Dampness in buildings is a common problem during the construction of homes, and it has been known to compromise the structural integrity while ruining the aesthetics of a structure. Damp-proofing refers to the treatments or techniques that deter dampness in the environment from penetrating the floors and walls of a building. The installation of a damp-proof course (DPC) prevents the ingress of moisture into a home and thus averts damage to fittings, fixtures and finishes. Here are some key tips about DPCs for new home builders.
Causes of Dampness -- Several factors contribute to dampness in a building. However, these factors can be narrowed into three based on the type of damp: rising damp, condensation and penetrating damp. Rising damp is caused because of capillary action, which forces moisture to rise through porous elements. Condensation refers to the cooling of water vapour as warm air touches cooler surfaces. Condensation in buildings is likely to cause corrosion, mould growth and staining, among other things. Penetrating damp is caused by moisture moving laterally through the building through the exterior surface.
Types of Damp-Proof Courses -- Damp-proof courses in new buildings serve two purposes. First, they prevent rising damp from affecting the floors and walls. Second, DPCs deter penetrating damp from moving laterally. The common types of damp-proof courses include cement mortar, bituminous material, engineering bricks and polyethylene. Also, any other construction material that can act as a barrier to moisture seepage can be used as a damp-proof course.
Where to Install Damp-Proof Courses -- A DPC is usually installed at the concrete slab level of the ground floor to prevent rising damp. Besides, a damp-proof course can be installed around door and window frames, in cement brick walls and in multi-storey buildings. For cavity walls, it is recommended to bridge the windows and walls using a flexible membrane, such as bitumen.
Membrane Damp-Proofing -- A membrane damp-proofing is a water-resistant barrier that is placed between the origin of the dampness and the section of the building close to it. Such a membrane is installed either vertically or horizontally in walls and floors. The common types of materials used in membrane damp-proofing are bituminous material, polythene sheets and cement. Note that when installing a DPC, the material should cover all the surfaces to offer a continuous barrier. If you are using mortar, make sure it is levelled well to prevent damage caused by projections.
To learn more, contact a civil works contractor.