Water Proofing Materials
Dampness in a building is the main cause of the deterioration of the building as well as for the ill-health of the occupants. The damp brickwork in the buildings is prone to fresh attack. Also, the soluble salts in bricks are liable to attack the cement mortar when the brickwork remains wet for long period and consequently the wall paints may also flake.
This main cause of dampness is the absorption of water by the materials because of high ground water table, rain, exposed top of parapet wells, inadequate slope of roof, pounding of water in adjoining areas of the structure and condensation.
Damp-Proofing Course (DPC)
The damp-proofing of a building is done by interposing layer of damp-proofing material between source of dampness and building and this layer is known as Damp-Proofing-Course (D.P.C.).
The principle of damp-proofing is to provide D.P.C. horizontally or vertically without any break and throughout the thickness of wall.
A good water proofing material should be impervious, durable and should be able to resist loads to which it will be subjected. It should be in position to accommodate some structural movement without fracture. The materials commonly used to check dampness can be divided into the following four categories-
- Flexible Materials
The examples are bitumen felts, plastic sheeting (Polythene sheet) etc.
- Semi-Rigid Materials
The examples are mastic asphalt or a combination of materials or layers.
- Rigid Materials
The examples are first class bricks, stones, slates, cement concrete etc.
Grout consists of cement slurry and acrylic based chemicals/polymers.
The choice of a material to function as an effective damp-proof course requires a judicious selection. It depends upon the climatic and atmospheric conditions, nature of structure and the situation where D.P.C. is to be provided.
Rigid Pavements: Objective, Advantage, Disadvantage, Components, and Affecting Factors
Flexible Pavements: Objective, Advantage, Disadvantage, Components, and Affecting Factors
Types of Joints in Rigid Pavements: Longitudinal and Transverse