Damp surveyor discussing damp issue with the house owner

What Is Rising Damp And How To Treat It?

Key Takeaways

Rising Damp Overview: Rising damp is a serious issue for homeowners, causing damage to walls and impacting property value. It leads to problems such as mould growth, wet rot, damaged walls, eroding brickwork, and compromised plaster and paintwork.

Causes of Rising Damp: Groundwater is the main culprit, rising through capillary forces in materials like bricks, plaster, and timber. Lack of a damp-proof course (DPC), poor drainage, defective mortar, high humidity, and structural issues can exacerbate rising damp.

Signs of Rising Damp: Damp patches, peeling paint, crumbling plaster, salty deposits, musty smell, damp or cold walls, warped wood, and cracks in walls and foundations are common indicators.

Treatment Options: Internal treatment involves identifying and fixing the source, installing a DPC, replacing damaged plaster, improving ventilation, using dehumidifiers, and applying waterproofing sealants. External treatment includes repairing gutters, improving landscaping grading, applying waterproofing coatings, installing drainage systems, using permeable paving, and ventilating crawl spaces.


Let’s be honest – rising damp was, is, and always will be a menace for house owners. There are many reasons that support this statement. The first one is that it sneaks in, and the house owners themselves won’t even know until they see something huge happening.

Another reason is that rising damp not just comes with wet patches but also gives rise to mould growth, wet rot, damaged walls, eroding brickwork, damaged plaster and paintwork, etc. It sort of creates a promoting environment for other nasty things that can happen to the structure of your house.

There are so many houses in the United Kingdom that have been damaged due to rising damp issues, and some of them have even lost their property value. As insurance companies do not cover rising damp in their home insurance policies, treating rising damp becomes costly if it has gone to a severe level.

Due to this reason, it is important to treat the rising damp issue unless it is too late. But what treatment options are available for the rising damp problem? Well, there are plenty, and let’s see what they are.


Toxic black mould appearing near door frame in a house


What is Rising Damp?

Rising damp is an infrequent yet devastating symptom of moisture-related structural deterioration in building walls.

The condition is caused by the rise of moisture from the surface by capillary forces, which is similar to a liquid passing through a network of microscopic pipes, such as small openings in bricks.

As a result of capillary action, this water inflow takes a variety of salts with it.

It is critical to emphasize that not only are bricks involved in this moisture transmission, but also other porous structural parts such as plaster and the timber elements found in joists, baseboards, and skirtings located near the damaged wall.

This varied combination of materials has a noticeable tendency to collect groundwater, resulting in visible signs of damp rotting inside the wood.

The detection of rising damp is mainly based on the detectable adverse effects it has on the internal walls of the structure. It causes paint and plaster to deteriorate, while wallpaper loosens gradually.

Also, the water crystallizes into a visible stain on the external wall itself, leaving a clear appearance of a tide mark.

Salts, too, precipitate on the inner wall, with adverse effects on paint and plasterwork, often resulting in more damage.


Dampness and wetness penetrating through walls and ceiling


What Causes Rising Damp?

Rising damp silently causes damage to your walls and potentially impacts your health. Understanding its causes is critical to defeating it! The main culprit behind rising damp is groundwater.

Think of your property like a sponge sitting in a shallow basin of water (the groundwater). Water is naturally drawn upwards through tiny “tubes” within the sponge (capillarity) – in this case, the pores and cracks in your masonry walls.

If your property lacks a proper damp-proof course (DPC) – a barrier installed at the base of the walls to prevent this upward movement – groundwater will rise, saturating the lower sections of your walls.


Black mould stains on a wall


Other factors that can exacerbate rising damp are:

  • Lack of adequate drainage: Poorly maintained gutters, overflowing drains, or nearby slopes directing water towards your foundations can increase the level of groundwater around your property.
  • Defective or missing mortar: Cracks or gaps in the mortar between bricks or stones create pathways for water to penetrate the walls.
  • High humidity levels: Poor ventilation or inadequate heating can trap moisture in the air, encouraging condensation on walls and increasing the risk of rising damp.
  • Underlying structural issues: Cracks in foundations or walls can allow water to bypass the DPC and enter the building structure.

Rising damp typically affects the ground floor only, with damp patches appearing up to 1 meter from the ground. It often manifests as discoloured or peeling paint, plaster cracking, musty smells, and rising damp on internal or cold walls.

Ignoring rising damp can lead to severe problems like structural damage, wood rot, and mould growth, posing health risks.


What are the Signs of Rising Damp?

There are many signs that might indicate that there’s rising damp in your house. Here are some of the signs that are more prevalent:

Damp Patches and Tidemarks

Damp patches and tidemarks present as dark, often irregular stains on walls, resembling a high-water mark. These visual indicators serve as tangible evidence, highlighting the extent to which damp has permeated and affected the structural surfaces.


Rising damp on the corner of two walls


Discolored or Peeling Paint and Wallpaper

The impact of moisture becomes evident as paint and wallpaper lose their adherence, leading to cracks, flakes, and bubbles. The discoloured appearance and peeling are direct consequences of the loosening grip caused by the infiltrating damp.

Crumbling or Flaking Plaster

The structural integrity of plaster is compromised as moisture weakens its composition. This degradation manifests visibly in the form of crumbling and detachment, underscoring the detrimental effects of damp on the building’s interior surfaces.


Mould and dampness on walls


Salty Deposits

As damp evaporates, it leaves behind white, crystalline efflorescence – a clear indication of mineral salt deposits. These salty traces serve as a residual footprint, providing insight into the presence and movement of moisture within the affected areas.

Musty Smell

A persistent, earthy odour permeates spaces affected by excess moisture, serving as a distinctive olfactory cue. This musty smell is a reliable indicator not only of damp but also of the potential for mould growth, highlighting the importance of addressing the underlying moisture issue.


Dampness on ceiling which caused brick exposure


Damp or Cold Walls

Walls that consistently feel damp or cold to the touch signal the presence of lingering moisture. This tactile manifestation underscores the ongoing challenge of water retention within the structural elements, necessitating remedial action to prevent further damage.

Warped Wood

Under the influence of moisture, wood elements such as floorboards, skirting boards, and door frames undergo deformation. The pressure exerted by damp conditions can cause these components to buckle and twist, visually illustrating the structural impact of excess moisture.


Complete destruction of a store room due to dampness


Cracks in Walls and Foundations

Fissures in walls and foundations provide direct pathways for water infiltration, exacerbating the damp problem. These cracks not only compromise the structural integrity but also act as conduits for the continued ingress of moisture, emphasizing the need for timely repairs to mitigate further damage.

How to Treat Rising Damp?

The treatment of rising damp depends on the area in which it is present. Whether it’s inside the house or outside the home? Here are some options for the various rising damp problems present in both of these areas:

Internal Treatment for Rising Damp

First, Identify the Source

To find the source of growing moisture, conduct a comprehensive check or hire a damp surveyor. Repair any plumbing leaks, broken gutters, or other sources of excess moisture that may be contributing to the problem.

Install a Damp-Proof Course (DPC)

Installing a chemical DPC, which includes injecting a water-repellent solution into the problematic walls, is one option. During renovations, physical DPCs such as plastic or slate membranes might be constructed to form a barrier against rising moisture.


Excessive peeling of plaster work of a wall due to wetness


Replace Damaged Plaster and Skirting Boards

Any damp-affected plaster should be removed and replaced. To avoid future damp problems, replace the skirting boards with moisture-resistant materials.

Improve Ventilation

Improve natural ventilation by maintaining appropriate airflow in rooms. Install and operate extractor fans to lower humidity levels in kitchens and bathrooms.


Complete peeling of paint on a wall due to dampness


Use Dehumidifiers

Use dehumidifiers to remove excess moisture from the air, especially in wet environments.

Apply Waterproofing Sealants

To build an extra barrier against moisture, use waterproofing sealants on internal walls, particularly in basements or below-ground spaces.

Externally Treating Rising Damp

Repair Gutters and Downspouts

Check that the gutters and downspouts are clear of debris and in excellent working order so that precipitation may be directed away from the foundation.

Improve Landscaping Grading

Change the grading around the home to direct water away from the foundation. Create sloping landscapes to keep water away from the structure.


Damaged wall due to excess moisture content


Apply External Waterproofing Coatings

Waterproofing coatings can be applied to exterior walls to form a barrier against rainwater infiltration. For long-term endurance, consider cementitious waterproofing or elastomeric coatings.

Install External Drainage Systems

Install French drains or other types of drainage systems to collect and channel groundwater away from the foundation.


Peeling of plaster work due to dampness


Use Permeable Paving

Choose permeable paving materials for paths and driveways to allow rainwater to flow through the ground instead of pooling against buildings.

Ventilate Crawl Spaces

Maintain sufficient ventilation in crawl areas to minimize moisture buildup beneath the house.


Black mould stains on an interior wall


Repair Cracks in Walls and Foundations

To avoid water entry, repair any apparent breaches in external walls and foundations as soon as possible.

Landscaping Considerations

Planting trees or bushes too near to the home might cause foundation damage and contribute to moisture problems.


How to Prevent Rising Damp in a House?

Preventing rising damp in a house involves a mix of proactive actions to reduce moisture infiltration and safeguard the building’s structural integrity. Here’s how you can do it:

Damp Proof Course (DPC) Installation

A Damp Proof Course is a barrier built into the walls that prevents moisture from rising. Find out that your home has a properly installed DPC, which is often a layer of waterproof material, such as bitumen or plastic, inserted horizontally in the walls above ground level during construction.

Slope Away from the House

Make sure the land around your house slopes away from the structure to avoid water buildup near the walls.


Avoid the buildup of flower beds or soil against exterior walls, as this can allow moisture to penetrate.

Subfloor Ventilation

Adequate ventilation in the underfloor region aids in moisture prevention. Install vents or airbricks beneath the home to facilitate air circulation.

Room Ventilation

To prevent humidity, utilize extractor fans in kitchens and bathrooms to provide proper ventilation.

Inspect and Seal Cracks

In order to avoid water penetration, examine the outer walls on a regular basis for cracks and seal them as soon as possible.

Seal around Pipes and Cables

To avoid moisture infiltration, ensure that any holes constructed for pipes, wires, or other penetrations are adequately sealed.

Exterior Waterproofing

Apply waterproofing coatings or treatments to external walls to create an additional barrier against moisture.

Basement Waterproofing

If your house has a basement, consider professional waterproofing measures to prevent damp in below-ground areas.

Clean Gutters Regularly

Ensure that the gutters and downspouts are clear of debris to facilitate appropriate rainfall drainage away from the home.

Extend Downspouts

Extend downspouts to direct water at least 5-6 feet away from affected walls and the foundation.

Interior Sealants

Apply damp-proof sealants or coatings to the interior walls, especially in vulnerable areas like basements.

Use Vapour Barriers

Install vapour barriers on the interior side of walls to prevent moisture migration.

Timely Repairs

Regularly inspect the house for signs of damp and address any issues promptly. It includes checking for leaks, cracks, and any other vulnerabilities.

Proper Drainage

Plan landscaping to include proper drainage away from the house. Avoid creating low-lying areas where water can accumulate.

Consult Experts

If you suspect rising damp or encounter persistent damp issues, consult with a professional damp survey specialist. They can conduct a thorough assessment and recommend appropriate remedial actions.


The Bottom Line

Damp walls are frequently misidentified, especially by those without expertise. Identifying the specific type of damp affecting your property can be challenging for the untrained observer.

It is critical to correctly identify the source of moisture to avoid incorrect diagnoses that result in extra damage and avoidable costs.

It is always advised to see one of our professionals if you are unclear about the sort of damp problem you are experiencing. They will guarantee that your damp problem is effectively resolved.

A damp survey performed by Damp Surveyors Ltd.’s professionals is critical for dealing with growing damp quickly and efficiently. Hiring uncertified professionals may result in a misdiagnosis, resulting in a waste of your maintenance expenditure.

Property owners should try to keep their properties dry by getting rid of damp concerns in a prudent and cost-effective manner.

Damp Surveyors Ltd. has been helping house owners by identifying damp issues for years. So, call us right away if you are looking for a damp survey.


Can I treat rising damp myself?

Dealing with rising damp usually needs professional help. Although there are DIY products like damp-proofing creams, effectively solving the issue requires a deep understanding of its causes and the right remedies. It’s recommended to seek guidance from a qualified damp specialist or professional contractor who can accurately diagnose and provide a customized solution.

What kills rising damp?

To fix rising damp, you need to get rid of extra moisture and block further water absorption. Methods like injecting a chemical damp-proof course, installing physical damp-proof membranes, or using electro-osmotic systems are common. The best approach depends on your property’s specific situation. Consult with a qualified professional to choose the right method and ensure effective treatment.

What is the main cause of rising damp?

Rising damp happens when water from the ground moves upward through materials like brick due to capillary action. This is influenced by forces within the material that allow water to defy gravity. Issues like damaged damp-proof courses and poor ventilation around the foundation can make rising damp worse.

What is the permanent solution for rising damp?

To permanently solve rising damp, address symptoms and root causes. Use a damp-proof course via chemical injection or membrane application. Improve foundation drainage, enhance ventilation, and fix structural problems causing moisture. Consult a qualified damp specialist for a thorough assessment and a customized, holistic solution for a long-term fix.

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Sam Fitzgerald – CSRT Damp Surveyor

Sam Fitzgerald – CSRT Damp Surveyor

Author – CSRT Damp Surveyor
Sam is a highly qualified and seasoned damp surveyor with over ten years of specialised experience. With a strong academic foundation in building surveying and numerous professional certifications, Sam has established himself as an authority in the field of damp diagnosis and remediation.

At Damp Surveyors Ltd, Sam applies his extensive knowledge to help homeowners across the UK address and solve their damp issues effectively. His approach combines cutting-edge techniques with a commitment to honest, client-focused service, ensuring that every survey and recommendation is tailored to the specific needs of the property.

As a thought leader, Sam’s insights into damp prevention and treatment have been featured in industry publications, underscoring his role as a trusted expert dedicated to maintaining the integrity and comfort of your home.

Testing device for measuring dampness in a house


At Damp Surveyors Ltd, we stand out as your premier choice for damp survey services in the UK. Our commitment to excellence and customer satisfaction sets us apart. Here’s why you should choose us:

  • Exclusive 3 Free Quotes: We offer a one-of-a-kind optional service where you not only get our top-notch damp survey but also receive 3 free quotes from vetted local companies, giving you peace of mind by saving you thousands on getting the most competitive quotes, and also time researching and contacting other reputable companies.
  • Knowledge and Experience: We provide unmatched knowledge to every survey we conduct thanks to our team of seasoned professionals and years of industry experience. This guarantees accurate assessments and practical solutions.
  • Nationwide Coverage: Whether you’re in a bustling city or a rural area, our services extend across the UK, making us accessible wherever your property is located. Choose us for nationwide reliability and excellence.

Choose Damp Surveyors Ltd as your reliable partner for all-inclusive survey needs. Our top concerns are the health and safety of your property, and we are committed to providing outcomes you can trust.

Rising damp inside a house

What Causes Damp?

Key Takeaways Signs of Rising Damp: Damp patches on walls, often starting from the base. Salt deposits (efflorescence) in affected areas. Peeling wallpaper or paint. Musty smell. Causes of Rising

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