Damp Proofing across Greater London

Damp walls come from three main sources. Penetrating damp is water getting in from outside, through leaking gutters, failed render, worn pointing or a defective roof. Condensation forms when moist indoor air meets cold walls, and shows as mould in corners and behind furniture. Rising damp is ground moisture drawn up through masonry where the damp-proof course has failed or been bridged. Each needs a different fix, and treating the wrong one wastes money without curing the problem. Ashlar Roofing starts by working out which of these is affecting your property.

In practice, many damp problems turn out to be leaks or condensation rather than true rising damp, so injecting a new damp-proof course is not always the answer. Where the evidence does point to rising damp, we can inject a chemical DPC and replaster with a salt-resistant plaster, so salts left in the wall do not spoil the new finish. Walls below ground level can be tanked to hold back moisture from the soil. Just as often, the fix is outside: clearing a gutter, repairing render, repointing brickwork or lowering ground levels that sit above the DPC.