What Is Penetrating Damp?

Penetrating damp describes the process of water absorbing through exterior walls onto internal wall surfaces. Water penetrates a home when it passes horizontally through brickwork from sources such as rainwater or from groundwater through earth-retaining walls.

Believe you have penetrating damp?

The most common causes of Penetrating Damp are:

Building defects

  • Broken or missing roof tiles
  • Leaking gutters
  • Poorly installed windows
  • Damaged pointing
  • Faulty downpipes
  • Cracked external render

If the external components of your property (such as those listed above) are damaged, water may pass through them. These defects can be a sign that the structural integrity of your home is compromised; they may also be a tell-tale sign that your home suffers from penetrating damp.

Earth-retaining walls

Where walls are earth-retaining, such as the walls of a basement, a suitable barrier to stop water entering the home should be applied to these walls. Where earth-retaining walls lack suitable protection against penetrating damp, the internal wall surfaces will suffer.

An effective and lasting barrier to penetrating damp on earth-retaining walls is the ALLDAMP Membrane system. These membranes create a waterproof cavity system, which prevents damp making its way onto internal walls.

Brickwork which is exposed to the elements

Where brickwork is persistently exposed to rainwater, such as when a wall is persistently wet from striking rain, this can lead to moisture making its way into a home.

ALLDAMP Masonry Protection Cream is the ideal solution for brickwork which is exposed to the elements. It creates a protective barrier on your property, repelling rain and water.

Effects of Penetrating Damp

There are several signs of penetrating damp to look out for and they can take a while to appear, so it’s important to take action whenever you notice anything. Some signs are: localised dampness, plaster damage, wet rot decay, dry rot decay, mould, moss and brick damage.

Penetrating damp contributes to the humidity in a property, something which can affect the health of your family in time. High humidity increases the chances of condensation which in turn increases the chances of mould growth, which can cause respiratory health issues. This is particularly risky to the elderly, children, and people who suffer from asthma. Inhaling mould spores can inflame the airways, causing nasal congestion, wheezing, chest tightness, coughing and throat irritation. Prolonged exposure to damp and mould can reduce your lung function and lead to long-term problems. In your home, damp creates the perfect environment for the growth of dry rot; a wood-consuming fungus that can seriously damage the structure of your property, making it unsafe to live in.

Penetrating Damp Treatments we use

ALLDAMP Masonry Protection Cream

ALLDAMP Masonry Protection Cream is applied to the exterior of a property to repel rainwater and add to the insulation value of brickwork. It is a product that we consider when addressing issues with penetrating damp, providing walls which are exposed to the elements with an extra layer of water-repellent protection.

ALLDAMP Damp Proofing Membrane

Damp proofing membranes are a hardened material designed to provide a lasting, impenetrable barrier to stop water from damaging the wall. These sheets are installed behind plasterboard to provide a sealed barrier to stop water ingress. This is commonly used in cellars and basements.

If you’re looking to protect your basement from damp to turn it into a liveable space, we offer full basement conversion services.

Allerton ALL DAMP DPC Gun
ALLDAMP Chemical Damp Proof Course

Chemical damp proof courses are a fast and reliable way of inserting a new course into a property that has not previously had one, or one where the existing damp course is no longer effective.


How can I tell if I have penetrating damp?

There are various ways you might be able to spot penetrating damp. The first sign is often ‘wavey’ or damaged wallpaper, or crumbling plaster. You might also see wet or dry rot, mould or brick damage. If you suspect penetrating damp (or any form of damp) then call in the experts immediately. We can send out a qualified Surveyor to diagnose the problem and provide an accurate quote to get it sorted.

Is penetrating damp dangerous?

Penetrating damp in itself isn’t dangerous. However, in the long run, it does pose a lot of associated risks. For example, penetrating damp can lead to mould. In turn, black mould spores can impact the health of occupants, causing asthma and other respiratory problems that last beyond being exposed to the mould. Penetrating damp can also lead to issues with the building’s structural integrity. It means it’s extremely important to get in touch with an expert when you spot the first signs of penetrating damp.

How long does it take for penetrating damp to cause visible damage?

The time it takes for visible damage to occur due to penetrating damp can vary depending on the severity of the issue and the materials involved. In some cases, it may take months or even years for noticeable damage such as damp patches, mould growth, or plaster deterioration to appear. However, it’s important to address penetrating damp as soon as possible to prevent further damage and potential health risks.

Can I treat penetrating damp myself, or should I hire a professional?

Whilst there are some DIY methods available for treating penetrating damp, these are largely ineffective and it is generally recommended to hire a professional damp specialist. They have the expertise and experience to accurately diagnose the cause of the damp and implement the most effective treatment solutions. Attempting to treat penetrating damp without proper knowledge and equipment may not fully resolve the issue and could lead to further problems.

Can penetrating damp affect the value of my property?

Ultimately yes. Because of the structural damage that penetrating damp can cause, this can negatively affect the value of your property.

Potential future buyers of your property may be deterred because of the presence of penetrating damp within your home.

Find Your Local Damp Proofing Specialist

Contact Us To Book A Survey

Whatever your needs, a member of our Customer Care Team will be happy to hear from you. They are trained in all areas of our work from damp proofing to cellar conversions and will aim to help you as far as possible at the initial stage. They’re friendly, approachable and they always have time to discuss your property needs.


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