Is it damp or condensation?
"Damp" just means excess moisture that shouldn't be there. If any part of your home isn't dry to the touch, has mould, or smells musty, it's worth investigating (RICS). Condensation, penetrating damp and "rising damp" are different ways moisture moves through or onto a building – not causes in themselves (RICS).
| Type | What it is | Typical signs and causes |
|---|---|---|
| Condensation | Water vapour turning to liquid on cold surfaces. The most common cause of damp in homes (GOV.UK). | Water on windows; mould around windows, on outside walls and on ceilings near outside walls. Made worse by drying clothes indoors, poor ventilation, unvented tumble dryers, under-heating and overcrowding (RICS). |
| Penetrating damp | Water getting through a wall, roof or floor from outside or from leaks (RICS). | Broken tiles, failed sealant round windows, blocked or leaking gutters, poor pointing, cracked render, internal plumbing leaks (RICS). |
| "Rising damp" | Moisture drawn up from the ground into walls. Usually found in older properties and often misdiagnosed (GOV.UK; RICS). | Raised ground levels, bridged damp-proof courses, rubble under suspended floors. Government guidance says chemical testing is the most appropriate way to confirm it (GOV.UK). |
| Traumatic damp | Water from leaks or flooding (GOV.UK). | Burst pipes, leaking showers and baths, flooding. |
Reducing condensation
- Use extractor fans whenever you cook, bath or shower, and keep kitchen and bathroom doors shut (RICS).
- Ventilate: about 5 minutes per hour in a room you're using is enough, or use trickle vents (RICS).
- Keep the home heated, ideally between 18°C and 21°C (RICS).
- Cover pans, vent tumble dryers outside, and wipe condensation off windows daily (RICS).
Condensation is not a "lifestyle" failing. Government guidance says it's totally unreasonable for landlords to blame damp and mould on tenants' lifestyle choices, because everyday activities like cooking and drying clothes are unavoidable (GOV.UK).
When to get a survey
If mould keeps coming back, damp patches don't match the condensation pattern, or someone has quoted you for damp-proofing, an independent survey will find the source. Cracked or failed render is a common source of penetrating damp – if that's the culprit, see our sister site London Render Removal.