A damp basement is a common issue many homeowners face at some point. You might notice a musty smell, damp patches forming on the walls, or even small puddles on the floor. At Aquaplan, we hear these kinds of stories from customers every day. A damp basement isn’t just unpleasant – it can also cause structural damage and pose health risks if left untreated. The good news? There are highly effective solutions, and you can apply them yourself as a DIYer.

Our product experts are here to guide you with expert advice and high-quality solutions. We’ll explain the leading causes of moisture problems in basements, the potential consequences, and – most importantly – how to fix and prevent the problem.

The basement is often the lowest point in a house, making it vulnerable to moisture. In addition, it often doesn’t have proper ventilation or the protection needed to prevent moisture problems. This is why it’s so important to address moisture problems in time before they get worse.

Some common causes of a damp basement:

• High water table: Groundwater pressure is one of the leading causes of a damp basement. When the water table is high, groundwater can seep through the basement walls. Especially if the foundation of the house is not well protected from water. This often happens during heavy rainfall or in areas with high water tables – often close to rivers or lakes.
• Porosity of building materials: Brick foundations (often in older homes) have a porosity of 35%, which means they easily absorb moisture and are more susceptible to moisture problems. Concrete has a lower porosity (10%) but can still let water through and cause damage if the walls are not treated properly.
• Rising damp: This mainly occurs in interior basement walls. Moisture rises from below through the walls because there are no damp-proof courses. It damages the plaster, paint and other materials on the walls.
• Leaks: Leaks from broken pipes can also cause temporary moisture problems. This is often an unexpected cause that can be quickly resolved by repairing the pipe. 
• Lack of ventilation: This allows moisture to build up, leading to mould and a musty smell.

If you notice damp in your basement, don’t ignore the problem. It can spread quickly and eventually lead to mould, structural damage and even health problems. Our product experts Guido and Kevin always recommend taking immediate action when moisture is detected in the basement. The sooner you address it, the easier (and more cost-effective) it will be to solve the problem.

We are often asked: ‘How bad is a little moisture in the basement?’ The answer depends on the severity of the problem. A small damp patch may not be a disaster, but the damage can accumulate if you ignore the signs. A damp basement can lead to:

1. Structural damage
   Salt efflorescence on walls, crumbling plaster, peeling paint and concrete rot can be the result of long-term moisture problems. This can affect the stability of the basement wall and even cause foundation problems, which can compromise the integrity of your entire house.
2. Energy loss
   When basement walls are damp, they extract heat from the room. This can lead to higher energy consumption because your heater has to work harder to keep the temperature constant. And this will be reflected in your energy bill. 

Health risks
Damp environments are ideal for mould growth. This can harm your health, especially if you are exposed to it for a long time. Mould can result in breathing problems or allergies. Storing food or beverages in your damp basement can also cause health problems. The musty smell associated with damp and mould has a negative impact on the air quality in your home.

A damp basement is an annoying but solvable problem. With the right diagnosis and the proper products, you can make your basement completely watertight again – all by yourself. There’s no need to hire an expensive professional. Our product experts Guido and Kevin recommend several efficient DIY solutions, depending on the situation.

In existing basements, it’s usually necessary to tackle moisture problems from the inside. There are two solutions for this:

• Basement Protect Cement: This is a waterproof cement coating that you apply directly to the walls. Note: only suitable for bare concrete blocks or cemented walls. Not suitable for painted walls. After 24 hours of drying time, it provides a durable barrier against moisture infiltration.
• Basement Protect Epoxy: A very strong and elastic waterproof coating applied in two layers, with 8 hours of drying time between each layer. It’s suitable for almost any substrate, including painted walls, red brick and even the floor. It provides an extra tough, hard-wearing barrier against water pressure.

These products are ideal for DIYers as they’re easy to apply. Our clients often find this solution practical because there’s no need to work on the outside of exterior walls. Want to know how to use Basement Protect Epoxy? Guido will show you in this video tutorial!

If you are dealing with rising damp in an internal basement wall, you can use injection methods to protect the affected wall. Our Wall Protect Inject Cream Kit or Wall Protect Inject Liquid are ideal for this type of problem. They are injected directly into the free-standing walls of your basement and create a physical barrier that prevents damp from rising.

Sealing along the foundations is one of the best ways to prevent groundwater infiltration. Products like Foundation Protect Regular (substrate must be dry) and Foundation Protect Expert (substrate can be damp) are applied to materials that come into contact with groundwater. The strong protective layer forms a waterproof barrier, even underground. These solutions are extremely effective but require a bit more work and preparation, such as excavating the basement’s exterior walls.

Want to get to work and tackle the damp in your basement? Be sure to read our step-by-step plan first. Good luck!

While it’s important to address moisture problems in time, preventing them altogether is even better. Here are some preventive measures you can take to ensure your basement stays dry.

• Correct choice of materials: Choose waterproof building materials when you renovate or build your basement. This helps to keep moisture out from the start.
• Exterior protection: Ensure proper drainage around your basement and apply exterior protection.
• Good ventilation: Make sure your basement is well-ventilated to prevent mould and musty odours.

Drainage systems: Install drainage systems that help drain excess water during heavy rainfall.

The effectiveness depends on the water pressure in your basement. On average, treatment remains effective for 3 to 10 years. In the event of high water pressure, it’s wise to reapply a layer of Basement Protect Epoxy or Basement Protect Cement after a few years.