How Do I Stop Damp Showing Through Paint?

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how do I stop damp showing through paint

Damp patches can show on your wall for many different reasons. Whatever causes them they can all leave unsightly marks and can even lead to mould growth.

Dealing with the source of your damp should be your first priority. Once you have addressed the issue causing the damp you have a couple of options.

  1. You can dry the area and use a damp proof paint; this will cover any cosmetic issues and should stop the problem returning.
  2. Or if the cosmetic damage is only minor, and the issue causing it is fixed, you may get away with just drying out the damp patches.

The main point here is, the way to stop damp from showing through paint, Is to remove the source of the damp. Without dealing with the underlying issue your cosmetic repairs will probably be short lived. Prevention is vital for stopping damp from showing through paint. Repainting with damp proof paint can be a cost-effective way to remove the damp that is already showing,

What Causes Damp to Show Through Paint?

Damp shows through your paint when the wall has become exposed to excess moisture. The dampness in your wall can be caused by a few different things. Finding which type of damp you have is going to be important for treating it. It usually comes from condensation, rising damp, penetrating damp, or a defect with your roof, gutters, or pipes.

Any of those things can cause damp to show through paint. Condensation is most common in bathrooms, kitchens, and other rooms in your house that may have poor ventilation. It is caused by water in the air becoming trapped and turning to moisture on your walls. Here it soaks in and turns to damp patches.

Rising damp usually occurs at the bottom of your wall and rises upwards. This is caused by problems in your wall and damp proof course which allow water to be pulled upwards. This type of damp will often leave a white salt powder on your walls. This can also show through paint if it is severe enough. Penetrating damp is caused by water entering through your wall.

Your damp could also be from faulty pipes or problems with your roof or guttering. These can all cause damp patches in the area around them if they are damaged and letting water in.

All these sources can be the cause of damp showing through your paint. 

Can You Paint Over Damp with Normal Paint?

If you’re wondering how you can stop damp from showing through paint, then you might be hoping it’s as simple as painting over it with regular paint. Unfortunately, in most cases, this isn’t going to be enough. Simply painting over with regular paint will just briefly hide the problem. You will still have damp building up on your walls. The damp is going to soak back through the paint if not treated.

On top of this, you might find it difficult to apply regular paint to a damp patch that is consistently getting damper. Equally, if you have mould then simply painting over it just isn’t an option. Instead, you’ll need to remove the mould and deal with the damp patch underneath it.

Deal with the Source of the Damp First

If you want to know how to stop damp showing through your paint, the important thing is to deal with the source first. Covering up the damp to make your wall look nicer is only a temporary fix. If you don’t fix the source of the dampness in the first place, the damp will simply return.

To start with, you’ll need to figure out what type of damp you have. You can read more about the different types of damp along with some damp proofing solutions here.

Once you know the type of damp, you can start to treat the cause of it. This is the best way to stop damp from showing through your paint. Dealing with the root cause of your damp will stop the damp occurring in the future. Once this is sorted out, you can look at fixing the damp that is already there and covering up the cosmetic issues.

Using Damp Proof Paint to Stop Damp from Showing

The easiest way to deal with damp that is already showing is damp proof paint. This will waterproof your wall and fix the patches already there. This is the whole process:

  1. The first step is to deal with any mould. You can use a mould remover like this to remove the mould and make your wall safe to be painted. 
  2. Next, you need to make sure your surface is ready for painting. The dryer the damp spot is at this point, the better. However, it doesn’t have to be entirely dried out to apply damp proof paint. As long as it isn’t fresh and completely sodden to touch.
  3. Find great damp proof paint that is actually going to work. Our recommendations for the best damp proof paints can be seen here.
  4. Start to paint the wall! Most anti-damp paint is going to need more than one application. Apply the first coat over the wall. Damp proof paint goes onto the wall thick, so don’t be alarmed if it feels different going on compared with regular paint.
  5. Allow this to dry completely, how long this takes is going to depend on what type of paint you’re using.
  6. Apply a second coat if required.
  7. This last step is optional! If your paint can be painted over safely, paint over the damp proof layer to restore the original colour and look to your wall.

The process for applying damp proof paint is really quite simple. In some cases, you may have to dry out the damp first though.

Drying Out Damp Patches on Walls

If you have damp patches that have damaged the wall quite a bit, drying them out before you repaint will be beneficial. In minor cases drying out damp in the walls might set them right. Usually though, you will need to deal with the damage that has been done too. These are some ways you can dry out the damp patches on your wall to prep it for repainting:

  • Fans – Fans can be used to dry out smaller damp spots. You might have to run it for some time though.
  • Dehumidifier – A decent dehumidifier can help you to get the moisture out of your wall effectively. This is what you need to know about sorting out damp with a dehumidifier.
  • Ventilation – Opening up your windows and allowing the air to circulate in your house is great for drying out damp patches. If you have a lot of damp, then you might want to consider temporarily removing curtains around the window to ensure air circulation is the best it can be.

These solutions will speed up the damp on your wall drying out. Once they’ve dried, you will probably still need to repaint to get your wall looking its best though.


Damp showing through your paint can come from a lot of different sources, treating that source is your first step to stopping it. Once you’ve dealt with the root cause, you can actually get down to fixing the cosmetic issue of the damp patches coming through your paint.

Repainting your walls isn’t going to be enough. Take some time to dry out the damp patches and use a damp proof paint on the wall. This can effectively protect your walls in the future and deal with your current damp problem.