Finding the cause comes first
Damp shows up as stained or peeling paint, crumbling plaster, salts on the wall, a musty smell or black mould in the corners of a room. Those are symptoms, and they can come from very different places: water rising from the ground, water getting in from outside, or moisture produced inside the house with nowhere to go. Treating the wrong one wastes money and leaves the problem in place, so every damp proofing job starts with working out where the moisture is coming from.
We cover all aspects of damp proofing, including waterproof tanking systems, mould removal and ventilation, and damp course injections. Our services are there to remedy damp, mould and timber decay problems within your property, and because plastering is our trade, we can put the walls back to a sound, smooth finish once the cause has been dealt with.
Rising damp and damp course injections
Rising damp is moisture drawn up from the ground into the base of a wall. It usually leaves a tide mark and damaged plaster in the lower part of the wall, often with white salts blooming on the surface. Many older homes were built with a damp proof course that has since failed or been bridged, for example by raised paths, flower beds or render taken down to the ground.
Where a new damp proof course is needed, a damp course injection puts a water-repellent barrier into the mortar course at the base of the wall. The salt-contaminated plaster above it is removed and the wall is re-plastered with a suitable system, because old plaster full of salts will keep pulling moisture from the air even after the wall itself has dried out.
Penetrating damp
Water can also get in sideways, through cracked render, failed pointing, leaking gutters and downpipes, or around windows and doors. Penetrating damp tends to show as patches at any height that get worse after rain, and the fix starts outside, at the point where the water is getting in. Where cracked or failing render is the cause, our rendering service can put it right before the inside of the wall is repaired.
Tanking for cellars and below-ground walls
Walls below ground level, such as cellars, basements and rooms built into a slope, hold back soil and water and can never dry out from the outside. They need a waterproof tanking system on the inside face. Depending on the space, that can be a waterproof render or coating applied directly to the wall, or a studded cavity drainage membrane fixed to the wall, which lets any water behind it drain away while the room in front stays dry. Either way, the finished wall can then be plastered or dry lined to make a usable room.
Condensation and mould
Black mould on cold walls, window reveals and ceilings is very often a condensation problem rather than water getting in. Cooking, washing, drying clothes indoors and simply breathing all put moisture into the air, and without enough ventilation it settles on the coldest surfaces in the house. We carry out mould removal and ventilation work, and where cold walls are part of the problem, insulation and dry lining help keep the wall surface warmer. Our dry lining and insulation page explains more.
Putting the walls back
Damp proofing nearly always leaves walls that need making good. Because plastering is our core trade, we re-plaster or re-render treated walls ourselves, using materials suited to a wall that has been damp, rather than handing the finish on to someone else. The result is a dry wall with a smooth finish, ready to decorate when it has dried out.
Get advice
If you have a damp patch, mould or crumbling plaster in a home or commercial property in Worthing or elsewhere in West Sussex, call 07824 165672. Quotes and advice are free and without obligation.
