Damp on Walls: What Causes It and How to Stop It

Damp on walls is a problem that no homeowner wants to have to deal with. Besides being unpleasant to look at, it poses a health risk by encouraging mould growth, and it’s often a sign that there’s more extensive damage happening behind the scenes. If you’ve noticed damp on your walls and are wondering why it’s there and what you can do about it, you can find the answers below.

When Should I Worry About Damp on Walls?

Damp may appear in small patches which seem harmless at first, and reliable advice, such as that from an independent damp surveyor, comes at a price. You don’t want to spend money to hear that there’s nothing to worry about. So, when should you contact a professional? Generally, damp patches that are persistent or spreading are the ones to worry about most, especially if they return after you’ve cleaned or repainted the area.
Small, contained patches that only show up after heavy rain tend to be less of a problem. However, it’s not black and white. All damp is worth treating, as minor issues can quickly escalate.

Does Heating Help With Damp?

Damp patches on walls often feel wet and cold to touch, so it’s natural to assume that heating them will help. However, if things were so simple, there would be no need for independent damp surveys. Heating can help if the damp is caused by condensation, because condensation happens when humid air comes into contact with a cool surface. If the surface is warm, the moisture stays in the air.
However, this approach must be combined with good ventilation. If the humid air can’t escape, then your condensation problem will return as soon as the temperature drops. And if the damp is caused by something other than condensation, then heating will have little effect at all.

What Causes Dampness on Walls?

Damp on walls has three main causes: condensation, water ingress through external walls or the roof, and water ingress from the ground. The second of these is known as penetrating damp, and happens when rain gets in through cracks, porous brickwork, and other defects. The third is known as rising damp, and it happens when a protective layer near the base of a building is missing or defective.
Identifying the correct cause of damp is crucial to treating it effectively. However, the different types of damp are not always easy to tell apart without training and experience. Professional damp specialists, such as independent damp surveyors, use a variety of different tools to make an accurate diagnosis.

How Do You Treat Damp on Walls?

The right way to treat any damp problem is to tackle the root cause first. Condensation is usually resolved by improving ventilation, so that moisture-rich air is quickly removed from the property. Penetrating damp is treated by finding and fixing external defects, and rising damp is stopped by injecting protective chemicals near the base of a building’s walls.

Conclusion

Do you have damp on your walls and you’re not sure why? Book an independent damp survey in London today by calling London Damp Specialists on 020 7205 4886.