Brick ballast is made of first class well burnt or slightly over-burnt brick-bats to 40 mm gauge for foundations and floor concrete and 25 mm gauge for roof concrete. No under-burnt or “jhama” bricks (over-burnt porous) should be used. About 390 to 420 9-inch bricks and 420 to 440 Indian Standard Modular (IS) bricks make one cu. m of brick ballast. 280 to 351 9-inch bricks and 300 to 370 IS bricks made one cu. m of brick-bats. About 125 cu. m of brick-bats make 100 Cu. m of brick ballast.