Damp Proofing

Damp proofing is a protective process to ensure moisture cannot pass through the walls of a building to the interior. Damp proofing places a barrier in walls which prevents rising damp, with other methods available to prevent penetrating damp problems prevalent in modern homes. These measures can also eliminate the possibility of future damp-related problems such as wet rot, dry rot, and mould.

In general damp proofing is a generic term used to describe a variety of treatments and solutions available to prevent damp problems affecting a property. So how does Approved Plastering identify problems that can require damp proofing?

Rising Damp
Rising damp is an issue that can affect all types of buildings. It is particularly prevalent in older houses where the damp proof course has deteriorated or where the external ground level has been raised above floor level. Rising damp is caused by moisture from the ground rising by capillary action through porous masonry.

Penetrating Damp
Penetrating damp (or moisture ingress spreading through the wall fabric horizontally) is an issue that can affect all types of buildings. Typically penetrating damp is caused by issues with the building, or plumbing, where a problem has allowed water to enter the property. Common problems are defective exterior render or roughcast coatings, defective exposed brickwork, leaking roofs and defective external plumbing (Waste water pipes and gutters).

Condensation is simply the moisture created within the building caused by everyday living. Moisture is absorbed into the warm atmosphere of the building and once the building cools down the moisture present condenses on cold or cooler surfaces. This often results in black mould forming in these areas. This can often be mistaken for rising or penetrating damp due to the mould present.

Treatments and Solutions
Internal finishes (plaster) that have been contaminated by damp or hygroscopic salts must be removed back to the substrate prior to any remedial work commencing. For rising damp treatment a new chemical damp proof course is installed by either low pressure injection or silane diffusion via holes drilled into the masonry structure. Following the suitable application of the damp proofing process required for the project the substrate should be reinstated using a Ventilated Damp Proof Membrane or the application of Specialist Renovating Plasters.