Damp problems in a house can be a real nuisance. Whether it's rain seeping through the walls or roof, moisture absorbed from the ground, condensation settling on cold surfaces, or a combination of these factors, it's important to determine the cause of the dampness before attempting to cure it. In this article, we will explore some common causes of damp walls and provide effective remedies that anyone can try.
1. Damp Down Low - Rising Damp
If you notice damp patches, bubbling paint, crumbling plaster, or powdery deposits on wall surfaces close to the floor, rising damp could be the culprit. Rising damp is typically found in masonry walls due to the absence or failure of a damp-proof course, although poor sub-floor ventilation and bad site drainage can also contribute to the issue.
What's the Remedy?
- Improve the drainage of the site by ensuring the surrounding ground slopes away from the building.
- Check that there's enough room under the floorboards for moisture to evaporate from the soil below and pass out through sub-floor wall vents.
- Install a damp-proof course. It's best to consult professionals for this job.
2. Condensation on Walls
If you're unsure about the cause of a damp patch on a wall, you can perform a simple foil test. Dry the wall surface with a fan heater, then tightly tape some kitchen foil over the affected area. If the surface of the foil is wet after 24 hours, you are dealing with condensation. Condensation occurs when moisture-laden air builds up inside the house, and it is often caused by poor ventilation and over-efficient draught-proofing.
What's the Remedy?
- Install extractor fans or vents in kitchens, laundries, and bathrooms to expel moist air outside the house before it causes problems inside.
- Avoid using moisture-producing portable gas heaters to warm cold, damp rooms.
3. Damp Patches
Damp patches on walls are typically the result of penetrating damp, where water from outside enters the brickwork through gaps and cracks. If the patches are clustered around windows and doors, it's likely that rain is getting in through gaps around the frames. If the dampness is below the opening, it may be due to the absence of a drip groove below a projecting sill. Other patches of dampness are most likely caused by faults in the brickwork, such as cracked pointing.
What's the Remedy?
- Keep the external walls, including the pointing and paintwork, in good condition.
- Seal the gaps around window and door frames.
- Clear out or create drip grooves below windowsills.
4. Leaks
Faults in the roof structure, damaged or missing tiles, poor flashing, broken or cracked gutters, and drainpipes can all contribute to dampness in the house. These issues are usually easy to spot, as they are located around the ceiling or on sections of the wall that line up with external pipework. Damp patches may also be the result of leaks in plumbing work embedded in the wall or poorly sealed bathrooms.
What's the Remedy?
- Repair a faulty roof.
- Deal with leaky pipes.
By addressing the specific causes of dampness in your walls, you can effectively eliminate the problem and create a healthier living environment. Remember, it's important to diagnose the cause accurately before attempting any remedies. If you're unsure or the issue is complex, it's best to consult professionals who can provide expert advice and assistance.
Image source: May Chanikran/Shutterstock
