You might think that your property has a problem with damp but this is not always the case. The fact is there are many causes of damp; however, rising damp has probably been the most controversial over the years, with some critics suggesting it does not exist. Unfortunately, our team at Britannia Preservation has dealt with many cases of pervasive damp which cannot be attributed to anything other than rising damp! However, rising damp is not the cause of dampness in every case. We have seen some cases where walls that look damp actually have no dampness present.
Our experienced and highly qualified surveyors use a variety of methods to diagnose damp problems:
• Electrical Moisture Meter
• Calcium Carbide Meter
• Salts Analysis
The profile of readings together with visible evidence will allow accurate diagnosis. Gravimetric and salts analysis are the most accurate methods for diagnosing dampness.
Many issues with damp arise from ground water, which is contaminated with salts, such as chlorides and nitrates and other minerals. In the case of rising damp these chlorides and nitrates are drawn into the wall and elements are left behind as evaporation takes place. Over time, the salts can build to a high concentration, particularly in plaster. Chlorides and nitrates are hygroscopic – they absorb moisture from the air. This process causes the plaster to exhibit dampness and the remaining salts can be quickly and easily assessed in our laboratory.
Chlorides and nitrates are not normally in building materials and their presence is strong evidence that rising damp is present. Proving this to be the case is very simple to do, and Britannia Preservation's surveyors can carry out qualitative salts analysis using various methods. One common technique involves removing a sample of wall covering or plaster from the wall and mixing with distilled water to form a solution. Chemicals, in the form of pills, are added to this solution and cause it to change colour if chlorides or nitrates are present.
© Britannia Preservation 2011