Black mould in the corner of a bedroom, streaming windows every morning, a musty smell in the wardrobe. It's a common story in older South London houses, and it's nearly always down to the same two things: too much moisture and not enough ventilation.
Where condensation comes from
Cooking, showering, drying washing indoors and even breathing put litres of water into the air every day. When that warm, damp air hits a cold surface, like a single-glazed window or an uninsulated outside wall, it turns back into water. Leave it there and mould follows, along with rotting window frames and mildew on clothes and curtains.
Quick fixes
- Use the extractor fan when cooking and showering, and leave it running for a while after
- Keep trickle vents open
- Avoid drying washing on radiators where you can
- Keep the heating at a steady low level rather than blasting it on and off
Longer-term fixes
If the problem keeps coming back, the house needs work. Insulation keeps internal surfaces warmer, so condensation has nowhere to form. The areas that make the biggest difference are:
- Cavity or solid walls
- The roof and loft
- Hot water tanks, radiators and pipes
- Floors, especially suspended timber floors
- Draught-proofing around doors and windows
Insulation and ventilation have to work together. Seal a house up without proper ventilation and you can make damp worse. That's why we always look at both when we're extending or refurbishing.
If you're planning work and want to sort damp and heat loss at the same time, get in touch for a free site survey.