Category: 6. Damp Proofing

It is used in two ways, either (i) as a bed layer for receiving other types of DPC or (ii) as a waterproofing plaster. For the bedding layer, mortar is prepared by mixing cement and sand in the ratio of 1:3 and adding a little lime to increase the workability. For waterproof plasterwork, mortar is…

It is also a flexible material, available in rolls of normal wall width. To hold it in position, a layer of cement mortar is first laid over the brickwork and then DPC is laid over it. 10 cm overlap in case of joints and full width overlap in case of angles and crossings should be…

It is a flexible material, which is first heated and then spread over a bed of concrete or mortar (ie over the walls). It should not be applied in thickness less than 3 mm. Bitumen or asphalt makes an excellent damp-proof course, as it offers an impermeable, indestructible and hard surface.

There are different materials, which are used as damp proof courses depending on location, economy and degree of damp proofing required. However, when choosing a particular damp proofing material, the following requirements for an ideal damp proofing material should be kept in mind. Materials for DPC must be impervious and durable, meaning the material must…

Cementation is the process or technique of forcing cement grout (ie a mixture of cement, sand and water) under pressure into cracks, voids or fissures in a structural component or ground. That is, all the components of a structure in general and foundations in particular, which are liable to ingress of moisture, are strengthened and…

It is used to form an impermeable layer using rich cement mortar (1 cement: 3 sand or fine aggregate mix) for waterproofing over exposed concrete surface or pipes, cisterns etc. to resist water pressure. contains Gunite is a mixture of cement and sand or well-graded fine aggregate, the usual ratio being 1:3 or 1:4 (ie,…

A cavity wall consists of two parallel walls or leaves or skins of masonry separated by a continuous air space or cavity. The walls of the cavity consist of three main parts, namely, Outer wall or leaf (10 cm thick) which is the outer part of the wall.A cavity or air space of 5-8 cm.Inner…

Integral treatment consists of adding certain admixtures to the concrete or mortar during the mixing process, which act as a barrier to moisture ingress under various principles when used in construction. Admixtures such as chalk, talc and filler earth have a mechanical principle of action, meaning they fill the voids in concrete or mortar, making…

Surface treatment consists of filling the pores of the material exposed to moisture by providing a thin film of water-repellent material on the surface. Surface treatments can be either external or internal. External treatment is effective in preventing dampness while internal treatment reduces it to a certain extent. Many surface treatments such as pointing, plastering,…

These are layers or membranes of water-resistant materials, such as bituminous felts, mastic asphalt, plastic sheets, cement concrete, mortar, metal sheets, slates and stones, which are attached to the building structure at all points where These damp-proof courses of suitable material where water ingress is likely or suspected should be provided at suitable locations for…