What Causes Damp Walls and What is the Solution?

–Passivhaus Weatherproof Masonry Protection & Brick Sealer Cream – Intelligent Membranes

As we come to the rainy spring season, many people are faced with the persistent problem of damp walls in their home and looking for a solution. Dampness can deteriorate a building faster, if left untreated, which is why knowing what causes damp walls is essential.

In this article we’ll go through the different causes of damp walls, the types of dampness and give you our modern solution to this common problem. So let’s get further into the topic of damp walls and what causes the issue!

What are the Different Types of Damp?

Before we get to the root of what causes damp walls in your home it’s important to understand that there are different types of damp. The three main types of dampness are rising damp, penetrating damp and condensation. Here is what causes each of them and what are the identifying factors of the different types of damp:

Rising Damp

Rising damp occurs when moisture from the ground travels up the walls through capillary action. What this means is that groundwater is essentially sucked up though the bricks.

You can generally identify rising damp by the damage it causes to the internal walls. Rising Damp creates noticeable tide marks that usually appear around halfway up the wall. In addition, as the moisture absorbed from the internal brickwork travels up it can cause wallpaper and plaster to start cracking or peeling. With this type of damp you will also notice decaying or rotting skirting or floorboards along the affected wall.

Penetrating Damp

Penetrating damp is caused by moisture moving from the exterior walls of a building to the interior ones through the brickwork.

It’s common to occur when weather conditions such as heavy rainfall impact the exterior of the building. Bricks and other building materials are porous, so they soak up rain and moisture from the air, saturating the wall with penetrating damp.

Depending on the exact source, signs of penetrating damp may vary. Some of the common identifiers include damp staining and localised patches that appear to grow in size. Penetrating damp can also cause damage to plaster and brickwork on the internal walls.

Condensation

Condensation is formed when the warm moist air in the room touches the cold internal wall. As the air cools down too fast it condenses back into water, creating damp patches over the wall. This type of damp is common in new builds, where more effort is put into keeping the heat inside the house than allowing the building to breathe.

Persistent problems with condensation can lead to damage on the internal walls as well as mould. If your walls are cold and wet to the touch then you might be having condensation issues. Other telltale signs of condensation is the presence of black mould on windowsills or walls as well as cracked paint.

What Causes Damp Walls?

So what are the common causes of damp walls? There are numerous reasons why you might be struggling with dampness in a house from lack of a damp proof membrane to problems with guttering. Here is what causes damp walls: 

Insufficient Damp Proofing

The most common cause of dampness in your internal walls is lack of a damp proof course or the insufficient presence of one.

A damp proof course is a waterproof layer or membrane that stops water and moisture from travelling up your walls. Usually, a damp proof membrane is applied where the external wall meets the internal, as well as on floors and ceilings. This is done to stop rising damp from getting through from the ground and penetrating damp from entering via the brickwork.

Our Passive Purple range is designed to help damp proof any internal and external walls of a building by creating a breathable membrane. This stops moisture from getting in, while allowing your building to breathe.

Plumbing Issues

Plumbing is another factor that can play a role in your problem with damp walls. You might be thinking that a small drip isn’t significant, however, even the tiniest leakage can cause big damage. Regular and concentrated water leaks in the same spot can result in intense dampness in this area of the wall.

To avoid this type of problem make sure your water pipes and seals are all up to standard. You might also want to think about installing a liquid waterproof membrane on the internal bathroom walls that are shared with other areas of the house.

Gutter Leakages

Leaking gutters can also lead to damp walls. In particular, they can lead to penetrating dampness through the internal wall.

When your gutter starts leaking, there are generally a couple ways the water can drain. The first one is by running down the external wall. The second way is by splattering on the ground and any other surface below.

To avoid moisture penetrating through the brickwork, you can install an external damp proofing membrane. This will stop water from entering the internal walls from the outside.

Cracked Rendering

Cement rendering that is usually used on the exterior walls of a building will often develop cracks over time.

When this happens, it allows moisture to get into the wall through the cracks. And since the water entering the wall has no way of getting out, it results in damp patches on the internal walls. As water sits inside the walls, it also prevents condensation from inside the house from escaping, deepening the issue further. 

A durable exterior render primer like ours can help in preventing the cement rendering from cracking. This will also help protect your building from the effects of moisture. 

Replaced Solid Floors

When replacing solid floors, especially in old buildings, you have to be very careful about trapping moisture. Normally, excess moisture from the lower floor will harmlessly pass up into the air.

If you replace the old solid floors with modern ones, however, you can trap the moisture under the floor. With no means for the moisture to escape, it’s forced to travel into the adjoined walls. This will lead to moisture sitting in the base of the walls causing damp patches

Installing a floor damp proof membrane before putting down your new flooring will prevent the accumulation of moisture and save you from potential damp issues.

Cold Spots

Another common reason for damp internal walls, as we have already mentioned, is condensation. If your internal wall is cold, the warm air trying to escape condensed into water when it comes into contact with the wall. 

In such situations, it’s essential to identify what’s causing cold spots on a wall. Sometimes it can be a problem as simple as cracks in the external mortar. Other reasons can be air leakages through poorly sealed windows or doors or poorly ventilated chimney breast, if you have a fireplace. 

The solution to this is ensuring your building is airtight, but still breathable enough for moisture to pass through. Our PassivHaus certified products can help achieve just that. 

Prevent Damp Walls in Your Home With Intelligent Membranes

If you’re looking for the ideal solution to your problem with damp walls, then our liquid DMP range is what you need. Our liquid damp proof wall membranes can be used to help by protecting your walls from the effects of penetrating moisture and rising damp.

Our products are designed with modern construction techniques, featuring sustainable technology to offer an innovative solution to an age-old problem. Shop our full range of damp proof solutions including our Poseidon – Liquid Applied Waterproof Membrane, External Waterproof Membrane and more.

If you have any questions don’t hesitate to get in touch with our team!