PROTECTIVE & DECORATIVE COATINGS:-

Special materials are used in the finishing coats of plastering or over the plastered surfaces to meet one or more of specific requirement such as decorative appearance, high durability,fire – proofing,heatinsulation,sound insulation,earlycompletion,high strength,etc..

Some of these special materials are given below:- Plaster of paris.

acoustic plasters.

granite silicon plaster.

Asbestos marble plaster.

keene’s cement.

Parian cement.

Snow- crete and colour crete cement.

barium plaster.

plaster’s putty.

PLASTER OF PARIS:- Quick-setting gypsum plaster consisting of a fine,

white powder, calcium sulfate hemihydrate.

Used since ancient times, plaster of paris is so called because gypsum was early used near Paris to make plaster and cement.

Plaster of paris is also used to hold parts of ornamental plasterwork placed on ceilings and cornices.

Used in medicine to make plaster casts to immobilize broken bones while they heal.

Some modern sculptors work directly in plaster of paris.

The speed at which the plaster sets gives the work a sense of immediacy and enables the sculptor to achieve the original idea quickly.

ACOUSTIC PLASTERING:-Acoustic plaster is plaster which contains fibres or

aggregate so that it absorbs sound.

Such plaster is applied in thicknesses of up to 1.5 inches. As compared with other sound insulation, it is easy to apply and is fireproof but it can be more fragile, being affected by physical stress and humidity.

Acoustic plaster is used in construction of rooms which require good acoustic qualities such as auditoria and libraries.

BARIUM PLASTER:- This is made from barium sulphate and is employed

as a final coat to the walls of X-ray rooms.

This finish acts as protection for the persons working in X- rays rooms as this surface absorbs the X-rays.

Walls can be covered with lead to give any desired protection and there is no better protection than this method can afford ,provided the lead has a sufficient thickness and is properly laid.

Barium plaster has been advocated as an X-ray protective wall material.

GRANITE SILICON PLASTER:- Granite is a ready-to-use render made

from a silicone resin mixed with

coloured quartz or marble aggregate.

The product is weather resistant, impact

resistant and washable.

This type of plaster possess the quick –

setting and highly elastic properties

This material therefore, when used in

plastering is not liable to crack.

It provides a hydrophobic layer that is

permeable to water vapour.

The product is available in three finishes:

Marble, Quartz and Natural.

ASBESTOS MARBLE PLASTER:- This is a mixture of finely crushed

marble,asbestos and cement.

It is used only for finishing coat,this

material presents a beautiful, marble

like finish.

A new plaster surface will give you 5 to

8 years of good service, depending on

chemical maintenance and is usually

the least expensive resurfacing option.

KEENE’S CEMENT:- A hard-finish gypsum plaster to which alum

has been added and which is used chiefly as

a gauging plaster in lime mortar for walls (as

of hospitals, stores, railroad stations)

It is plaster of paris which is calcined with

alum.

This material is the hardest form of gypsum

plaster and sets within few days.

It is white in colour and takes up a high glass

–like polish.

It is used for highly decorative plastering

work and ornamental work,due to its

polishing characteristics.

PARIAN CEMENT:- A hard finish plaster, similar to

Keene's cement plaster,

except borax is used as an

additive in place of alum.

It is also plaster of paris which

is calcined with borax.

It is also used for interior work.

This type of cement is

preferred for surfaces with

large areas.

SNOW- CRETE AND COLOUR CRETE

CEMENTS:-

These are the trade names given to

the white and coloured cements

respectively

White cement is used for both

external and internal works

Coloured cements are used for

finishing coat of external works

These coloured cements present a

decorative appearance to the

surface being plastered.

PLASTER’S PUTTY:-

This is prepared by slaking of pure lime with water,bringing it to creamy consistency,then straining it through a fine sieve and finally allowing it to evaporate until sufficiently stiff to use

It is normally used as a last coat to internal walls which are intended to be colouredlater.

their self-healing nature reduces cracking problems.

they can reduce condensation problems.

SIRA BITE:-

This material is obtained by slacking plaster of paris with petroleum

It is quick setting and gives a white hard surface on drying

It posses good workability and high fire resisting properties

It is used for plastering of internal work for fire resistant construction

SCAGLIOLA:-

This material is an imitation marble which is obtained by dissolving keene’s cement and colouring pigments in glue

This material is used for pilasters , panels , columns, etc.

Scagliola is a form of plaster, traditionally gypsum, which imitates decorative stone and has been widely used for the decoration of walls, columns, floors, fireplaces and table tops.

the use of scagliola is more commonly associated with the imitation of the finest marbles on a much larger scale, without any joints or defects, and for columns and pilasters in particular

THISTLE HARD WALL:-

This material is a product of high grade gypsum which has got the capacity of carrying sand

It sets rapidly and produces an excellent finish

It is normally used for internal work

High impact resistance and quicker drying surface. Suitable for application by hand, or mechanical plastering machine, to most masonry backgrounds.