Rising Damp: Identifying the Signs and Addressing the Problem

Rising damp in your property happens when groundwater moves up through a building’s walls. This type of damp predominantly affects ground-floor walls and can cause severe damage to the whole property if not treated. Signs of rising damp can often be confused with other damp problems, such as penetrating damp or condensation, so correctly identifying it is very important.

Any homeowner must look out for the following common signs of rising damp. Let’s learn how to treat rising damp and understand its impact on property ownership and insurance.

What Are the Visible Signs of Rising Damp?

Below are the most common visible indicators:

1. Damp Patches on Walls

If you spot any damp patches on the walls, you may have a rising damp problem. This can be one of the most precise indicators of rising damp. These patches often appear as irregular stains and are typically located up to one metre above ground level on internal walls. They result from moisture from rising damp being absorbed into the masonry.

Damp higher than a metre on a wall could well be penetrating damp or condensation. However, a professional damp survey can provide certainty.

2. Tidemarks

Damp evaporation and salt migration form tidemarks on walls. These brown or yellow horizontal stains run parallel to the floor. They occur because rising damp carries groundwater salts that crystallise as the moisture evaporates.

3. Peeling Wallpaper or Paint

Peeling wallpaper or paint (especially on skirting boards) can be a key damp sign. If a wall is continually wet, the glue holding the wallpaper can come loose or bubble. A damp survey is still recommended here as it can indicate penetrating damp or condensation.

4. Bubbling or Flaking Plaster

You may see the plaster on your walls bubbling, crumbling, or flaking. These signs could mean the plaster’s structural integrity has been compromised. Over time, this damage can lead to the complete deterioration of the wall surface.

5. Salts Deposits

Hygroscopic salts are carried upward by rising damp and remain on the surface as the moisture evaporates. These deposits are an obvious sign of damp. Salt-contaminated areas can attract even more moisture, worsening the damp problem.

6. Musty Smell

Rising damp almost always has a musky, unpleasant odour. The smell of damp is an excellent non-visual clue.

7. Rotting Skirting Boards and Flooring

If a damp issue is left untreated, the excess moisture can lead to rot in wooden elements like skirting boards and floorboards. Signs of rot include cracks, crumbling wood, or visible fungus.

Causes of Rising Damp

How Does Rising Damp Occur?

Groundwater rises up through ground floor walls made of porous materials like brick and mortar through a process called capillary action. Water molecules are attracted to the surfaces of these materials and each other, allowing moisture to rise through tiny channels within the masonry.

What Causes Rising Damp?

• No Damp Proof Course (DPC): Modern buildings must follow building regulations that allow for effective damp proof course. However, older properties may not have DPC installed.
• Failing Existing DPC: DPC can break and fail if it isn’t maintained regularly.
• High Groundwater Levels: High water tables or poor drainage can make your property susceptible to rising damp.
• Cracked Masonry: Damaged mortar joints and cracked bricks can open up places for moisture to get in.

Professional Damp Survey

A damp survey of your home conducted by a damp surveyor provides a definitive diagnosis. Using moisture meters and other tools, a specialist can confirm what kind of damp issue you might be dealing with.

Treating Rising Damp

1. Installing a New Damp Proof Course

The most effective way to stop rising damp is by installing a new damp proof course. This involves creating a barrier to block moisture from travelling upward. Common methods include:

• Chemical Damp Proofing: A silicone-based solution is injected into the walls to form a water-resistant layer.
• Physical Damp Proof Course: Plastic or slate sheets are embedded into the masonry to prevent moisture from rising.

2. Removing Salt-Contaminated Plaster

Plaster affected by hygroscopic salts must be removed and replaced. A salt-resistant render ensures the wall remains dry and protected from further contamination.

3. Damp-Proof Membranes

Applying a damp-proof membrane to walls or floors provides additional protection, particularly in areas prone to severe damp problems.

4. Improving Drainage

Addressing external factors such as poor drainage and damaged gutters can help reduce groundwater levels and minimise the risk of rising damp.

Is Rising Damp Covered by Insurance?

Rising damp is generally not covered by standard home insurance policies. This form of damp is considered a maintenance issue rather than accidental damage. Insurers typically classify rising damp as a result of neglect or poor property upkeep, such as failing to maintain gutters or repair cracks in walls.

Buying and Selling a House with Rising Damp

Selling a House with Rising Damp

When selling a property, it’s a good idea to be transparent about any damp issues. Buyers will probably conduct a survey, and hiding the issue can complicate the sale. Addressing the damp issue beforehand, such as installing a new damp proof course, can make the property more appealing.

Buying a House with Rising Damp

If you’re considering buying a house with rising damp, you should understand that it is a manageable issue. A professional damp survey ensures you understand the extent of the problem, and the cost of rising damp treatment can often be factored into price negotiations.

Preventing Rising Damp

Prevention is the best defence against rising damp. To protect your property:

• Ensure your original damp proof course is intact and functioning.
• Maintain proper drainage to divert water away from the foundation.
• Inspect external walls for cracks or damage.
• Regularly check for early evidence of rising damp, such as damp patches or a musty smell.

Conclusion

Rising damp is a serious damp problem that can cause significant damage if left untreated. By recognising the signs of rising damp—such as tide marks, peeling finishes, and salt deposits—you can act quickly to resolve the issue.

Whether it’s through professional damp proofing, removing contaminated plaster, or improving drainage, effective solutions exist to protect your home. If you suspect rising damp in your home, contact local rising damp specialists for accurate diagnosis and reliable treatment options.