November is typically the month when we start seeing the first serious signs of damp and mould in UK homes. As the temperature outside drops, our natural instinct is to close every window and crank up the heating. However, this traps moisture inside the home (generated from cooking, showering, and even breathing).
When this warm, moist air hits a cold surface—like a window pane or an uninsulated external wall—it cools rapidly and turns into water (condensation). If left untreated for even a few days, this sits on the surface and leads to the growth of black mould, which is a serious respiratory health risk, particularly for children and the elderly.
The “Ventilation vs Heating” Dilemma Many people worry that opening a window will waste expensive heat. While you shouldn’t leave windows open all day, “burping” the room is essential.
- The Trick: Open windows wide for just 10 minutes in the morning. This rapidly exchanges the stale, damp air for fresh, dry air from outside.
- The Science: Dry air is actually much quicker and cheaper to heat up than damp air. By venting the moisture, your boiler doesn’t have to work as hard to warm the room back up.
Is your home fighting against you? If you are ventilating and heating correctly but still suffer from cold walls and black mould, the issue might be your insulation. Uninsulated cavity walls act as “cold magnets” for condensation. Under the ECO4 scheme, tenants and homeowners can often get free cavity wall insulation and humidity-controlled extractor fans installed to solve this problem permanently.
