Damp proofing is a necessary measure in any wet room. From your kitchen to your bathroom, it’s essential to control moisture perfectly to prevent fungal decay and mould from taking hold.
As we’re amid a cost-of-living crisis, you might think it’s more cost effective to damp proof your home yourself, and you’d be right: There are plenty of products on the market that can help control or prevent moisture from going where it can cause damage.
However, while DIY products have a cost advantage over specialist repairs, they also carry the risk of causing further damage if your practical skills don’t match your enthusiasm.
In this blog, we’ll discuss what DIY damp proofing is, where these over-the-counter methods can go wrong, and what goes into correctly preventing damp within your home.
Why Damp Problems Are Not Always What They Seem
Damp is a symptom of a greater property maintenance problem; it’s rarely the full story and diagnosis. Whether you’re dealing with rising damp from the ground, penetrating damp from a defect, or condensation from inadequate ventilation, damp problems can manifest in several different ways.
When dealing with damp problems, it is essential that an issue is diagnosed correctly to ensure the ideal solution is applied to your situation. Identifying something incorrectly and then treating for the wrong thing can make damp issues far worse than if you’d just left them alone. For example, damp proof paint can seal water within timber or plaster, preventing it from evaporating. This can then lead to issues such as fungal decay or failed plaster.
It’s also important to recognise that damp issues might not even be your fault. If your neighbour has a damp issue, their attempt to fix it themselves might result in the damp transferring to your side of a party wall.
Common DIY Damp Proofing Solutions Homeowners Try
Here is a selection of common DIY damp proofing solutions that some of our clients have tried before seeking our expertise.
Damp Proof Paint
When new homeowners first begin their DIY journey, often painting is the first skill they learn. In water-producing areas like kitchens and bathrooms, damp proof paint is one such remedy that can reduce the amount of damp in a wall by creating a waterproof barrier on the surface.
Silicone-Based Sealant
Sealants are another waterproofing measure that can be easy and cost-effective to apply. In bathrooms, silicone sealants prevent moisture from leeching through gaps between the shower tray/bath and the wall, which could cause timber decay in the floorboards beneath or mould growth on the walls behind the fixture. Sealants can also be used to tidy up gaps on timber skirting boards or architraves, or in joints between windows and walls.
Anti-Damp Sprays
Anti-damp sprays are an aerosol sealant. When applied to walls and ceilings, this creates a waterproof barrier that prevents moisture, mould, or damp staining from showing on your wallpaper or painted wall.
Laying Plastic Membranes
Plastic membranes are an ideal method of preventing moisture transmission. You’ll commonly see these in damp proof courses in the walls of new build properties, or wrapped around timber ends (called ‘capping’) where the timber is in contact with masonry, which could allow moisture to damage the timbers if left unprotected.
Damp Proofing Rods
An alternative to a chemical damp proof course, damp proofing rods are fibre cylinders carrying a water-repellent chemical. These rods are inserted into the mortar joint of a wall at regular intervals. Once installed, they steadily release their chemicals along the mortar course, curing and forming a damp proof barrier within the wall.
DIY Tanking Kits
Basement and Cellar Tanking Systems can create waterproof storage spaces in your home, and it is possible to tank a cellar yourself. DIY tanking kits often come as a pre-mixed slurry, or as a powder to be mixed with water. This slurry can then be applied directly to masonry with a brush or trowel.
Improvised Ventilation Fixes
Passive ventilation is an integral part of keeping your home regulated from condensation and moisture build-up. It’s possible to install new wall vents or air bricks to improve the air flow within your property.
External Seal Coatings
Seal coatings come in a variety of materials, including asphalt, silicone, liquid rubber, or chemicals. Each one is suitable for use on a different area of your property, such as your driveway, walls, or timber window frames. Like damp-proof paint, each aims to seal the surface to prevent water ingress.
Why DIY Damp Proofing Often Fails
There are several reasons why DIY damp proofing methods often fail.
Mistake 1: Treating Symptoms Instead of Causes
Often, damp walls are a symptom of a greater problem, and are rarely the cause of an issue. For example, applying damp-proof paint to a wall might prevent the water from showing through that wall. However, it won’t solve the penetrating damp issue causing moisture ingress, and that moisture will likely appear elsewhere within the property. Many DIY solutions are ideal at hiding issues, but few are ideal at fixing the causes of damp.
Mistake 2: Incorrect Diagnosis
It is very easy to misdiagnose one case of damp for another. If you don’t know whether the moisture in your walls is down to a leak or condensation, treating for the wrong thing won’t fix the problem. Instead, it could cause the problem to appear elsewhere, or cause a greater issue down the line.
It is important to have your property professionally surveyed prior to any remedial work, whether your doing the work yourself or seeking the assistance of a contractor.
Mistake 3: Inappropriate product use
Many DIY solutions sell a one product solution to an issue. However, many damp problems require several different remedies to ensure complete protection against moisture-related issues.
Another concern is using the wrong product in the wrong place, or not using enough solutions to fully repair a defect. For example, installing a membrane in a basement without a drainage channel will just encourage the water to pool on or beneath the floor instead. Similarly, trapping moisture within a damp wall with a waterproof spray or paint will cause the masonry, plaster, and waterproof coat to decay more rapidly.
Mistake 4: Structural or ground conditions ignored
Another mistake homeowners might make is not assessing their property for structural repairs. Failed bricks, pointing, and gutters can all create gaps where water can find its way inside a property. It’s important to look out for warning signs such as bowing walls or slipped roof tiles, which can indicate areas of weakness within the structures of a property.
Mistake 5: Incorrect Installation
Possibly the most important reason for a DIY solution failing is through incorrect installation. If a damp proof coating isn’t applied fully or at the ideal thickness, this can create gaps where water may seep through even if you think the barrier is watertight.
Similarly, plastic membranes are designed to be thin and flexible, meaning they can be easily damaged during installation. Once installed, it could also become damaged if something is installed over it. For example, a membrane on a wall could be damaged by a timber wall plate if the fixing pierces the plastic layer, creating a defect through which water can penetrate.
Another issue is that the correct preparation methods aren’t used before applying these solutions. Applying new silicone without cleaning any mould will just allow the mould to grow through the new sealant. Similarly, applying damp proof paint to a damp wall will seal moisture within, causing the waterproof seal and plaster to deteriorate much faster.
The Real Dangers of DIY Damp Proofing
DIY damp proofing solutions don’t just represent a failure if used incorrectly; they can also cause serious harm to your property. Incorrect use of DIY damp proofing can lead to several issues, including;
- Trapping moisture within timbers, causing timber decay such as wet rot or dry rot
- Hidden mould growth behind paint or sealants
- Accelerated structural decay in timber and masonry
- A false sense of security
- Increased future repair costs
When DIY Damp Proofing Works and When It Doesn’t
DIY damp proofing solutions can be ideal if applied correctly. For example, applying new bathroom sealant is often more cost-effective than contracting a tradesman, and the tools are reusable once you have them. Regularly wiping down damp surfaces can also prevent condensation-related issues without the need for further repairs in some cases.
However, DIY solutions won’t cure every issue, and it’s important to understand when to use a DIY solution and when to employ the help of a specialist. Structural repairs or a failed damp proof course and rarely repairable without specialist training and experience, and attempting to repair a serious issue yourself can very easily make the problem worse and the repairs more expensive.
Why Professional Damp Diagnosis Matters First
Professional diagnosis, such as with a Timberwise damp and timber survey, will reveal the necessary measures require to repair a damp issue within your property. Moisture mapping with an electronic conductivity meter will allow a surveyor to plot areas of damp within a wall to help identify the likely cause. Similarly, a surveyor can use relative humidity data from a hygrometer to measure atmospheric moisture levels to diagnose a condensation issue. Using these methods will allow a surveyor to diagnose a damp issue correctly, whether it’s the result of condensation, rising damp, or penetrating damp.
Professional Damp Proofing Solutions
Timberwise offers bespoke damp proofing and condensation solutions for both domestic and commercial clients. Book a professional damp and timber survey with Timberwise to understand the true cause before spending on temporary DIY fixes.
If you suspect any structural damage, such as degraded wall ties, masonry, or structural timber decay, our surveyors can confirm a diagnosis and provide treatment plan to repair any defect and protect it from future damp-related issues.
Cost Comparison: DIY vs Professional
While every job is different, and we can’t provide an accurate price
A table or visual comparing:
|
Cost item |
DIY | Professional |
|
Diagnosis |
£0 | Cost of a Survey |
|
Treatment success |
Not guaranteed |
Guaranteed after survey |
|
Future damage risk |
High |
Low |
| Warranty | None |
Long-term guarantee (between 10-20 years) |
FAQs
Can I Damp Proof a Wall Myself?
Yes, it is possible to damp proof a wall yourself using products like damp proof paint and damp proof rods. You should request a survey to have a professional surveyor attend your property to diagnose an issue prior to beginning any work on your property to ensure you’re treating for the correct form of damp. Our partner blog has more information on Cheap Ways of Damp Proofing Your Home
Will Paint Stop Damp?
No, regular paint will only mask a damp issue, and the damp patches will soon return if you don’t fix the problem causing the damp. Damp proof paint will seals moisture within a damp wall, which can cause the plaster to deteriorate more quickly, or can cause damp to migrate into other areas of your property. For more information, check out our blog, Does Damp Proof Paint Work?
How Do I Know What Kind of Damp I Have?
There are also several overlapping symptoms of rising damp, penetrating damp, and condensation, such as damp patches on walls and musty smells. We recommend booking a survey to have your property diagnosed correctly prior to beginning any work.
What Is The Difference Between Rising Damp and Penetrating Damp?
Rising damp is often linked to external ground levels and a failed damp proof course. Penetrating damp is often associated with a defect such as a leaking roof or a plumbing leak.
How Long Does Professional Damp Proofing Last?
All Timberwise chemical damp proof course and timber treatments come with a 20-year guarantee as standard.
Does Brushing on a Sealant Help with Damp?
Yes, damp proof sealants can help with damp if applied correctly. Applying waterproofing solutions to a damp wall can seal the moisture within, causing greater damage and putting other areas of the property at risk.
Are DIY Damp Proofing Products Safe?
Yes, DIY damp proofing products are safe to use provided you follow the correct precautions. We recommend reading the instructions on the product prior to purchase to understand how they work, wear protective clothing during the task, and only use the correct tools recommended by the manufacturer.
