CALCULATING QUANTITIES OF MATERIALS IN BRICK AND BLOCK WALLING
When calculating the quantity of bricks or blocks in a wall, a mathematical constant is used in each case. For calculating bricks, this is 60 bricks in every square metre of half-brick thick walling. (For one-brick walling, therefore, the calculation is 120 in every square metre.) For calculating blocks, the constant is 10 in every square metre (on the basis that a block is six times the face area of a brick). Over and above these figures, it is necessary to add a percentage for cutting and wastage – a maximum allowance of 10 per cent is usually sufficient.