Guides & Information

» Damp Proofing

[Top»] Condensation

There are different causes of damp which require different treatments.  The most common dampness in homes is caused by condensation occurring in areas such as kitchen and bathrooms.  It is now a legal requirement for new build properties to have extractor fans fitted to manage the humidity in these rooms.  If your property is older and does not have an extractor fan and you’re noticing high levels of condensation it could be a worthwhile investment to install one as they can prevent more serious problems occurring.

[Top»] Rising Damp

Rising Damp may not initially be as easy to identify but left untreated can cause serious problems for the home owner. Rising damp in buildings can be defined as the vertical flow of water up through a permeable wall structure, the water being derived from ground water. The water rises through the pores (capillaries) in the masonry by a process loosely termed ‘capillarity’. In other words the masonry acts like a wick.

[Top»] Damp Proofing

Ground water contains small amounts of soluble salts, the most significant of which are chlorides, nitrates and sulphates. These pass with the water up the wall and are left behind when the water evaporates. Over many years of active rising dampness large quantities of these salts accumulate within the masonry and decorative surface, most becoming concentrated in a general ‘salt band’ towards the maximum height of rise.  Frequently, the concentrations of these salts are very low towards the base of the wall.

Both chlorides and nitrates are usually hygroscopic, i.e., they can absorb moisture from the surrounding environment and, in general, the greater the amount of salts the greater the absorption of moisture especially under humid conditions. Thus, even though rising dampness may have been controlled by the insertion of a remedial damp-proof course these salts alone can cause the wall and any contaminated decorations to remain damp.

It is important that treatment of rising damp, know as Damp-proofing or Damp coursing to provide a ‘dry’ wall and a suitable surface to take new decorations involves two processes, firstly the insertion of the chemical damp-proof course and secondly the removal of old contaminated plaster-work and decorations, and replacing with specialist re-plastering to prevent the passage of any residual moisture and contaminant salts to the new surfaces from the underlying masonry.

[Top»] Who are the experts?

The experts -

The British Wood Preserving and Damp-proofing Association, founded in 1929, has now established separate associations for its members working in the property care sector (dry rot, wet rot and woodworm treatment, wall-tie replacement, damp-proofing and water proofing) and the wood protection sector (treatment of new timber to protect against the risk of insect or fungal attack or fire in service, protective coatings to protect against weathering or fire and DIY wood protection).

These are the largest associations of their kind in Europe, and are the nationally recognised authorities on timber and damp problems. They set high standards for their members in technical competence, health, safety and environmental protection and customer service. Members provide answers to a wide range of problems.