Rising damp is the upward movement of moisture in walls as a result of water beside or underneath the wall travelling by capillary action (the suction of water through small cracks in stone or brick). This causes issues when the moisture penetrates finishes and materials in the interior of the house. Often this moisture will carry salts from the ground. When the dampness evaporates, these salts become concentrated in the plaster and wall. These salts can absorb moisture from the air inside the house leaving the walls visibly wet.
If the damp walls remain untreated it can cause further problems for the building. Moisture levels may rise to point at which timber skirting boards and any timber along the base of the wall become infected with dry rot, wet rot or woodworm which will lead to the decay of these fixtures.
What are the signs of rising damp?
Rising damp is often misdiagnosed. The moisture stops rising at a height where gravity works against the upward force of the capillary action. Therefore, the maximum height rising damp usually reaches is a little over 1m to 1.2m.
If rising damp is present you would see a ‘tide line’ of discoloured staining or bubbling plaster above your skirting board. There may also be signs of dampness and rotting of flooring or skirting board. Damp conditions allow for mould growth which, not only looks bad and damages finishing’s, it is a health hazard.
What We Recommend
Almost all modern properties are buit with a damp-proofing mesh membrane placed below masonry walls to prevent rising damp. Some properties may have been built without this damp-proof course or sometimes the existing one may fail which would result in rising damp. Walls contaminated with salt may need to be replastered.
We advise that you get expert advice before making any decisions on treatments.
Acorn Property Preservation can provide a detailed survey report to specify remedial treatments and works to be carried out by our experienced team of technicians and trades people, or work in conjunction with your local trusted trades people.