The four main types of damp
| Type | What it looks like | Usual cause |
|---|---|---|
| Condensation | Mould in corners, wet windows, worse in winter | Moist air and poor ventilation |
| Penetrating damp | Damp patches that grow after rain, often high up | Gutters, pointing, render, roofs, window seals |
| Rising damp | Tide mark up to about a metre, salts, crumbling plaster | Failed or bridged damp proof course |
| Leaks | Patches near pipes, below bathrooms, ceiling stains | Plumbing, waste pipes, flat above |
Why diagnosis matters
Each type of damp needs a completely different fix. Injecting a damp proof course into a wall that is wet from a leaking gutter wastes your money and the wall stays wet. Most damp in London homes turns out to be condensation, penetrating damp or a leak, and these are often cheaper to fix than people fear. That is why a proper damp survey comes first.
How we work
- Survey. Moisture readings, salt checks, outside inspection of gutters, pointing, render and ground levels.
- Written findings. The cause, the evidence and the options, with photos.
- Fixed quote. One price for the repair, the drying out and the making good.
- Repair and replaster. Using breathable materials suitable for older solid wall homes where needed.
- Mould treatment. Any mould is treated and covered by our 6 month guarantee.
Older London homes
A lot of homes in London are Victorian and Edwardian with solid brick walls. These walls are designed to breathe. Covering them with cement render, gypsum plaster or plastic paints can trap moisture and make damp worse. We take that into account in every repair we quote.
Questions people ask
Is damp treatment covered by home insurance?
Gradual damp usually is not, but sudden damage from an escape of water like a burst pipe often is. Check your policy, and we can provide a report to support a claim.
Can you fix damp in a rented flat?
Yes. We work for landlords and agents and can coordinate with the tenant for access. See our landlords page.