Long Wall method of estimate

Estimating And Costing Exercise No. 2

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION 5

Exercise No. 2

1.0 Title:

TAKING OUT QUANTITIES FOR VARIOUS ITEMS OF WORK FOR LOAD BEARING

RESIDENTIAL BUILDING

2.0 Prior Concept :

Components of Load Bearing Residential Building, Unit of measurements of various items of work.

3.0 New Concepts :

3.1 Propositions

Proposition 1 : Quantity: -

It is an amount of work for a particular item which is measured in standard unit as per IS

1200 : 1958.

Proposition 2 - Long wall & Short wall method: -

It is a method of taking out quantities of various items of work in a load bearing structure.

The wall having longest length on plan is considered as "long wall" and all the walls parallel

to the selected long wall (irrespective of length) are also consider as long walls. The wall

perpendicular to the direction of long wall is considered as "short wall" or "cross wall".

The length of long wall is measured from out to out and the length of short wall, between long

walls i.e. in to in. Following formulae are used for calculation of length of long wall & short

wall.

Length of long wall = center to center distance between two end short walls + half breadth on

one side + half breadth of item on the other side

Length of short wall (in to in) = center to center distance between two end long walls - half

width of item on one side - half width on the other side.

FIGURE 3.1

Exercise No. 2 Estimating And Costing

6 MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION

For the above figure AB, DC and GH are considered as Long walls and AG, EH, GD, HF and BC are

considered as Short walls.

Length of Long wall L1 = AB = DC

= (0.3/2+4.0+0.3+6.0+0.3/2)+0.3/2 +0.3/2

= 10.90 meter.

Length of Long wall L2 = GH

= (0.3/2+4.0 +0.3/2 )+ 0.3/2 +0.3/2

= 4.6 meter

Length of Short wall S1 = BC

= (0.3/2+6.0+0.3/2) -0.3/2-0.3/2.

= 6.0 meter.

Length of Short wall S2 = AG =EH

= (0.3/2+4.5+0.3/2) -0.3/2-0.3/2.

= 4.5 meter

Length of Short wall S3 = GD=HF

= (0.3/2+1.2+0.3/2) -0.3/2-0.3/2.

= 1.2 meter

Proposition 3 - Center Line Method: -

In this method total length of centerlines of all walls, long & short, has to be found out. Find

the total center line length of walls (long & short) having same type of foundations and footings and

then find the quantities by multiplying the total center length by the respective breadth & the height.

In this method, the length will remain same for excavation in foundation, for concrete in foundation,

for all footings & for super structure (with slight difference when there are cross wall or number of

junctions).

For building having cross or partition walls, for every junction of partition or cross walls with

main walls, half breadth of the respective item is to be deducted from the total center length.

For building having different types of walls, each set of walls shall have to be dealt separately.

Find the total center length of all walls of one type & proceed in the same manner as directed

above, Similarly find the center length of walls of second type and deal these separately and so on.

For the above figure, all walls are of same type. So for determination of quantity, first find the

sum of center line of all walls.

Total Length of Center line = (2X10.60+3X6.3+1X4.3)-(4X0.3/2) meter.

= 43.80 meter.

Note :- Normally the quantities for building walls are calculated by long wall & short wall method.

PROPOSITION 4. - MEASUREMENT SHEET :-

Measurement sheet is a standard format for entering quantities of various items of work.

The format of measurement sheet is given below.



3.2 General Concept Structure :-

4.0 Learning Objectives:

4.1 Intellectual Skills:

(i) To develop ability to identity various items of work & their unit of meassurments in a

load bearing structure.

(ii) To understand the procedure of calculation of quantities of various items of work

in a load bearing structure.

4.2 Motor Skills:

(i) To develop ability to calculate the quantities of various items of work by entering

them in a standard measurement sheet.

Items of work and their units in a load bearing structure



Rules for deductions for opening, as per IS 1200 : 1958

(a) Masonry :-

No deduction is made for the following.

(i) Opening each up-to 1000 sq.cm. or 0.1 sq.m. (1 sq.ft.) .

(ii) Ends of beams, posts, rafter, purlins, etc. up-to 500 sq. cm. or 0.05 sq.m. (72 sq in) in

section.

(iii) Bed plate, wall plate, bearing of chajjas & like up to 10 cm (4inch) depth. Bearings of

floor & roof slabs are not deducted from wall masonry. For other openings deductions

are made as per the actual size of opening.

(b) Plastering & Pointing: -

Plastering usually 12mm (1/2") thick is calculated in sq.m. For walls the measurement

are taken for the whole face of the wall for both side and deductions for openings are

made in the following manner: -

(i) No deduction is made for ends of beams, posts, rafters etc.

(ii) For small opening up to 0.5 sqm. (5 sq ft) no deduction is made, and at the same time

no deductions or additions are made for jambs, soffits and of sills of there openings.

(iii) For openings exceeding 0.5 sqm (5 sq ft) but not exceeding 3 sqm. (30 sq ft.) Deduction

is made for one face only & the other face is allowed for jambs, soffits and sills, which

are not taken into account separately.

(iv) For opening above 3 sqm (30 sq ft), deduction is made for both faces of the openings,

and the jambs, soffits and sills are taken into account and added.

As the outer jambs, sills etc are much smaller than the inner ones; the deduction is

usually made from the outer face.

(c) White washing or colour washing or Distempering :-

Deductions are done in the same manner as for plastering.

5.0 Procedure :

Long wall and Short wall Method

1) Study the given drawing carefully.

2) Finalize the Items of the work with their units of measurements.

Prepare check list of items of the work.

3) Decide & mark the long walls & short walls on plan (Draw on separate page) as L1, L2, .

& S1, S2 respectively.

4) Calculate center to center distance of long walls & Short wall.

5) Write the detailed description of each item of work on measurement sheet.

6) Calculate the lengths of long walls & short walls separately for each item of work.

7) Enter the length, width/breath & depth/thickness (Height) in measurement sheet for each

item.

8) Calculate the quantity of each item of work & enter in measurement sheet.

Quantity = No x L x B x D.



6.0 Observation & Calculation

MEASUREMENT SHEET (Student to write description)

Name of work: .................




Name of work: .................



7.0 Result :-

The quantities of each item of work are calculated and entered against each item with units of

measurement.

8.0 Questions :-

Note : Distribute 3-5 questions to each student for writing the answers in the manual.

1) Calculate the quantities of following items by center line method. ( Refer

drawing given for long wall and short wall method. )

i) Excavation for foundation,

ii) Brick masonry in superstructure,

iii) Stone masonry in footing and plinth,

iv) Damp Proof Course

2) Prepare the Plan at following levels and show center to center distances for all walls

in the drawing given for term work.

i) Foundation level,

ii) Steps of footing,

iii) Plinth level,

iv) Roof level.

3) Calculate the quantity of door frame with frame size 10 cm X 7.5 cm and opening

1.0 m X 2.0 m with horn projections of 4 cm on both sides and floor penetrations of

4 cm on each side.

4) How cross walls affects the total length of center line in calculating the quantities by

center line method.

5) State the units of measurements of following items.

i) Sand filling, ii) Door and window shutter, panels, iii) Iron railing,

iv) Steel reinforcement.

6) State the different methods for taking out quantity of item of work ? which is the method

normally adopted in PWD .

9.0 Answer :-



(Space for Answers)

Long Wall method of estimate

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