Home Trouble: How To Treat Damp Walls Internally Like A Pro

Do you have black, uninviting mould crawling up your walls? Well, you can always clean that mould off your walls or even your bathroom but this isn’t a permanent solution! It is probably an indicator that you have damp all over them. Damp walls are a real pain – not only they look visually unappealing but the dampness and moisture can also cause many troubles. Mould is just the beginning.

A white wall full of mould

If you have allergies or asthma, then this mould can have harsh health effects. Moreover, damp walls make your house feel uncomfortable, cold, and humid. Want to get rid of the damp feel and moisture ruining your walls? In this article, we tell you how to identify the problem, what are the common causes, and how you can treat them like a pro. Excited? Let’s read on!

How do you know that you have damp problems?

If you have a damp brick wall problem, there will be a couple of warning signs. Before anything else, let’s see what those warning signs are when it comes to the affected area

1. Look at the walls

Place your hand against the affected wall. Does it feel damp or cold? Search for signs of fungal growth or mould that will appear in the form of grey spots or black speckled marks. Curling wallpaper or flaking paint are also signs of damp walls.

2. Pay attention to the ceiling

When you are searching for signs of mould, take a look at the colour of the ceiling. Is your ceiling stained or discoloured in areas? There will be brown damp patches in the corners as well as near the chimney breasts.  

3. Search for condensation on windows

If there is condensation on your windows in the morning, and there are small water puddles along the window sill, this means that the level of moisture in your home is high. This is a cause as well as a symptom of a damp wall. You may also find black mould growth around the PVC and wooden window frames.

A wall next to a window full of mould

4. Take a look in your kitchen and bathroom

Search for mould on the ceilings, window frames, and the walls of your kitchen & bathroom. Don’t forget to check inside the cupboards and the cabinets as well. Moreover, pay special attention to humid or musty smells.

5. Furniture and furnishing

If you have damp walls, there will be black mould on the inside of your curtains and blinds. The same might happen to your sofas and upholstered chairs. Check the furniture for black mould spores and also keep an eye out for cloudy condensation on plastic & wooden surfaces. You can also get a damp meter – they are handy little gadgets that have an indicator on the front and two prongs on the base. Simply stick the prongs into the wall surfaces and after a while, you will be able to see the percentage of moisture within your walls!

What is the cause of damp walls?

Wondering what is the cause of damp walls? Well, as a matter of fact, there is not a singular cause but rather multiple ones. In most spaces, damp walls are caused by one of the following.

1. Poor ventilation

In any house, moisture is unavoidable due to cooking, washing, laundry, and even breathing. For a home to feel comfortable and dry, the moist air requires a way to escape that space. If there is no way for the moist air to escape, it starts to accumulate and dampen your walls.

2. Penetrating damp

Sometimes damp and moisture penetrates the walls from outside. These damp issues are mostly happening because the house has bad weatherproofing. Leaking roofs, leaking gutters, damaged mortar, etc. on the exterior walls are the causes of this.

3. Leaking plumbing

If the plumbing in your home is loose or old, it can cause leaking. Moreover, there can be an issue with the wastewater pipework or the central heating pipes that cause the water to slowly trickle out.

water on wooden floor coming from leaking radiator

4. Rising damp

Rising damp is usually an issue in old houses that don’t have damp-proof courses or don’t have substantial damp proofing. This means that the interior walls will absorb the moisture from the groundThis allows the damp to rise from the ground level to the walls of the house. Plus, if you have added insulation, modern plaster, doors, or windows recently, it might have weakened the ability of the building to breathe which traps moisture within the walls.

How to treat damp walls internally

Now that you know how to identify damp on your walls and a few factors that cause it, here comes the million-dollar question: How to treat damp internal walls? There are a couple of ways you can do that. You can go with damp proofing and waterproofing injection cream. There are complete kits as well as individual cartridges.

Once the cream is injected into the holes in your mortar, it takes a liquid form which allows it to penetrate bricks easily and get absorbed completely. As the cream cures, it creates a strong, water-repellent barrier. The chemical DPC in the cream stops moisture from rising up your outside walls. You can also install a damp proofing course but this is a complicated process in which you have to take out every brick along the damaged area and then place a damp proof membrane.

  • Treating rising damp

If you have a rising damp problem, then you need to improve the drainage of the area where your home is located. Ensure that there is enough space under your floorboards so that the moisture from the soil below can evaporate. Plus, replastering the walls and redoing the paintwork will help with the water ingress and damp build-up. Paint your walls with mould-resistant emulsion paint. It will add a layer of damp proofing to your internal walls

close up to person painting, using a paint roller in the paint tray, wearing protective cover for clothes

  • Treating penetrating damp

If you are facing the issue of penetrating damp, then you need to take measures to stop it from penetrating the inner walls. Seal all the gaps around the door frames and windows. If there is any damaged guttering, or if you have any missing roof tiles, replace them. If you see any evidence of crumbling mortar, you should hire a professional to make the repairs. A professional would identify the cause of damp and pull together a damp treatment plan for you after doing a damp survey.

How to prevent it and avoid all the trouble

Isn’t prevention better than cure? So, why not try to prevent dampness instead of trying to treat it later? You would be happy to know that there are several DIY measures that you can take to prevent and treat damp walls very easily.

1. Stay on top of home maintenance

Keep checking your roof regularly for any damage, especially during harsh, rainy weather. Keep your gutters clean and as soon as you have any damage, fix it. You can get gutter-cleaning tools to help you with this. Also, you should install gutter guards so that leaves and debris would stay out. 

2. Use dehumidifiers

There are so many benefits of using a dehumidifier. If there is excess moisture in your home, you should remove it using one. Go for a smart dehumidifier that automatically senses the change in moisture so that it will have no time to cause damage to your walls. Consider using a window vacuum to remove the condensation that develops on windows in the morning. If you don’t have one, you can simply wipe the windows with chamois leather to help your room dry out quickly.

A dehumidifier in a room traping all the moisture

3. Keep your home warm

When is condensation formed? It forms when moist, warm air touches a cold surface such as a cold wall or a chilly windowpane. Install loft and wall insulation so that you will have a warm place without any condensation. You can also fit double-glazing to avoid misty windows in cold weather. It is important that you maintain a constant temperature in your home to avoid any sudden rises and dips in it. 

If it has been quite some time since you had a look at your central heating system, do that and see if you need to make any changes such as getting thermostatic radiator valves or programmable thermostats, etc.

4. Ensure that your home is ventilated

We discussed above that poor ventilation is a cause of damp walls. So when we say that you need to improve the ventilation system of your house, it shouldn’t come as a surprise. Provide a route for the moisture to escape to reduce condensation.

Check that your washers and dryers are installed and vented correctly and that there are extractor fans in the bathrooms. If there isn’t an exhaust fan in your washrooms and kitchens, install one. Run it regularly so that moisture is cleared from the room. Something as simple as keeping the windows open, whenever possible, can help. 

5. Get moisture-resistant paint or wallpaper

Is your home prone to condensation or dampness? You should consider getting paints or wallpapers that will prevent and treat damp walls. There are paints and wallpaper specifically designed to resist steam or moisture – really helpful for bathrooms and kitchens. These paints don’t only keep mould at bay but are also easy to clean in case any mould develops. Go with vinyl wallpaper since it is splash-proof and is pretty easy to clean.

A woman looking at her damp wall that is full of mould


If you have damp walls, not only will you feel cold and uncomfortable, but the damp will also cause your allergies to flare up. It is crucial that you identify dampness in your home and ensure that the right treatment measures are taken. We have mentioned a couple of DIY ways for treating and preventing damp walls. If the damage is extensive, you can take the help of professionals as well.

Here’s to a clean, damp-free home, folks!

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