible than would normally serve,

but care has to be taken to ensure that distortion or surface flaws are not incurred.

It can be obtained in sheets, strip, plate and various forms including bars and square section, with

different types of finishes as required, and in different weights. Interior wall finishes, doors,

screens, trimmings, grilles, louvres and counter tops are common items found executed in this

worthwhile material; indeed it is also found in fitted kitchens, dairies and laboratories.

After the material has been installed it should always be cleaned down, since this not only leaves

it looking immaculate but helps the protective film of chrome oxide to form on the clean surface.

Care must be taken to provide adequate expansion joints in the fabrication to avoid distortion.

Despite its agreeable, highly polished and smooth surface, it requires very little maintenance.

33.10 Metal Finishes

These are the main metals you are likely to deal with as an interior designer, and to round off the

subject we include below an outline of the processes and equipment required to obtain the

various finishes mentioned above.

Roughing is a preliminary operation to prepare very scratched surfaces for polishing, which

may necessitate greasing, which is a 'refined' roughing done with a lubricant, before finally


buffing the surface with felt polisher and powder. If grease is added to this, the high speed soft

polishing wheels can get an even higher finish which almost makes the surface appear to change

colour.

Burnishing that substitutes for these processes produces a reasonable but inexact perfection of

high lustre finish.

When coarse- or smooth-lined surfaces or satinized, sheeny finishes are required, these can be

obtained through wire brush finishing applied with different thicknesses and at different angles

of application.

Sandblasting can also be used to give metals a surface texture, although this should be protected

by anodizing or lacquer to prevent dirt accumulating in the crevices.

Hammered metal can have the surface highlighted in order to emphasize the texture or pattern

produced, as can an etched surface that can have modulations of depth controlled and organized.

Metals that are to be painted are given suitable 'key' surfaces at the mill for better adhesion.

Metals themselves can be sprayed onto other metals and materials, although such coatings tend

to be porous. Such methods are dealt with in 'Applied Finishes'.

It is sufficient to say here that if you are considering using metals in the interior, use their

intrinsic qualities of reflectivity, whether they are dazzlingly bright or softly illuminated to

shimmer or cast a gentle sheen. It is with these and mirrored materials that optical illusions

combined with lighting techniques are intriguing. Unusual effects, fantasy environments and

highly original schemes are possible with metals. Besides this they are able to convey a feeling

of luxury with their quality and lustre.


Lesson - 34: Plastics

Objective:

To study the role and properties of plastics used in interiors.

Structure:

34.1 Introduction

34.2 Constituents of Plastics

34.3 Classification of Plastics

34.4 Comparison between Thermoplastic and Thermosetting Materials

34.5 Thermoplastic Materials

34.6 Thermosetting Materials

34.7 Properties of Plastics

34.8 Shortcomings of Plastics

34.9 Uses of Plastics

34.10 Commercial forms of plastics

34.10.1 Plastics sheets

34.10.2 Plastic Tiles

34.10.3 Plastic Laminates

34.10.4 Plastic Panels

34.10.5 Plastic pipes

34.1 Introduction

A plastic can be broadly defined as any non-metallic material than can be moulded to desired

shape. The most common definition for plastics is that they are natural or synthetic resins, or

their compounds, which can be moulded, extruded, cast or used as films or coatings.

Most plastics are of organic nature composed of hydrogen, oxygen, carbon and nitrogen. The

synthetic plastic development dates from 1900 when Dr. Beekland announced the production of

phenol formaldehyde. Since then several new plastics have been developed.

In order to give desired properties to the finished plastic articles, certain moulding compounds

like fillers, plasticizers, solvents, pigments etc. are added. The basic raw materials used in the

manufacture of plastics are generally obtained from the following natural substances:

i. Coal

ii. Petroleum

iii. Limestone

iv. Salt

v. Sulphur


vi. Air

vii. Water

viii. Cellulose from cotton and wood.

In the field of building construction, plastics have been found very useful for a variety of

purposes e.g. fittings, fixtures, structural component parts etc.

34.2 Constituents of Plastics

As earlier stated that the basic raw materials for producing plastics are obtained from coal,

petroleum, are and water. A moulding composition for plastics is prepared from the following

raw material groups:

1. Binder. Binders may be either resins (synthetic or natural) or cellulose derivatives

(polymeric compounds), chemically both kinds of materials may be described as

substances made up of compounds of very large molecular weight.

2. Fillers. The materials added to the plastics to improve their mechanical properties and to

make them economical are called „fillers‟. These are powder, fibrous and laminated

fillers.

i. Powder fillers: Quartz power, chalk, talcum and organic substances (ground saw

dust).

These fillers improve hardness, durability, heat resistance and acid resistance

of plastics and reduce cost.

ii. Fibrous fillers: Asbestos, wood wool, saw dust and glass fibres.

The increase strength, reduce brittleness and enhance thermal resistance and

impact strength of plastics

iii. Laminated fillers, Paper, cotton and fibre glass cloths, asbestos, card board and wood

veneer.

They increase mechanical strength of plastics. Asbestos and cardboards also

increase heat and acid resistance properties.

3. Plasticizers: The chemicals added to plastics to make them

soft: to improve their toughness at finishes stage and to

make them flexible are called plasticizers. A plasticizer

should be chemically insert, non-volatile and non-toxic.

4. Common plasticizers are: Vegetable oils, aluminium

stearates and dibutyl phthalate and camphor.

5. Colouring Matter. This is usually in the form of pigment

and dyes and often added to monomers and gives the

required colour to the plastics. The colouring matter should

be durable and adequately fast to light.

6. Commonly used dyes are: Organic (AZO dyes, anthraquinone vat dyes) and mineral

pigments (ochre, chromium oxide and ultramarine).


7. Lubricants. Common lubricants are: Mosallic soaps and stearates. They facilitate

moulding operation by increasing the flow of plastic mix in the die and also prevent

sticking of plastic to moulds.

8. Catalysts. These compounds are added to accelerate the chemical reaction during the

process of polymerisation of plastics. These compounds also act as hardners and

accelerators.

34.3 Classification of Plastics

Most commonly, plastics are classified into,

1. Thermoplastic Materials are those which soften on the application of heat, with or

without pressure and require cooling to be set to a shape.

2. Thermosetting Materials are those plastics which require heat and pressure to be

moulded into a shape.

The difference between thermoplastics and thermosetting materials may be explained in terms of

molecular structure. The thermoplastics are essentially long chain macro-molecules with a

limited number of cross links. When heated and compressed, the chains glide over each other

and fluid materials take the shape of any mould in which these are placed. The thermosetting

plastics are characterized by strong cross links between the chains; once these are formed by heat

and pressure, the plastics set to rigid infusible solid.

34.4 Comparison between Thermoplastic and Thermosetting Materials

Thermoplastic Materials Thermosetting Materials

They are comparatively softer and less

strong

They are stronger and harder than thermoplastic

resins.

They can be repeatedly softened by heat

and hardened by cooling.

Once hardened and set they do not soften with the

application of heat.

Objects made by thermoplastic resins

cannot be used at comparatively higher

temperatures, as they will tend to soften

under heat.

Objects made by thermosetting resins can be used

at comparatively higher temperatures without

damage.

They are usually supplied as granular

materials.

They are usually supplied in a monomeric or

partially polymerized form in which they are either

liquid or partially thermoplastic solids.

34.5 Thermoplastic Materials

Important thermoplastic materials are described below:

1. Polythenes: This material originated in England was produced commercially in United

States in 1943. Polythenes are obtainable as viscous liquids, gums and tough flexible

solids suitable for moulding.


They are wax like in appearance, translucent, odourless and one of the lightest

plastics.

Flexible over a wide temperature range.

High resistivity and dielectric strength.

Chemically resistant.

Do no absorb moisture

Dielectric losses and dielectric constant are low

They are relatively low in cost.

Uses

High voltage (up to 30 KV) applications

Coaxial cables.

Packaging

Moisture proofing

Coating ice-cube trays.

As insulation in submarine cables and radar lines.

2. Polyvinyl Chloride: The vinyl chlorides are formed from hydrochloric acid, limestone,

and natural gas or coal. The forms of vinyl chloride are almost unlimited.

Properties:

The Flexible types are strong, tear resistant, and have good aging properties.

The rigid types have good dimensional stability and are water resistant. They are

resistant to acids and alkalise.

It becomes soft beyond 80C

It is self-extinguishing when ignited and the source of lame removed.

The hard type of PVC is formulated with less plasticizer than the general-purpose

grade and shows less tendency to flow at high temperature which is an advantage

when the cables are to be laid in very hot surroundings.

Although its electrical properties are not so good as those of rubber, it offers more

resistance to oxygen, ozone and sunlight.

Uses:

Cable jackets

Lead-wire insulation

Rubber substitute

Fabric Coating


3. Silicones: The basic ingredients of silicones are silica and coke which are mixed and

placed in an electric furnace. The silica is reduced to silicon, which is one of the starting

materials. The other reactant is methyl chloride, prepared by chlorinating methane gas.

The two reactants are mixed in a react at a high temperature and moderate pressure, using

copper as a catalyst. The desired products are then hydrolysed and condensed to form

silicon polymers.

Properties:

They are a chemical hybrid, a cross between organic and inorganic materials.

They hare both the stability of inorganic products and the versatility of organic

materials.

As a moulding compound they have good dielectric qualities and the ability to

withstand high temperature (upto 260C)

They are mechanically weak and have poor chemical resistance.

They are water-repellent.

Uses:

They are used as high heat resistant insulators.

4. Polystyrene: A high strength plastic is obtained by copolymerisation of styrene with

butadiene and then blending with natural or synthetic rubber.

Properties

Moisture-resistant

Low dielectric constant

High resistivity

Adequate chemical resistance.

Uses:

Lenses

Refrigerator-cabinet compounds.

Radar components

Electrical insulation

Instrument panels

5. Polyvinylidene Chloride:

Properties:

Acid resistance

Toughness

Non Flammability


Solvent resistance

Uses:

Seat covers

Belts and gaskets

Woman Fabrics

Acid-resistant tubing

6. Bitumen:

Properties:

It is the oldest known plastic and has been employed since 3000 B.C.

The bitumen plastics of today are made from bituminous products by mixing with

a suitable filler, such as slate dust or asbestos in powder form

They have good electrical insulating properties.

Uses:

They are uses for battery-cell plugs, stoppers, electrical mouldings of the cheaper class

etc.

34.6 Thermosetting Materials

The important thermosetting materials are described below:

1. Aminos: these are of two types:

a) Urea Formaldehyde Resins:

Properties:

They are derived from the reaction of urea with formaldehyde or its polymers.

These resins cannot offer resistance to heat

Uses:

They are employed for high voltage application. They are also widely used in

making ballpoint pen barrels, electric mixer housing, cosmetic cases, distributor

heads etc.

b) Melamine:

Properties:

They are derived from a reaction of dicyandiamide with formaldehyde.

When the resin is used with asbestos or glass fibres as filler material, its heat

resistance is in the range of 2000 degree C.


Adequately resistant to Chemicals.

Outstanding electric are resistance

Excellent resistance to water

Available in a full range of translucent or opaque colours.

Uses:

Due to arc resistance they are widely used in electrical field particularly for such

parts as distributor housings.

They are extensively in treating paper and cloth to impart water-repellent

properties and in producing laminates.

They are used for tableware (but they are stained by coffee) Amonos are used in

all types of electrical items such as shades, switches, white plugs etc.

2. Phenolics (Phenol – formaldehyde resins)

Properties:

They are made by a reaction between phenol and formaldehyde

They are probably the most widely used and cheapest of thermosetting plastics.

Strong, rigid and dimensionally stable

Heat and solvent resistant

Non-conductor of electricity

Uses:

They are moulded into television and radio cabinets, telephones, appliance

handles, electrical sockets etc.

3. Epoxy Resins:

Properties

Epoxy resins is basically a polymer of epichlorohydrin and bisphenonl

They are transparent, light amber colour and have very little shrinkage.

As coating materials, they have shown superior toughness, elasticity and chemical

resistance.

As adhesive these materials have shown extremely high bond strength without the

need for pressure for curing.

Uses:

They are used as an insulating material in cable-end boxes, cable joint boxes,

instrument transformers etc.

They have also found considerable use as casting materials


34.7 Properties of Plastics

The plastics have a variety of significant properties. The properties common to most

plastics are given below:

Light weight

Low thermal conductivity

A wide range of colours

Resistance to deterioration by moisture

Low electrical conductivity

Fairly good resistance offered to attack by inorganic acids, bases and salts.

Plastics in many cases are non-inflammable, self extinguishing, and burn very

slowly

They are transparent, translucent or opaque.

Good dimensional stability

Good sound absorption properties

Bad conductor of heat

Good tensile strength

Can be easily fixed in position

Good resistance to peeling

Lack ductility

Quite Durable

Easy maintenance of plastic surfaces (do not require any protective coat of

paints).

34.8 Shortcomings of Plastics

Following are the shortcoming/limitations of plastics

Low heat resistance

Not very hard

Disintegrate gradually with the passage of time

Exhibit high creep

High coefficient of thermal expansion

34.9 Uses of Plastics

They typical uses of plastics in buildings are:

Electrical conduits


Electrical insulators

Floor tiles

Jointless flooring

Decorative laminates and mouldings

Bath and sink units

Foams for thermal insulation

Overhead water tanks

Roof lights

Wall tiles

Corrugated and plain sheets

Cistern ball floats

Lighting fixtures

Paints and varnishes

Water resistances adhesives etc.

Pipes to carry cold water etc.

34.10 Commercial forms of plastics

The important commercial forms of plastics used for civil engineering purposes are described

below:

34.10.1 Plastics sheets

i) PVC (Polyvinyl Chloride) Sheets:

PVC and its compounding ingredients are heated, masticated and then rolled into

thin sheets between heated rollers. The sheets are then annealed and after cooling,

they are rolled.

PVC sheets (generally kept 1 mm for economic purposes) can resist the effects of

grease solvent etc.

These should be laid only on dry surfaces, as they expand on being wetted.

ii) Fabric-backed sheets:

These are PVC sheets in which hession or felt is used for backing

These sheets are suitable for foot-traffic in dry conditions

iii) Polythene Sheets:

They are rough and water resisting: available in wide rolls and in varying

thicknesses.


They are used for sheltering materials from rain on building site and to assist

curing of concrete; also used as temporary covering for window and door opening

etc.

iv) Corrugated plastic sheets:

They are light in weight and fire resistant

Employed for roofing purposes in public buildings and factories

34.10.2 Plastic Tiles

i. PVC tiles:

These tiles are used for flooring etc.

ii. Fabric backed PVC tiles

These tiles are used for paving floors in dry conditions

iii. Thermoplastic vinyl tiles:

These tiles are manufactured from mixture of plasticised PVC, asbestos,

limestone and pigments.

They are suitable for heavy foot traffic in dry as well as in wet conditions.

They can be used both on wooden and concrete sub-floors.

iv. Polystyene wall tiles:

They are suitable for lining of walls of high class buildings.

34.10.3 Plastic Laminates

These are formed by impregnating sheets of fibrous materials such as paper, linen, canvas or silk

with a synthetic resin and then compressing the sheets together with application of heat. The

synthetic resin may be phenolic resin, urea formaldehyde or a vinyl resin. The resin is usually

dissolved in alcohol.

The material in roll form is immersed in the resin solution at atmospheric pressure and at room

temperature and then run through a drier at 150C. The rolls are next cut into sheets of given size,

which are arranged into stacks. These stacks finally are compressed in a hydraulic press at about

170C under pressure of 20MN/m2. The sheets are thus bonded to one another

Some of the important type of plastic laminates are:

i. Laminate bakelite

ii. Melamine surfaced phenolic paper laminates

iii. Polyster paper laminate

iv. Corrugated phenolic resin bonded paper laminates


Properties:

The laminated plastics have the following properties:

i. Light and strong

ii. Machineable

iii. Resistant to wear, acids and alkalis

iv. Impervious to water and oil

v. Have high dielectric constant

Uses:

The laminated plastics are used for:

i. Electric insulation

ii. Making silent gears

iii. Water lubricated bearings

iv. Pulley wheels

v. Pump parts

vi. Press tools

vii. Decorative purpose in wall panelling, translucent panelling table and counter

parts.

34.10.4 Plastic Panels

These are the sheets (3m x 1.5m x 25mm) made from special craft paper

impregnated with a phenolic resin

They are chiefly used for making light weight partitions

34.10.5 Plastic pipes

i. PVC Pipes:

They have good ductility

They do not burst due to freezing of water

Used for distribution of water, mine drainage, gas distribution etc.

ii. Polythene plastic pipes:

They have inherent flexibility and excellent resistance to breakage from

mechanical shock.

Suitable for water supplies, and for use in chemical and food industries.


Summary:

Unit discussed above includes the study of the properties and role of iron and steel used in

interiors, the advantages and disadvantages of using this material vis-à-vis other materials such

as wood glass and plastics, Aluminium used in interior Properties and usage of brass, silver,

gold, chrome and copper etc. in interiors. Types of finishes that can be applied to metals Role of

plastics in a decorating scheme. Plastic products like furniture, doors and windows etc.

Revision points:

The advantages and disadvantages of using this material vis-à-vis other materials such as wood

glass and plastics, Aluminium used in interior Properties and usage of brass, silver, gold, chrome

and copper etc. in interiors. Types of finishes that can be applied to metals Role of plastics in a

decorating scheme. Plastic products like furniture, doors and windows etc.

Key words:

Plastic: - are natural or synthetic resin, or their compounds, which can be moulded, extruded,

cast or used as film or coating

Thermoplastic Materials: - are those which soften on the application of heat, with or without

pressure and require cooling to be set to a shape.

Thermosetting Materials: - are those plastics which require heat and pressure to be moulded

into a shape.

Bronze: - Bronze is very similar to brass and can be rolled and extruded, forged and cast,

since it is dense, hard and corrosion-resistant. Bronze and brass sometimes get confused in

annotation, but tin rather than zinc is the main ingredient mixed with copper to produce

bronze, and it is a darker, redder material than brass.

Ferrous metal: -The ferrous metals are iron base metals, which include all varieties of irons

and steels. These metals go a long way in bringing prosperity to a country.

Intext question:

1. Where and how can you use metals in interiors?

2. What are ferrous metals? Explain in detail the various types of ferrous metals used in

interiors.

3. Write a detailed note on aluminium and its uses in interiors.

4. Discuss in detail any five types of metals which are used in interiors.

5. What are the various types of finishes which can be used for metals.

6. What are plastics? Explain in detail the constituents of plastics.

7. Write a detailed note on the classification of plastics.

8. What are the main advantages and disadvantages of using plastics in interiors?

9. Give a detailed account of the commercial forms of plastics.


Terminal exercise:

Students will study the properties and role of iron and steel used in interiors, the advantages and

disadvantages of using this material vis-à-vis other materials such as wood glass and plastics.


Students have to prepare a detailed study report about the properties and role of iron and steel

used in interiors, the advantages and disadvantages of using this material vis-à-vis other

materials such as wood glass and plastics and also have to give detailed description about Role of

plastics in a decorating scheme. Plastic products like furniture, doors and windows etc.


Supplementary Material / Reference

Books

1. Manufacturer‟s Details

2. Engineering materials (Surendra Singh)

3. Relevant I.S.Codes

4. Building Construction (Mackay, 4 Volumes



7. Trade magazines

Design Source and Material

Documents

Transcript of Design Source and Material