In order to calculate the quantities of cement and sand required for 10 cm thick brick partition wall, with I.S. size (i.e. modular) bricks, the procedure would be as follows.
Considering 10 sq.m area of the brick work to be constructed with 10 cm thick wall.
The quantity of brick work in partition = 10 x (10/100) = 1 cum.
Therefore, Number of bricks required (considering the thickness of joints on 10 cm)
= 100/(0.20 x 0.1 x 0.1)
=500
Adding 5% extra for wastage = 25
Therefore, Total number of bricks = 525
Therefore, Quantity of mortar required = (10 x 0.1) – 500(0.19 x 0.9 x 0.9) = 1 – 0.77 = 0.23
Adding 10% extra for frog, bonding, wastage, etc. = 0.023
Therefore, Wet volume of mortar required = 0.253 cum.
Therefore, Dry volume required = 1.25 x 0.253 = 0.316 cum. = 0.30 cum.
i.e. for 10 sq.m area of brick work thickness 10 cm, the quantity of dry mortar required = 0.3 cum.
Further, knowing the proportion of mix, the quantities of cement and sand can be found out by dividing the total quantity of dry volume of mortar by the sum of the numerical figures of the proportion or mix of the mortar and then multiplying it by the individual numerals.
Basics for Site Engineer 