Rising damp is a common and troublesome problem in UK homes. It’s not just unsightly – causing peeling paint, flaking plaster and unpleasant odours – but it can also lead to serious structural damage and health concerns if left untreated.
If you’ve noticed mysterious damp patches on your ground floor walls or a musty smell lingering in your home, it’s time to investigate.
Here, we’ll walk you through what rising damp is, how to spot it and most importantly, how to tackle it effectively.
What Is Rising Damp?
Rising damp occurs when moisture from the ground is absorbed by a building’s walls. Most UK properties are built with porous bricks and mortar, which unfortunately can act like a sponge when there’s no effective damp-proof course (DPC) in place. This moisture carries salts and minerals from the ground upwards, which can damage plaster, wallpaper, paint, and even timber.
Unlike condensation or penetrating damp, which come from internal sources or external leaks, rising damp tends to start at the base of a wall and move upwards.
It’s most commonly found in older properties where DPCs may be missing, damaged, or have failed over time.
Signs of Rising Damp
Identifying rising damp early is key to preventing costly repairs down the line. Here are the tell-tale signs to look out for:
- Damp or discoloured patches on ground floor walls
- Tide marks or a visible stain line, often up to 1 metre above the floor
- Flaking paint or wallpaper
- Crumbling or salt-stained plaster
- Musty odours in the affected area
- Rotting skirting boards or timber floorboards.
If you’re unsure whether the damp in your home is rising damp or another type, a professional diagnosis is essential.
Causes of Rising Damp
The root cause of rising damp is usually one of the following:
- The absence of a damp-proof course (DPC) in very old properties (pre-1875)
- Failure or breakdown of the existing DPC
- Bridging, which is where ground levels or external paths are higher than the internal DPC
- Blocked cavities or poor drainage around the base of the house.
It’s really important to diagnose the cause correctly, because this will determine the right course of action for treatment.
Treatment Options for Rising Damp
Once confirmed, treating rising damp involves more than just cosmetic fixes – so you can’t just paint over any damp patches and hope the problem goes away.
It’s typically treated through one or more of these steps:
1. Install or Repair a Damp-Proof Course
A chemical DPC can be injected into the wall to create a barrier against moisture. In more severe cases, physical damp-proof membranes may be installed.
2. Address Bridging and Ground Levels
This ensures soil, paving or decking around your home is at least 150mm below the DPC level to prevent moisture bridging.
3. Replastering and Redecoration
Once the source of moisture is stopped, the affected plaster will need to be removed and replaced with a salt-resistant render. Then you can redecorate – but only once the wall is fully dry.
Why Use Professionals?
DIY damp solutions often treat the symptoms rather than the source, and misdiagnosis can lead to wasted time and money.
This is why working with experienced damp specialists is crucial. An expert can accurately assess the problem, recommend the most effective treatments, and ensure work is carried out to a professional standard. Most will also offer guarantees for peace of mind.
Prevention Tips
To keep your home damp-free in future, follow these tips:
- Keep air bricks and vents clear to allow for ventilation
- Maintain gutters and downpipes to prevent water ingress
- Monitor ground levels outside your property
- Regularly inspect your home for early signs of damp.
Rising damp may be a common problem, especially in the UK’s older housing stock, but it doesn’t have to become a costly disaster. With early detection, proper treatment and professional help, you can restore your home’s health and appearance.
If in doubt, always consult with professionals who specialise in damp issues to ensure a long-term fix.
