Damp walls are not only unsightly and can cause unpleasant odors, but they provide an environment in which mold spores can thrive.
Even without mold, damp walls can cause excessive moisture which promotes the growth of dust mites, cockroaches, bacteria, and viruses, which can have knock-on impacts on your health.
If you have a damp wall, you may be tempted to just paint over the damp patch.
However, not only will the water likely penetrate the new layer of paint, but painting over damp is not a solution to the root cause of the problem, and you need to get to the bottom of this before you paint.
A damp wall could be caused by excessive humidity, water damage, condensation, or a leak that is letting rainwater in.
Once you’ve identified the cause of your damp wall, you can then start thinking about repainting to cover up the damage.
There are some specific products that have been designed to protect your walls from further damage and to prevent mold and mildew from growing.
Best paints for damp walls
You need to ensure the walls are completely dry before you start remedying them.
Before painting your walls, apply a high-quality primer such as KILZ Premium Interior Primer, which will block out stains and odors,
Ronseal’s one-coat damp seal also brushes straight onto damp patches and permanently covers damp stains to stop them from ruining your paint.
These products will help conceal the water stains and will also provide a smooth surface for your paint application while preventing the stains from seeping through.
For the paint, you don’t necessarily need a damp-specific one, as most damp-repellent products fall under the primer category rather than paint.
Instead, you’ll need high-quality, 100 percent acrylic interior paint.
Behr or Benjamin Moore are great brands, as they’ll provide a smooth application and will be easy to clean. A satin or semi-gloss sheen is a good idea, because these finishes repel moisture, and can also be cleaned more easily than flat paints, which are far less durable.
How do you damp proof a wall before painting?
Find out what is causing the damp
Before you pick up your paintbrush or roller, you’ll need to determine what is causing your damp walls.
If the cause isn’t obvious, it’s worth getting a professional to properly diagnose it. It could be the result of blocked gutters, broken pipes, or poor ventilation.
Diagnosing and treating the damp issue is the first step to damp-proofing your walls. Otherwise, the issue will simply return and you’ll be stuck in the same predicament several weeks or months down the road.
Allow walls to dry out
While it can be tempting to cover up damp walls with a new coat of paint, allow the walls to dry out fully before repainting.
To speed up the drying process, you can direct fans at the wall or turn on your AC unit for a few hours.
If humidity is causing the damp, a dehumidifier can help suck out some of the moisture.
If the damp wall is in your bathroom, be sure to turn on the exhaust vent fan.
Prep your walls
Damp can cause bubbling, peeling, or other unsightly damage, and once your walls are dry, you can deal with these issues. Peeling paint should be scraped off.
You’ll also need to wash away any residue or dirt, but ensure you allow the walls to dry out again before you paint.
You should also fill in any cracks and holes and sand the wall until it’s smooth.
Prime and paint
Once your walls are completely dry and smooth, you can then apply your desired primer, ideally one that is stain and odor-blocking to disguise any watermarks left over from the damp. The primer will also provide a smooth surface for the paint to adhere to.
Follow the manufacturer’s instructions and allow the primer to dry fully before moving onto your paint application, and use a high-quality interior paint that has a semi-gloss finish to it so it blocks out moisture and can be easily cleaned.
It’s not nice to have damp in your home, and, if left untreated it can cause a myriad of issues.
Once you’ve found out the cause of the dampness, you can treat any leaks or humidity problems and allow your walls to dry out so that they’re ready to be repainted.
Thankfully, there are loads of great products on the market that are designed specifically to block out water stains and damage.
However, don’t forget that no matter how good the product is, unless you deal with the root cause of your damp walls, the damp will keep returning.