Calculation Of Quantities Of Materials For Building Project
Bore excavation for 300mm diameter piers
This assessment involves calculation of quantities of materials of different elements of the building in project 1. There are nine tasks to be solved.
The summary of take-off quantities of materials s provided in Table 1
Diameter of piers = 300 mm
Depth of piers = 2.5 m
The piers are located at every corner/beam intersection and spaced at a maximum of 1800mm.
From the structural detail of the ground floor, the number of piers is 53.
The volume of one pier is calculated as follows: πr^{2}h (where r = radius of the pier and h = depth of the pier).
Volume = π x (0.15m)^{2} x 2.5m = 0.1767 m^{3}
Total volume of bored excavation for 53 piers = 0.1767 m^{3} x 53 = 9.366 m^{3}
This is done by removing vegetation and top soil not exceeding 300mm deep starting from the existing ground level so as to prepare the site generally for laying the foundation and ground floor slab. However, it does not include detailed excavation of the slab and beams. The bulk excavation is done 1m beyond the house walls to create adequate working space. It is assumed that the depth of bulk excavation is 300mm. The bulk excavation is measured from the structural details.
The bulk excavation volume is determined by multiplying the length, width and depth of the ground area to be excavated.
Some excavated material will be needed to be used as fill because of the ground is uneven as shown by the contours in the building site plan. About half of the excavated material will be used as fill to level the ground for the slab construction. Therefore the amount of fill material needed is about 37m^{3}.
The concrete for each of the elements on the ground is determined by multiplying the length with the width and depth of that particular element as follows
Ground floor slab
6.3m x 5.17m x 0.1m = 3.26m^{3}
5.18m x 5.17m x 0.1m = 2.68m^{3}
6.3m x 5.16m x 0.1m = 3.25m^{3}
5.18m x 5.16m x 0.1m = 2.67m^{3}
3.63m x 4.61m x 0.1m = 1.67m^{3}
Beams
Edge beams (EB):
2 x 12.83m x 0.45m x 0.42m = 4.85m^{3}
1 x 10.97m x 0.45m x 0.42m = 2.07m^{3}
1 x 10.82m x 0.45m x 0.42m = 2.04m^{3}
2 x 3.63m x 0.45m x 0.42m = 1.37m^{3}
Internal beams (IB):
1 x 11.48m x 0.35m x 0.35m = 1.41m^{3}
1 x 10.97m x 0.45m x 0.35m = 1.73m^{3}
1 x 4.61m x 0.45m x 0.35m = 0.73m^{3}
Patio slab
5.17m x 0.35m x 0.1m = 0.18095m^{3}
[(1.32m x 6.35m) – (0.35m x 0.24m)] x 0.1m = 0.8298m^{3}
Pad footings
2 x 0.9m x 1.2m 0.45m = 0.972m^{3}
The net measure of SL72 reinforcing mesh is determined by calculating the net area of ground floor slab and patio slab as follows
Ground slab:
11.93m x 10.97m = 130.87m^{2}
3.63m x 4.61m = 16.73m^{2}
Patio slab:
5.17m x 0.35m = 1.81m^{2}
[(1.32m x 6.35m) – (0.35m x 0.24m)] = 8.3m^{2}
Bulk excavation
Net ground area = 130.87m^{2} + 16.73m^{2} + 1.81m^{2} + 8.3m^{2} = 157.71m^{2}
The number of sheets needed to complete the ground slabs is determined by dividing the net ground area by the effective cover of one sheet. The effective cover of reinforcing mesh sheet is 5.8m x 2.2m with 400mm lap. Thus the number of sheets is calculated as follows
The length of trench mesh needed is determined by calculating the total length of trenches needed for the ground slab. The trench lengths are determined as follows:
3 x 12.83m = 38.49m
3 x 10.97m = 32.91m
2 x 4.08m = 8.16m
1 x 4.61m = 4.16m
Total = 38.49m + 32.91m + 8.16m + 4.16m = 83.72m
The structural steel bars used are of diameter 12 mm and spaced at 200mm apart. The weight of this bars is 0.89kg or 0.00089 tonnes per meter.
(Civilology, 2019)
Length of main bars = no. of main bars x length of one main bar (Hamakareen, 2018); (Krishna, 2019).
Length of main bars = (32 x 5.11m) + (32 x 4.97m) = 163.52m + 159.04m = 322.56m
Length of main bars = (27 x 5.11m) + (27 x 4.97m) = 137.97m + 134.19m = 272.16m
Length of main bars = (19 x 4.51m) = 85.69m
Length of main bars = (8 x 5.45m) = 43.6m
Total length of main bars = 322.56m + 272.16m + 85.69m + 43.6 = 724.01m
Length of distribution bars = no. of distribution bars x length of one distribution bar
Length of distribution bars = (29 x 6.2m) + (29 x 5.08m) = 179.8m + 147.32m = 327.12m
Length of distribution bars = (26 x 6.2m) + (26 x 5.08m) = 161.2m + 132.08m = 293.28m
Length of distribution bars = (24 x 3.63m) = 87.12m
Length of distribution bars = (29 x 1.32m) = 38.28m
Total length of distribution bars = 327.12m + 293.28m + 87.12m + 38.28m= 745.8m
Net measure
The net measure includes the area of walls of the first floor rooms excluding wet areas. The height of the first floor rooms is 2450mm.
Rumpus: 4.5m + 5.52m + 1.99m + 3.36m + 1.71m = 17.07m x 2.45m = 41.82m^{2}
Gallery: 6.06m + 4.16m = 10.22m x 2.45m = 25.04m^{2}
Bed 1: 10.54m + 8.12m = 18.66m x 2.45m = 45.72m^{2}
Bed 2: 7.08m + 6.98m = 14.06m x 2.45m = 34.45m^{2}
Bed 3: 3.54m + 3.23m + 2.14m + 2.22m + 2.15m = 13.28m x 2.45m = 32.54m^{2}
Bed 4: 2.66m + 3.34m + 3.03m + 3.34m = 12.37m x 2.45m = 30.31m^{2}
Net area of walls = 41.82m^{2} + 25.04m^{2} + 45.72m^{2} + 34.45m^{2} + 32.54m^{2} + 30.31m^{2} = 209.88m^{2}
Number of plasterboard sheets
Standard size of plasterboards is 2400mm long and 1200mm wide. Area of one sheet is:
2.4m x 1.2m = 2.88m^{2}
The length of skirting needed for the first floor rooms is as follows:
Rumpus: 4.5m + 5.52m + 1.99m + 3.36m + 1.71m = 17.07m
Gallery: 6.06m + 4.16m = 10.22m
Bed 1: 10.54m + 8.12m = 18.66m
Bed 2: 7.08m + 6.98m = 14.06m
Bed 3: 3.54m + 3.23m + 2.14m + 2.22m + 2.15m = 13.28m
Bed 4: 2.66m + 3.34m + 3.03m + 3.34m = 12.37m
Ensuite: 6.8m + 8.12m + 3.62m + 4.98m = 23.52m
Bath: 6.06m + 6.52m = 12.58m
Hall: 4.16m + 2.22m + 4.3m + 3.04m + 1.59m = 15.31m
Balcony: 11.04m + 3.04m = 14.08m
Total = 17.07+10.22+18.66+14.06+13.28+12.37+23.52+12.58+15.31+14.08 = 151.15m
The length of one skirting is 2.7m
First is to calculate the floor area of the individual gro9und floor rooms
Family room: 4.08m x 5.03m = 20.52m^{2}
Meals room: 2.17m x 4.589m = 9.96m^{2}
Kitchen: 4.589m x 5.87m = 26.94m^{2}
Foyer/stairs: 5.5m x 1.71m = 9.41m^{2}
Net floor area = 20.52+9.96+26.94+9.41 = 66.83m^{2}
Allow 10% wastage =
Size of tiles used is 20cm by 20cm
Area of one tile = 0.2m x 0.2m = 0.04m^{2}
No of tiles =
Table 1: Material quantities take-off
Item |
Particulars |
Unit |
Qnty |
Rate |
Cost |
1 |
Bored excavation for 300mm diameter piers |
m^{3} |
10 |
||
53/π/0.15/0.15/2.5 9.37 |
|||||
2 |
Bulk excavation (excluding detailed excavation for slab and beams) |
m^{3} |
74 |
||
14.83/13.87/0.3 61.71 |
|||||
5.08/7.51/0.3 11.45 |
|||||
73.16 |
|||||
3 |
N25 concrete to the ground slab, beams, patio slab and pad footing |
m^{3} |
30 |
||
3.1 |
Ground floor slab |
||||
6.3/5.17/0.1 3.26 |
|||||
5.18/5.17/0.1 2.68 |
|||||
6.3/5.16/0.1 3.25 |
|||||
5.18/5.16/0.1 2.67 |
|||||
3.63/4.61/0.1 1.67 13.53 |
|||||
3.2 |
Edge beams |
||||
2/12.83/0.45/0.42 4.85 |
|||||
1/10.97/0.45/0.42 2.07 |
|||||
1/10.82/0.45/0.42 2.04 |
|||||
2/3.63/0.45/0.42 1.37 10.33 |
|||||
3.3 |
Internal beams |
||||
1/11.48/0.35/0.35 1.41 |
|||||
1/10.97/0.45/0.35 1.73 |
|||||
1/4.61/0.45/0.35 0.73 3.87 |
|||||
3.4 |
Patio slab |
||||
5.17/0.35/0.1 0.18 |
|||||
1.32/6.35/0.1 0.84 |
|||||
0.35/0.24/0.1 (0.0084) 1.01 |
|||||
3.5 |
Pad footings |
||||
2/0.9/1.2/0.45 0.97 0.97 |
|||||
29.71 |
|||||
4 |
SL72 reinforcing mesh to ground slabs |
^{ } |
|||
4.1 |
Net measure of ground slabs |
m^{2} |
158 |
||
11.93/10.97 130.87 |
|||||
3.63/4.61 16.73 |
|||||
5.17/0.35 1.81 |
|||||
1.32/6.35 8.38 |
|||||
0.35/0.24 (0.084) |
|||||
157.71 |
|||||
4.2 |
Number of reinforcement sheets |
No |
13 |
||
157.71/(5.8/2.2)^{-1} 12.36 |
|||||
5 |
SL12TM |
m |
84 |
||
3/12.83 38.49 |
|||||
3/10.97 32.91 |
|||||
2/4.08 8.16 |
|||||
1/4.61 4.16 |
|||||
83.72 |
|||||
6 |
Structural steel of ground floor |
t |
1.31 |
||
6.1 |
Main bars |
t |
0.65 |
||
32/10.08/0.00089 0.29 |
|||||
27/10.08/0.00089 0.24 |
|||||
19/4.51/0.00089 0.08 |
|||||
8/5.45/0.00089 0.04 |
|||||
0.65 |
|||||
6.2 |
Distribution bars |
||||
29/11.28/0.00089 0.29 |
t |
0.66 |
|||
26/11.28/0.00089 0.26 |
|||||
24/3.63/0.00089 0.08 |
|||||
29/1.32/0.00089 0.03 |
|||||
0.66 |
|||||
1.31 |
|||||
7 |
Plasterboard |
||||
7.1 |
Net measure |
m^{2} |
210 |
||
17.07/2.45 41.82 |
|||||
10.22/2.45 25.04 |
|||||
18.66/2.45 45.72 |
|||||
14.06/2.45 34.45 |
|||||
12.28/2.45 32.54 |
|||||
12.37/2.45 30.31 |
|||||
209.88 |
|||||
7.2 |
Number of plasterboard sheets |
no |
73 |
||
209.88/(2.88)^{-1} 72.88 |
|||||
8 |
66x18mm finished DAR primed pine skirting |
||||
8.1 |
Net measure |
m |
152 |
||
Bed 1 18.66 |
|||||
Bed 2 14.06 |
|||||
Bed 3 13.28 |
|||||
Bed 4 12.37 |
|||||
Ensuite 23.52 |
|||||
Bath 12.58 |
|||||
Rumpus 17.07 |
|||||
Gallery 10.22 |
|||||
Hall 15.31 |
|||||
Balcony 14.08 |
|||||
151.15 |
|||||
Number of skirting pieces |
no |
56 |
|||
151.15/(2.7)^{-1} 55.98 |
|||||
9 |
Ceramic floor tiles |
||||
9.1 |
Net floor area |
m^{2} |
74 |
||
Family room |
|||||
4.08/5.03 20.52 |
|||||
Meals room |
|||||
2.17/4.589 9.96 |
|||||
Kitchen |
|||||
4.589/5.87 26.94 |
|||||
Foyer/stair |
|||||
5.5/1.71 9.41 |
|||||
66.83/1.1 73.51 |
|||||
9.2 |
Number of tiles |
no |
1838 |
||
73.51/(0.04)^{-1} 1837.75 |
Civilology. (2019). How to Calculate Steel Quantity for Slab? – Reinforcement Calculation . Retrieved from Civilology: https://www.civilology.com/bar-bending-schedule-for-slab/
Hamakareen, M. (2018). How to calculate steel quantity for slab, footing and column? Retrieved from The Constructor: https://theconstructor.org/practical-guide/calculate-steel-quantity-slab-footing-column/25533/
Krishna. (2019, January 12). Bar Bending Schedule [BBS] Estimate of Steel in Building Construction. Retrieved from Civil Read: https://civilread.com/bar-bending-schedule-bbs/