Specialist Re Plastering
As moisture rises from the ground into a wall it carries with it soluble ground salts, which are deposited in the wall fabric and wall plaster as the moisture evaporates. Certain of the soluble salts carried up from the ground by rising damp and in particular chlorides and nitrates are hygroscopic, that is they will attract moisture from the atmosphere. Where dampness continues to rise into a wall for a substantial period the deposit of hygroscopic salts built up may be sufficient to cause a significant dampness problem, particularly at periods when the relative humidity of the atmosphere is high. Note: Hygroscopic Salts should not be confused with the deposits of efflorescent salts which may appear on a wall surface as the wall dries out. Efflorescence on wall surfaces is usually caused by sulphate salts which are soluble but not hygroscopic.
Rectification of Dampness caused by Salt Contamination
Wall plaster affected by hygroscopic salts must be removed, and the wall re-plastered using a specialist plastering system that does not readily allow any salts within the wall fabric, to migrate to the surface of the new plaster. We as members of the Property Care Association issue specific recommendations regarding re-plastering with any Independent Survey report that we submit. It is obviously advisable to follow any such recommendations.
There are various types of plastering systems that can be used including; dry lining systems and Plaster membranes.
We always recommend to the client to engage the services of a PCA contractor member.