Expert help from Damp and Mould Solutions Ltd
Rising damp can feel overwhelming. It’s slow, stubborn, and silent – until the skirting starts peeling or your floorboards begin to warp.
But treating rising damp doesn’t have to be complicated. Whether you live in a stone cottage, a brick Victorian, or a semi-detached 70s build, the approach is similar. This guide breaks it all down – simple steps, practical advice, and real solutions.
🧱 What is Rising Damp?
Rising damp is when moisture from the ground travels up through your walls. It moves by capillary action, which means it climbs through tiny pores in bricks, stone, or mortar – just like how a sponge pulls in water.
Most homes have something called a damp proof course (DPC) to stop this from happening. But if the DPC fails – or was never installed – the moisture keeps rising.
📌 Signs You Might Have Rising Damp
- Tide marks on walls, up to one metre high
- Peeling paint or wallpaper
- Warped skirting boards
- Musty smells near the lower wall area
- Mould or salt stains (efflorescence)
⚒️ Step-by-Step Guide to Treating Rising Damp
Step 1: Confirm It’s Rising Damp
Not all damp is rising damp. Other sources could include condensation or leaks. A professional surveyor will:
- Check damp meter readings
- Inspect the pattern and height of damp
- Identify if the DPC has failed or is missing
🧠 Top tip: Rising damp rarely goes higher than 1 metre.
Step 2: Remove Contaminated Materials
Plaster, paint, or timber affected by rising damp often needs to be removed. These materials absorb salts from the groundwater, which can keep drawing in moisture.
- Strip back plaster to bare masonry
- Cut out damaged timber or flooring
Step 3: Install a New Damp Proof Course (DPC)
There are a few modern methods for this:
| Method | How it Works |
|---|---|
| Chemical Injection | A damp-proof cream or fluid is injected into drilled holes in the wall to form a water-repelling barrier. |
| Physical DPC Replacement | Replacing old DPC with slate, lead, or plastic sheets (rare due to cost). |
| Electro-Osmotic System | Uses low-voltage currents to reverse moisture flow. Mostly for heritage builds. |
Chemical DPC is the most common and cost-effective for most UK homes.
Step 4: Allow the Walls to Dry
Drying takes time – sometimes months depending on how saturated the wall was.
- Use dehumidifiers and good ventilation
- Keep heating consistent
- Don’t replaster too soon
🧠 Top tip: A wall dries at roughly 1 inch per month.
Step 5: Replaster with Salt-Resistant Materials
You can’t use standard plaster after rising damp. It will absorb leftover salts and fail again.
Choose materials like:
- Salt-retardant plaster
- Renovation plaster
- Lime plaster (especially for older buildings)
These help the wall breathe and resist moisture.
💡 Bonus Prevention Tips
Here’s how to keep rising damp at bay once you’ve treated it:
| Issue | Action |
|---|---|
| Faulty gutters & downpipes | Clean regularly and check for overflows |
| Sloping ground | Ensure the ground slopes away from walls |
| Chimney leaks | Repair flashing and repoint with hydraulic lime |
| Poor airflow indoors | Install trickle vents or positive pressure ventilation systems |
| Inappropriate wall finishes | Avoid cement render and masonry paint; use breathable materials |
📊 Summary Chart: Rising Damp Causes and Solutions
| Problem | Likely Cause | Solution |
|---|---|---|
| Tide marks on lower walls | Failed or missing DPC | Install new DPC (chemical injection) |
| Damp patches after rainfall | Cracks, defective render or pointing | Repair and seal with breathable render |
| Warped floorboards or skirting | Ground moisture creeping up | Replace timber and install new DPC |
| Salt stains on plaster | Moisture carrying ground salts upward | Use salt-resistant or lime plaster |
| Musty odours in old buildings | Trapped damp air and poor ventilation | Improve airflow, consider PPV system |
👷 Need Help Treating Rising Damp?
At Damp and Mould Solutions Ltd, we’ve treated hundreds of properties across London – from listed stone buildings to 1930s terraces. Whether you need a new DPC, breathable lime plaster, or full damp survey – we’ve got you covered.
📞 Call us today for expert damp advice and quotes.
🌐 Visit Damp and Mould Solutions Ltd for more help and information.
