Damp beginning to show through paint on ceiling

Why Is Damp Showing Through Paint?

12 April 2021

Damp is a tricky problem. There are a number of potential causes of damp including condensation and structural faults, and each of these causes requires a specific solution being diagnosed by an expert. If you start noticing damp appearing through paint then, it can be confusing and hard to understand why your decoration is now suffering from the scourge of damp.

So, if you were wondering why damp is now showing through your properties painted walls, then this is going to be the article to help you.

Why Does Damp Show Through Paint?

The very first question you are going to have when it comes to finding damp appearing through your paint is ‘why?’. The answer to that question might appear simple, but it might lead to further questions and work from yourself.

First, the reason that there is damp appearing through the paint on your walls is because that the wall has become exposed in some way to excess moisture. The fact is that when you are seeing damp coming through the paint on your wall, that you have a clear and significant problem on your hands, and that understanding and solving it is paramount when it comes to not only taking care of how your property looks, but its actually structural integrity.

You will want to start by discovering exactly what kind of damp you have that is causing your paintwork to show signs of water damage. This might be easier than you first expect, though we do recommend getting a surveyor to look at the problem for an in-depth and professional evaluation.

If however, the damp is appearing through paint on the walls of a bathroom, kitchen, or washing room, then you may well be experiencing damp caused by condensation. Condensation can easily cause damp to appear in your walls and force its way into the paint, and it is especially prevalent within rooms that experience more condensation than most.

Untreated damp won’t just show through paintwork – it could destroy it.

Take a bathroom for example. The excess condensation that arises out of shower steam, from bathwater during an extended soak, or even just from a sink as someone is washing their face all contributes towards the overall condensation level within the bathroom.

If that condensation isn’t allowed to ventilate out of the bathroom properly, then what is likely to happen is the condensation will enter the walls of the bathroom, shift from a gaseous state back to a liquid state upon encountering the cooler air within your bathroom walls, and that liquid will come to rest within the walls themselves.

This is called interstitial condensation, and it’s a big cause of damp build up. The chances are that if you are seeing patches of damp appearing within a bathroom, or any room that sees a lot of condensation building up, then this is the cause.

Another primary form of dampness is rising damp. This is damp caused by a building fault rather than behaviour, and stereotypically presents itself when moisture from the ground (or pooling anywhere in contact with your property) travels upwards through the masonry as a result of capillary action.

This kind of damp is mainly found on exterior walls, and will definitely require specialists to not only survey, but treat with the installation of a damp proof course.

The final type of damp that could be causing water damage to your paintwork is penetrating damp. This is when water is consistently building up and entering your properties walls horizontally, rather than draining away in the proper channels as it should.

In these situations faulty guttering, broken masonry or even improperly installed drains can all be to blame – and once again you will need a specialist to help you deal with the damage and avoid issues occurring in the future.

These are the three leading causes of damp, and the three main reasons that damp might be appearing through your paintwork.

Your next biggest question is going to be how do I get rid of it?

How Do I Stop Damp Coming Through Paint?

The first step in stopping damp appearing in your paintwork is discovering what kind of damp is causing the patches to appear. The main kinds of damp were outlined in the last section, but to be entirely sure you should always call out a qualified damp proofing specialist to look at your property and identify not only the cause of damp, but put forward a realistic solution to the problem.

Once you have identified what is causing damp to appear through the paint, it will be time to get to the root of the problem.

In the case of rising damp, you may be advised to have a damp proof course installed in your property. With penetrating damp, you will need to stem the source of the moisture ingress before clearing up any damage the damp might have caused to the inside of your property.

Both of these situations place the property owner in a difficult situation, as there is no immediate fix that can be brought about without the help of a qualified expert. However, when it comes to damp caused by condensation, there are a number of steps that the occupant can take to reduce the moisture building up.

First, you should make sure that the room in which the condensation is building up within is well ventilated. That might mean opening windows and doors straight away to allow for a flow through of air, but in the long term, you may want to consider installing extractor fans to help remove the condensed air from the room safely, or even a positive pressure system to keep your property free of resting moist air at all times.

A positive pressure system like this one can help ventilation

This is the most vital step in preventing condensation from causing damp – allowing for the condensed air to ventilate properly. The second most important step is examining the behaviour of the properties inhabitants which led to the condensation issue and the resulting build up of damp that is now visible through your paint.

Changing daily actions might seem small, but it can have a large effect. Drying your washing outdoors, putting lids on boiling pots and pans, taking shorter showers or baths, or even just allowing for further ventilation once in a while can all act in alleviating the damp problem that’s making its way through your paint.

It’s also important that you act before any of the associated problems of damp have a chance to take root in your property. Associated problems include nasty side effects like black mould growing on damp patches. Black mould spores and not only be harmful to any occupants but also help spread the mould through the property.

Be sure that as you are treating your damp, you make sure to take provisions to clean away any black mould that has grown. You can find out more information on how to clean black mould here, but it needs to be eradicated correctly and completely.

Can I Just Paint Over Damp?


That’s the short answer, but if you wanted to know why, I think this blog has been pretty forthright in letting you know that damp is a problem located within your walls, rather than a superficial worry.

Painting over the damp that has appeared in a wall is not in any way solving your problem. At best you are giving yourself a little more time before the damp re-appears in the new layer of paint. At worst, you are giving black mould a larger surface area on which to fester and grow.

The kind of black mould problem that can appear if damp is left untreated


It is very important that before you redecorate, any and all aspects of your properties interior that have been affected by damp and (or) black mould have been treated effectively. This might even mean having plasterboard being replaced, but that’s ok

As long as the new materials are placed on walls that no longer suffer from the damp they once did, you will be free to apply a fresh coat of paint and continue your life with a focus on preventing damp before it gets to the same stage again.

Can I Use Damp Proof Paint?

Damp proof paint is always a possibility when it comes to installing measures that can potentially ward away the ill effects of condensation.

Damp proof paint can help stop interstitial condensation making its way through walls and resting within masonry, stopping the build up of damp resulting from heavy condensation. If applied within kitchens and bathrooms or other condensation heavy rooms, alongside the use of extractor fans or other more effective forms of ventilation, then you will have a fairly comprehensive defence against condensation led damp re-appearing.

It’s not just condensation that damp proof paint stops either. It is also a great way of ensuring that in the future (if your walls do fall victim to damp) that the patches never show up in the inside of the house through the paintwork.

This is great for two reasons. The first is the obvious fact that the paintwork on the inside of your property will not show damp patches on walls that you have painted should a damp problem re-appear. As a result it will help keep your property looking in tip top condition.

The second brilliant thing about this is that if your paint remains dry, it will be much more difficult for any black mould spores to settle and grow on top of it, making the interior of your property much more resistant to the fungus.

Drying Out Damp Patches in Paint

If you have addressed the root cause of your damp, and the only stage left is to dry out the damp patches that have appeared in the paintwork itself, you may be wondering what the most effective methods of drying out damp paint might be.

The answer is much the same as we might recommend for dealing with a heavy condensation problem. Ventilation is going to be a key facet in drying out damp patches within paint, so opening up windows and doors is going to help the situation vastly.

Another way in which you can help dry smaller damp patches in paint is with the use of fans. A fan could easily be used to dry out smaller damp patches, as long as the fan itself is of a adequate size and the damp patch is small and superficial enough that a fan could have an effect.

Finally, you can always consider using a dehumidifier. With the primary purpose of a dehumidifier being to absorb the excess moisture from the environment, they are ideal for helping to draw out and safely retain the moisture causing a damp patch to appear in your paintwork.

Worried About Damp Appearing Through Paint? Call An Expert

Have you found a patch of damp that is now appearing through your paintwork? Worried about why it’s appearing, or what the cause might be? You can always call our expert team for guidance and further support today.

Our local technicians are on hand to arrange fast, effective, and accurate property surveys which can help you understand not only why damp might be showing through your paint, but what is causing it, and how to stop it.

Call 0800 288 8660 today, or arrange a damp survey online via our form here.