Basics in Building Construction

Basics in Building Construction 4(2+2)

Lesson 04 : Damp Proofing : Methods And Materials

Ideal Materials for Damp Proofing

An effective damp proofing material should have the following properties.

• The material should be impervious. It should not allow any moisture penetration through it.
• It should be strong and durable.
• It should be capable of withstanding both dead as well as live loads without damage.
• The material should be flexible, so that it can accommodate the structural movements without any fracture.
• It should be free from deliquescent salts like sulphates, chlorides and nitrates.
• The material should be such that leak-proof jointing is possible.
• The material should remain steady in its position when once applied. It should not allow any movement in itself.

The materials recommended for Damp Proof Course can be divided into three categories

1. Flexible materials like bitumen felts, fiber, glass fibre based, plastic or polythene sheet.
2. Semi-rigid materials like mastic asphalt or combination of materials or layers.
3. Rigid materials like first class bricks, stones, cement concrete etc. The choice of materials to function as an effective damp – proof course requires judicious selection. It depends upon the climatic and atmospheric conditions, nature of structure and the situation where Damp Proof Course is to be provided.