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.