Rising damp happens when moisture from the ground moves upwards through the walls of a building. If it is not dealt with, it can damage plaster, paint, wallpaper, skirting boards and other materials close to floor level.
Good drainage, suitable ground levels and a working damp-proof course can all help prevent problems. It is also important to identify the real source of moisture before any repair work begins.
What Is Rising Damp?
Rising damp is moisture that travels upwards from the ground through porous building materials such as brick, block, stone and mortar.
The moisture can carry salts from the ground and masonry. As the wall dries, these salts may remain on the surface and can damage plaster and finishes.
Rising damp normally affects the lower part of a wall. However, not every damp patch near a floor is rising damp. Leaking pipes, high outside ground levels, rainwater problems, condensation and penetrating damp can create similar signs.
How Common Are Damp Problems in England?
The latest English Housing Survey figures show that 1.4 million homes in England, or 5%, had a damp problem in 2024.
Overall damp was most common in the private rented sector, where 10% of homes had a damp problem. This compared with 7% of social rented homes and 4% of owner occupied homes.
Rising damp itself was recorded in around 1% of homes in 2024. Severe condensation was more common at 3%, while penetrating damp affected around 2%.
Separate English Housing Survey findings for 2024 to 2025 found that 142,000 households, or 0.6%, lived in homes with the most serious Category 1 damp and mould hazards.
- 1.4 million homes in England had a damp problem in 2024
- 5% of all homes had a damp problem
- 10% of private rented homes had damp
- 7% of social rented homes had damp
- Rising damp was recorded in around 1% of homes
These figures cover all significant damp problems recorded by surveyors, not only rising damp. They show why it is important to check the cause before choosing a treatment.
The English Housing Survey also found that damp was more common in homes with poor external elements, internal disrepair or inadequate ventilation. A careful inspection should therefore consider the whole property rather than focusing only on one damp patch.
Keep Outside Ground Levels Below the Damp-Proof Course
One of the most important ways to reduce the risk of rising damp is to keep soil, paving and other outside surfaces below the damp-proof course.
Historic England advises keeping ground levels at least 150 millimetres below a known damp-proof course, or below the internal floor level where appropriate.
Problems can develop when patios, paths, flower beds or driveways are raised over time. Moist ground may then sit above the damp-proof course and allow water to reach parts of the wall that were meant to stay dry.
Check the base of outside walls regularly, especially after landscaping or paving work. If ground levels are too high, professional advice may be needed before they are lowered.
Read our related guides for identifying and preventing damp:
Check the Damp-Proof Course for Bridging
A damp-proof course is a layer designed to stop moisture travelling upwards through a wall. In many modern buildings it can be seen as a thin line in the mortar near the bottom of an outside wall.
A damp-proof course may be working properly but still be bypassed by other materials. This is called bridging.
Look for Raised Soil and Paving
Soil, paving or concrete that reaches above the damp-proof course can give moisture a route around it.
Check Render and Plaster
Render or internal plaster can sometimes extend across the damp-proof course and create a path for moisture.
Inspect Wall Cavities
Debris within a cavity wall can also allow moisture to cross from the outer wall to the inner wall. A suitable survey may be needed to confirm this.
Keep Gutters, Downpipes and Drains Working Properly
Water around the base of a property can increase the amount of moisture held in the surrounding ground and walls.
Clear leaves, moss and other debris from gutters so rainwater can flow away freely. Repair gutters that leak or overflow onto walls.
Check downpipes for cracks, loose joints and blockages. Water should discharge into a suitable drain rather than collecting beside the building.
Blocked or damaged drains can also keep the ground around a wall wetter than normal. Persistent pooling, bad smells or unusually wet soil may need further investigation.
Direct Surface Water Away from the Building
Paths, patios and other hard surfaces should not encourage rainwater to collect against an outside wall.
Check what happens during heavy rain. If water regularly flows towards the property or forms puddles beside the walls, the drainage or surface levels may need attention.
Keep gullies and drainage channels clear. Make sure garden landscaping does not block existing routes that carry water away.
Do not assume that adding a waterproof coating to the wall will solve the problem. Trapping moisture can hide the cause and may make some types of wall harder to dry.
Older and traditionally built properties can need a different approach, so suitable advice is important before changing drainage, wall finishes or ground levels.
Repair Leaks Before Treating the Wall
A leak can create damp near floor level that looks similar to rising damp. Treating the wall without fixing the leak will not remove the source of moisture.
Check nearby water pipes, radiators, heating pipes, washing machines, sinks and bathrooms for signs of leakage.
Outside the property, inspect rainwater pipes, external taps and drains. Slow leaks can be difficult to notice but may keep masonry wet for long periods.
If the water meter continues to move when no water is being used, there may be a hidden leak. Your water supplier or a suitable professional can advise on further checks.
Allow affected materials time to dry after repairs. Drying can take longer in thick walls and older buildings.
Do Not Confuse Rising Damp with Condensation
Condensation forms when warm, moist air meets a cold surface. It often affects windows, outside corners, bathrooms, kitchens and areas behind furniture.
Rising damp usually starts at low level and is linked to moisture coming from the ground. Condensation can appear at many heights and may be worse during cold weather.
Ventilation, steady heating and removing excess indoor moisture can help control condensation, but these steps do not repair a failed or bridged damp-proof course.
If there is mould high on walls or around windows as well as low-level damp, more than one moisture problem may be present.
A proper diagnosis helps avoid spending money on a treatment that does not match the cause.
Recognise the Common Signs of Rising Damp
Rising damp tends to affect the lowest part of an internal wall. The pattern may be fairly even across a section of wall, although the exact height can vary.
Possible signs include peeling paint or wallpaper, crumbling plaster, damaged skirting boards and a visible change in colour near floor level.
White or powdery salt deposits may appear as moisture evaporates from the wall. Some salts can continue to attract moisture from the air even after the original source has been repaired.
A musty smell may also be present, although this alone does not prove that rising damp is the cause.
Because several other faults can create similar symptoms, visible signs should be treated as reasons to investigate rather than proof of rising damp.
Be Careful with Damp-Proofing Treatments
A chemical damp-proof course is sometimes used where a suitable existing damp-proof course has failed or is missing. However, it should not be the first response to every low-level damp problem.
Before treatment, the cause should be identified and simple faults such as raised ground, blocked drainage, leaking pipes or bridging should be ruled out.
Some treatments also require damaged salt-contaminated plaster to be removed and replaced with a suitable system. The correct work depends on the wall construction and the source of moisture.
Older buildings may have solid walls made with materials that manage moisture differently from modern cavity walls.
For traditional or historic buildings, seek advice from someone who understands the original construction before adding injected barriers, waterproof coatings or dense cement-based finishes.
Know When an Older Building Needs a Different Approach
Many older properties were built before modern damp-proof courses became standard. They may use solid walls, lime mortar and other materials that allow moisture to move and evaporate naturally.
Historic England warns that raised ground levels and unsuitable modern materials can contribute to damp in older buildings. Dense cement render, waterproof coatings and other materials that limit drying may trap moisture where a more breathable finish was originally used.
Do not assume that an older wall must be injected with a new damp-proof course simply because it feels damp.
Start by checking rainwater goods, drainage, ground levels, leaks, ventilation and previous alterations.
If the property is listed, traditionally built or has solid walls, a surveyor or building professional with suitable experience can help choose repairs that match the building.
- Damp marks that start at floor level
- Peeling paint, wallpaper or damaged plaster
- White, powdery salt deposits on masonry or plaster
- Rotting, softened or stained skirting boards
- A visible damp line across the lower wall
- Outside ground or paving close to the damp-proof course
- Persistent damp after obvious leaks have been repaired
- Repeated damage to finishes in the same low-level area
These signs can point towards rising damp, but they can also have other causes. A moisture meter reading on its own may not identify where the water is coming from.
If the problem is persistent, widespread or causing damage to timber and plaster, arrange a detailed inspection before paying for major damp-proofing work.
Arrange a Proper Damp Survey
A good damp survey should look for the source of moisture rather than simply record that a wall is damp.
The inspection should consider the age and construction of the building, outside ground levels, the damp-proof course, drainage, gutters, pipes, wall finishes and signs of condensation.
Moisture readings can be useful, but they should be considered alongside the condition of the building and other evidence.
Ask the surveyor to explain what has caused the problem, what evidence supports the diagnosis and which repairs should be completed first.
For an older or traditionally built property, choose someone with experience of that type of construction.
Maintain the Property to Prevent Damp Returning
Prevention is easier when small maintenance problems are dealt with before they allow large amounts of water into the building.
Inspect gutters, downpipes and drainage several times a year and after severe weather. Remove blockages and repair leaks promptly.
Keep soil, flower beds, paving and stored materials away from the damp-proof course and air vents. Avoid piling compost, timber or other damp materials against outside walls.
Watch for cracked render, damaged pointing and gaps around external pipework that may allow rainwater to enter.
After building or landscaping work, check that outside levels and drainage routes have not been changed in a way that sends water towards the property.
What Should You Do if You Find Rising Damp?
Start by recording where the damp appears and when it becomes worse. Check both sides of the affected wall where possible.
Look outside for high ground levels, damaged gutters, leaking downpipes, blocked drains and standing water. Check inside for plumbing leaks and signs of condensation.
Do not cover the area with waterproof paint or new wallpaper before the source has been found. This can hide signs that are useful during an inspection.
Arrange professional advice when the cause is unclear, the damp keeps returning or timber and plaster are being damaged.
Once the cause has been repaired, allow suitable drying time before redecorating. The correct finish will depend on the wall and any salts left in the plaster.
Follow the links below to book damp proofing services for properties throughout Bedford, Luton, Bedfordshire or Buckinghamshire:
Rising Damp Treatment
A professional survey can identify whether moisture is rising from the ground or coming from another source. The findings help guide the correct treatment.
Cellar Tanking
Cellar tanking helps keep basements dry by creating a waterproof barrier that stops moisture from entering through walls and floors.
Timber Treatment
Our timber treatment service protects wooden parts of a property from rot, damp and insect damage, helping them stay strong and last longer.
Damp Proof Course Installation
Damp proof course installation helps protect a property from unwanted moisture and the damage it can cause.
Basement Conversions
Basement conversions turn unused lower-ground spaces into dry, practical rooms for living, working or storage.
Damp Surveys
Damp surveys identify moisture problems, their likely causes and the treatment needed.
Frequently Asked Questions
```How High Can Rising Damp Travel?
Rising damp normally affects the lower part of a wall, but there is no single height that proves the diagnosis. The pattern depends on the materials, salts, evaporation and surrounding conditions.
Can High Outside Ground Levels Cause Damp?
Yes. Soil, paving or concrete that sits too high can bridge a damp-proof course or allow moisture to reach the wall above it. Keeping suitable clearance can reduce this risk.
Does Every Damp Wall Need a New Damp-Proof Course?
No. Leaks, drainage faults, high ground levels, penetrating damp and condensation can create similar symptoms. The source should be identified before a new damp-proof course is considered.
Can I Paint Over Rising Damp?
Painting over a damp wall does not remove the source of moisture. The cause should be repaired first, and the wall should be allowed to dry before suitable finishing work is carried out.
How Can You Prevent Rising Damp Problems?
Keep outside ground, paving and soil below the damp-proof course and make sure air vents remain clear.
Maintain gutters, downpipes, drains and outside surfaces so rainwater is carried away from the building rather than collecting beside the walls.
Repair plumbing and drainage leaks promptly. Check low-level damp carefully rather than assuming it must be rising damp.
Avoid covering walls with waterproof finishes before the source of moisture is known, especially in older properties that were built with more permeable materials.
Inspect the base of walls after landscaping, extensions or paving work because changes to ground levels can create new moisture routes.
If damp continues, arrange a suitable survey. Correct diagnosis and regular maintenance are the best ways to stop a small moisture problem becoming a larger and more expensive repair.
Good property maintenance can help prevent moisture problems and protect walls, plaster and timber from avoidable damage. Aquafoss recommends dealing with leaks, drainage faults and other building problems early and arranging suitable professional advice when the cause of damp is unclear.
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