Types of Damp in Cardiff Homes
Cardiff's Victorian and Edwardian housing stock — particularly in Roath, Canton, Splott, Grangetown, and Pontcanna — is especially prone to damp due to its age and construction methods. The main types:
Rising damp: Moisture drawn up through masonry from the ground. Appears as a tide mark on lower walls, often with white salt deposits (efflorescence). True rising damp requires a damp proof course (DPC) injection or installation.
Penetrating damp: Water entering through the external fabric — failed pointing, cracked render, blocked gutters, or defective flashings. The most common damp type in Cardiff's older properties. Always fix the cause before treating the symptoms.
Condensation: The most common form of indoor damp in Wales. Moisture in warm air condenses on cold surfaces — typically around windows, in corners, and in poorly ventilated rooms. Needs improved ventilation and heating, not chemical treatments.
Important: Many damp problems in Cardiff are misdiagnosed as rising damp when they're actually condensation or penetrating damp. An independent surveyor (not a damp-proofing company) will give an unbiased diagnosis.
Damp Proofing Costs in Cardiff
| Treatment type | Typical Cardiff cost |
|---|---|
| Chemical DPC injection (per linear metre) | £30–£70 |
| DPC injection for semi-detached (2 floors) | £800–£2,500 |
| Tanking (basement/cellar) | £50–£150 per sq m |
| Re-rendering (external, per sq m) | £25–£55 |
| Repointing (per sq m) | £30–£65 |
Always get a damp survey from an independent RICS surveyor before commissioning treatment — damp proofing companies have a commercial interest in diagnosing problems that require their services.