Damp is one of the most common problems found in homes, and one of the most misunderstood. Some damp is cosmetic and cheap to cure; some signals a serious, expensive fault. Learning to spot the signs and ask the right questions stops you mistaking a minor issue for a disaster, or the other way around.
The three kinds of damp
Damp comes in three main forms. Condensation, the most common, occurs when moist air meets cold surfaces and is often a ventilation problem. Penetrating damp comes through walls or roofs from outside, usually because of a fault like a cracked gutter. Rising damp, less common than people fear, draws moisture up from the ground through the walls.
What to look for
On a viewing, use your eyes and nose. Watch for tide marks low on walls, peeling paint, blistering plaster, black mould in corners, and a musty smell. Be wary of fresh paint on one patch of wall or furniture pushed against a particular spot, which can hide a problem the seller would rather you missed.
- Staining and tide marks on walls, especially low down
- Mould and a musty smell often pointing to poor ventilation
- Flaking plaster or paint where moisture is at work
Getting to the cause
Damp is a symptom, and the cure depends on the cause. Condensation often clears with better ventilation and heating. Penetrating damp needs the external fault fixed. The mistake is to treat every damp patch as rising damp and pay for an injected course that may not be needed. A good surveyor diagnoses before prescribing.
Using it in negotiation
If a survey flags damp, get a specialist to identify the cause and quote for the cure before you panic or pull out. Armed with a real figure, you can ask the seller to reduce the price or fix the problem. Damp handled knowledgeably is a bargaining chip, not necessarily a deal-breaker.