Classification based on types of bricks

• Solid brick

1. Those in which small holes passing through or nearly through the brick do not exceed 25 percent of its volume , or in which frogs do not exceed 20% of its volume
2. A small hole is defined as a hole less than 20mm wide or less than 500mm square in area .

• Perforated bricks

1. THose in which holes passing through the brick exceed 25 percent of its volume and the holes are small as defined above

• Hollow bricks

1. Those in which the holes passing through the brick exceed 25 percent of its volume and the holes are larger than those defined as small holes.