Let us consider RR ( stone ) masonry wall for the calculation purpose as shown in the below drawing.
Given data:
Length of the stone masonry wall = 15 ft.
Height of the stone masonry wall = 7 ft.
The thickness of the RR masonry wall = 1.5 ft.
The total volume of the RR masonry wall
= [length × height × thickness]
= [15 ft. × 7 ft. × 1.5 ft.]
= 157.5 cu ft.
Before proceeding further, go through the article 👇
👀 . What is random rubble masonry? - Thumb rules in RR masonry calculations.
to understand the calculation procedure without any questions.
A. Material calculation:
1. Volume of rubble stone:
The required vol. of stone
= [1.25 × the vol. of RR masonry wall]
= [1.25 × 157.5 cu ft.]
= 196.875 cu ft.
2. Cement mortar:
The required dry vol. of cement mortar
= 40% of the vol. of RR masonry.
= [40 × 157.5 cu ft. ÷ 100]
= 63 cu ft.
Let us build this wall in the cement mortar of 1:6 ratio
a. The volume of the sand
= [{its ratio ÷ ( total ratio)} × dry mortar vol.]
= [{6 ÷ ( 6 + 1)} × 63]
= [0.8571 × 63]
= 54 cu ft. or
= 1.53 cum.
b. Volume of the cement
= [total dry mortar vol. - volume of sand]
= [63 cu ft. - 54 cu ft.]
= 9 cu ft.
As you know, one bag of cement = 1.226 cu ft.
Number of cement bags
= [9 cu ft. ÷ 1.226 cu ft.]
= 7.34 bags.
B. Labor calculation:
The labor rate per cu ft. of the RR masonry work ranges from INR 10/- to 16/- depending upon the region.
Let us consider an average rate of INR 13/- per cu ft.
The total cost of labor for RR masonry
= total vol. of RR masonry in cu ft. × labor rate/ cu ft.
= 157.5 cu ft. × 13/-
= INR 2,047.5/-
Now, let us calculate the total cost of RR masonry in table format.
Sl. no. Item. Qty. Rate. in INR. Unit. Cost in INR. 1. Rubble stone 196.88 35/- Cu ft. 6,890.80 2. Cement 7.34 380/- bag 2,789.20 3. Sand 54.00 60/- Cu ft. 3,240.00 4. Curing Lump-sum 200.00 5. Miscellaneous Lump-sum 275.00 6.
The material cost = 13,395.00 7.
Add 5% wastage = 669.75 8.
Total material cost = 14,064.75 9.
Labour cost = 2047.50 10. The total cost of RR masonry wall = 16,112.25
Note: To get accurate results, insert your regional market rate of materials & labor, in the above table.
a. The cost of random rubble masonry/cu ft.
= [total RR masonry cost ÷ total masonry vol. in cu ft.]
= [16,112.25 ÷ 157.5]
= INR 102.30 /cu ft.
b. The cost of random rubble masonry/cum.
= [102.3 × 35.3147]
= INR 3,612.70 / cum.
( As 1cum = 35.3147 cu ft.)
Note:
If the work is handed over to any contractor, you have to add 10% extra for his profit.
Thank you for going through this article❤. Have a good day😄.
If you have any quarries, you can ask me in the comment box👇.
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