Damp-Proofing & Wall Treatments

Damp walls are one of the most common problems we are called to, and one of the most commonly misdiagnosed. The paint is peeling, the plaster is soft, there is a musty smell, and the wall never seems to dry out — but the cause can be rising damp from the ground, penetrating damp from the outside, condensation from the inside, or a plumbing leak hidden in the wall. Each of these requires a completely different treatment, and applying the wrong one will not only fail, it will make the problem worse.

We start with a proper diagnosis. We look at the pattern of the damp — where it starts, how high it rises, and whether it is worse after rain or worse in the morning. We check the damp-proof course at the base of the wall, the condition of the external render and the gutters, and the ventilation inside the room. We also measure the moisture content of the wall at different heights, because the profile of the moisture tells us whether it is rising from the ground or coming through the wall from outside.

If the damp is rising, we treat it with a chemical damp-proof course injected into the base of the wall, combined with a re-plastering system that includes a salt barrier to stop the salts in the wall from being drawn up into the new plaster. If the damp is penetrating, we treat the outside of the wall with a water-repellent coating or a breathable render, and we fix the gutters and downpipes that are saturating the wall. If the damp is condensation, we improve the ventilation and the insulation, because no amount of waterproofing will stop condensation that is being generated inside the room.

We also deal with the damage the damp has already caused. The salts that are left behind when damp evaporates are hygroscopic — they absorb moisture from the air — so even after the source of the damp is fixed, the salts will keep the wall damp unless they are removed. We strip the affected plaster, treat the wall, and re-plaster with a system that is designed to resist the salts.

The result is a wall that is dry, a finish that stays on, and a room that is healthy to live in. We give you a written diagnosis of what was wrong, what we did, and why — so you know the problem has been fixed at the source, not just covered up.