Can I paint damp walls?

We get asked all the time by homeowners whose properties have interior walls impacted by issues like rising damp, so here’s the ultimate guide.

Put aside your thoughts of rendering your exterior walls for now and turn your attention to things like damp proof paint and anti-mould paint for your interiors.

Let’s dive in and take a closer look at everything you need to know.

Do I still need a damp proof course?

Yes, even though we’re looking at painting, a damp proof course is the only way to address the root causes of damp problem.

Let’s assume you have already contacted a Federation of Damp professional for help with a damp proof course and that you’re now weighing up whether to paint your interior walls.

Can I apply paint on very damp walls?

No, and in fact, you should apply paint to any damp patches at all, regardless of how minor they may appear.

Whether on your ground floor brick walls or plastered upper levels, the excess moisture will stop the paint from adhering and drying correctly.

Flaking paint, a persistent musty smell, and rotting skirting boards will soon follow, as will loose debris from internal walls as they continue to degrade.

There are, however, some prep steps you can do once the causes of the wet patches have been rectified by an expert who comes to your house to tackle damp on a deeper level.

Remove the mould stains

Rising damp and penetrating damp will both lead to mould growth and peeling paint, even when using an oil-based paint, and you need to put it right.

While anti-mould paint may sound like a cure-all solution, it’s there to form a water-resistant barrier against future mould, not to be used as one of the damp proofing products that kills off the initial mould growth.

Scrubbing gently with white vinegar mixed with baking soda, but only after a professional has finished treating damp throughout your property, is the way to go.

Patch up the cracks and holes

If the salt deposits aren’t so bad that you need to remove the plaster, you should be able to patch it up with a waterproof sealant from a hardware or DIY store.

Make sure you apply evenly across the surface and sand down so it’s flush with the wall before making sure to follow the manufacturer’s instructions so that it is fully dry before painting.

Apply a waterproof paint sealant

Preventing further mould is about being proactive even after the initial damp problem has stopped. While rising damp and penetrating damp require in-depth corrective action, you can further damp proof your repaired internal walls by applying a sealant before your damp proof paint.

Damp seal paint base layers like this will help reduce the likelihood of water ingress from occurring in the future.

Start painting once the sealant dries

Apply your damp proof paint in even layers, giving each coat sufficient time to dry, and you will be able to provide an aesthetically pleasing waterproof barrier to your home.

Now that you know how to prep your walls and get painting, we need to take a look at some of the other key questions so that you know all of the fine details.

Do You Need to Remove Plaster for an Injected DPC?

Yes, the removal of plaster may be required during injected DPC installation. Often, water damage to plasters is caused by contaminated salt. Removal or replacement of the plasters ensures a clean, dry base to prevent damping.

How can you fix condensation quickly?

Poor ventilation and cold air temperature are leading causes of damp walls that experience condensation. Opening a window, turning up the heating, and looking for leaking pipes are all simple things you can do.

For more in-depth water ingress issues, such as pentrating damp and rising damp, you will need to contact a damp proof expert. We can help you find them without delay!

Should you damp proof before plastering?

Yes, you need to treat damp walls with a damp proof before plastering otherwise, the plaster will crumble and crack and mold will grow rapidly.

How do you waterproof a wall?

Water-resistant membranes are used to line the walls, while a waterproof render may also be applied to the external surfaces.

Can you paint over damp?

Painting on damp surfaces traps excess moisture on the surface of the wall, resulting in peeling paint and paper, mould growth, and persistent musty smells. While it may look like a quick aesthetic fix for the issues caused by penetrating damp, damp proof paint should only be seen as the final repair once a damp proof course has been completed.

Does opening windows reduce damp?

While it reduces the smell of damp for a short period of time, it will do nothing to stop the water ingress that may be causing your issues. That said, opening your windows is a key step when painting as, provided it is a warm, dry day, it will help your paint cure and dry much faster.

Can I just paint a damp wall anyway?

We strongly advise against any plans you may have to paint over damp as it won’t solve the underlying issues, no matter how much better it looks in the short term.

How to treat damp walls before painting?

A damp course carried out by a suitably trained professional who has worked with the Federation of Damp is a far better approach than trying to patch things up or diving into DIY treatments.

What happens if you paint a wet wall?

The paint will trap excess moisture, resulting in a breeding ground for mould. It will also be much more likely to peel and flake off in the near future.