The perforated bricks are used in the construction of brick panels for lightweight structures and multi-storeyed framed structures. The perforations may be circular, square, rectangular or any other regular shape in cross-section. The distance between the side of brick and edge of perforation should not be less than 15 mm. The distance between the edges of successive perforations should preferably be not less than 10 mm. The water absorption after immersion for 24 hours in water should not exceed 15 percent by weight. The compressive strength of perforated bricks should not be less than 7 N/mm2 in gross area.
Acid brick – acid resistant bricks.