DAMP PROOFING MATERIALS

Prevention of dampness in a building is achieved by using a suitable damp proofing material.

The properties of damp proofing materials are:

1. It should be impervious to moisture.
2. The damp proofing property should remain constant with lapse of time.
3. Damp proofing material should be stable in loaded and unloaded conditions.

11.5.1 Different types of damp proofing materials

1. Cement mortar: Cement mortar in the ratio 1:3, in layers of 2-3 cm with a suitable damp proofing compound, such as cico, impermo, etc.
2. Cement concrete: Cement concrete 1:2:4, 6 to 15 cm thick, with or without 3–5 per cent damp proofing compound.
3. Bitumen: A 3 mm thick layer of bitumen is placed on a bed of concrete or mortar. Bitumen is a by-product of petroleum distillation, which is used for roadwork.
4. Bituminous felt: This material is available in rolls of normal wall thickness.
5. Metal sheets: Copper and aluminium sheets are used as damp proofing material.