Condensation and Mould

There is always some moisture in the air and warm air holds much more moisture than cold air. As soon as warm air hits a cold surface it cools down and is forced to release some of the moisture, making the cold surface wet. This "wetness" is condensation. We see condensation most commonly as steam or mist that appears on bedroom windows in the morning or on the bathroom mirror. The 'breath' that you can see when you go out on a cold day is condensation.

How does condensation damage our homes and affect our health?

Condensation occurs mainly in cold weather and is found on the coldest surfaces or in places where there is little or no movement of air, such as the corners of rooms, near windows or behind furniture. It mostly appears on north facing walls which are colder because they don't get the sun.

Damp caused by condensation can cause mould and mildew to grow on walls, fabric and furniture which eventually leads to rotting. It can also cause paint to blister and wallpaper to peel off. Mould gives off tiny seeds called 'spores', which float in the air (this is how it spreads) and can make conditions such as asthma worse.

Why is it worse these days?

Improvements in homes such as draught proofing on doors and sealed window units have made it easier to keep our homes warm by minimising draughts and stopping heat escaping. But these improvements can also stop moisture escaping, which is why condensation problems have increased.

Images provided by National Energy Action (external)

How do you rate this information/service?