Does Damp Proof Paint Work?

Most of us will have dealt with damp problems at some point in our lives. Whether you’ve had condensation in your kitchen or rising damp up a wall, many of the UK’s properties have had a damp-related defect at some stage during or after construction. For every kind of damp problem, there are also several different ways to treat it, and applying damp proof paint is just one of those methods.

In this blog, we’ll discuss what damp proof paint is, what the ideal environment for the product is, and what can happen if it’s used in the wrong place or applied incorrectly.

What is Damp Proof Paint and How Does it Work?

Damp proof paint (also known as damp-seal or waterproofing paint) is a barrier coating that can be applied to walls. It can be applied in the same way as emulsion paint you’d use to decorate your walls. Once dry, the paint forms a barrier, sealing the surface of the wall and preventing damp from reaching the face of an internal wall.

Where can I use Damp Proof Paint in my Home?

Damp proof paint is ideal for use in areas that have a high moisture content. For example, it’s great for use in kitchens or bathrooms where moisture-creating activities like bathing, cooking or cleaning are prevalent. This is especially true if these rooms lack mechanical or passive ventilation to help disperse the moisture-rich air when you’re finished.

Damp proof paint can also cover damage such as tide marks from previously repaired leaks or damp. This will prevent the stains from showing through on the wall after you’ve redecorated.

Is Damp Proof Paint the same as Anti Condensation Paint?

Not quite, though they do share similarities. While damp proof paint is predominantly a barrier against moisture, anti-condensation paint also acts as an insulator. This makes it ideal for use on cooler external-facing walls, as it prevents warm moist air from beading on the surface as condensation.

Another difference is that damp proof paint is used to treat damage caused by a defect behind the plaster, such as from a leak or rising damp. Anti-condensation paint is more regularly used to treat water condensing on the surface of a wall, preventing outbreaks of fungal infestations like black spot mould.

Does Using a Damp Proof Paint Actually Work?

If used correctly, damp proof paint can provide a preventative barrier against minor damp concerns. However, it’s important to understand where it’s most effective:

• In cases of minor penetrating damp, where an external defect has been fixed, this can prevent staining from getting worse or showing through any decoration.
• In areas where containment is key over appearance, such as in garages or utility rooms, it can provide additional prevention against atmospheric damp.
• If used alongside additional damp prevention measures as part of a full system.

What Are Some of the Problems with Damp Proof Paint?

It’s also important to acknowledge where damp proof paint is not the ideal solution for a damp problem. For example:

• Applying it to a wall that is currently damp will increase the drying time of the product, and can trap excess moisture inside the wall. This water could eventually migrate to other areas of a room where it can cause additional damage.
• Where rising damp is prevalent, damp proof paint does not stop moisture rising into the masonry behind the paint. The constant source of moisture will draw more salts into the wall, and eventually cause the paint to break down.
• In cases of penetrating damp, an influx of water can increase water pressure behind the paint. This pressure can cause paint and plaster to blister and either peel away or trap the moisture.
• Damp proof paint doesn’t treat the root cause of condensation, and may make condensation worse by preventing walls from being able to breathe and release any built-up moisture.
• Damp proof paint can give the false impression of repair while a problem continues to cause untreated damage underneath.

Conclusion

Damp proof paint can provide adequate protection against damp-related damage when used alongside other treatments as part of a full system of damp prevention measures. Damp proof paint is ideal for covering stains as the result of previous defects such as penetrating damp or rising damp.

However, damp proof paint does not treat any underlying issue with damp, and using the product incorrectly can cause the product to fail or create further damage if any structural defects are left untreated.

Damp proof paint should not be your only treatment for a damp problem, and you should consult a specialist surveyor to confirm the correct cause and treatment for your unique situation prior to undertaking any remedial work in your property.

FAQs

Can I use damp proof paint on walls that are already damp?

Damp Proof Paint should be applied only on dry, prepared surfaces. Applying damp proof paint over existing damp will only mask a defect, and will cause the product to eventually fail.

What preparation steps are essential before applying damp proof paint?

You should remove any old paint or other coatings prior to applying damp proof paint. Ensure the surface is clean and clear of dirt and debris, and that the wall is completely dry before applying the product.

How do I know if damp proof paint is the right solution or if I need a specialist treatment?

Damp proof paint will only mask a structural issue, not cure the root cause. You should always seek the advice of a specialist surveyor or technician prior to applying damp proof paint to ensure there’s no defects causing a damp issue, as this could lead to further property damage. You can request a survey to have one of Timberwise’s specialists attend your property to provide advice on how to treat an ongoing damp issue.

How many coats of damp proof paint should I apply and when?

You should apply at least two coats of damp proof paint to a prepared surface to create an effective barrier against moisture. You can apply additional coats if damp stains continue to show once your first coats are dry. Consult your product for specific drying times (often 24 hours), but an applied coat should be completely dry before applying an additional coat.

Why is my damp proof paint peeling or failing after application?

Poor preparation, applying the product to a damp wall, ongoing moisture issues or incorrect application can all cause damp proof paint to fail. You should consult the product’s guidance and instructions prior to beginning work, and only apply the product in the circumstances required to prevent failure.