Waterproofing the cellar

The basement is quite often the underdog in a home. Maintenance, such as waterproofing your basement, is often enough put on the back burner. Not so smart, because moisture in the basement should not be underestimated. It is unhealthy because of the mould that can develop. It affects your belongings and creates a musty smell. Moreover, it can also cause your energy bills to go up. Moisture in the basement should therefore be prevented and, where necessary, combated by means of basement sealing.

How does moisture actually get into the basement, how do you recognise it? What are the consequences and why should you do something about it (or have something done about it)? In this article, we answer these questions.

What does it cost to waterproof your basement?

Answering this question is not so easy. Because the problem of moisture in your basement can occur in many ways. Every situation is unique. In addition, the level of costs is determined by several factors. For example, what technique is used to combat the damp, what products are used, how big is the area of the basement and what is the severity of the problem?


Let’s take a look at a few common problems and see what basement waterproofing will cost approximately. Average prices include labour, materials and VAT.

• With little moisture damage. Coating walls of a small basement up to 9m2. £500
• For rising damp in the walls. Wall injection per 10 linear metres.£1,000
• For a serious moisture problem. Basement sealing up to 16m2. £ 2,000

How does your basement waterproofing actually work?”

Stiff lining is a relatively simple a commonly used method of waterproofing a basement. This is done by smearing a waterproof paste on the walls and floor With this you thus make your walls-, and also concrete waterproof. First, all cracks are repaired and then the room is made dust-free. By smearing the walls and floors several times with the waterproof paste, you can be sure that the basement will be completely waterproof again.

Smooth waterproofing is also a good way to waterproof your basement. This method gets its name from the flexible foil that is attached to the wall. A new wall is then bricked up against the foil layer. Especially when the moisture nuisance is very high, this method of moisture control is usually chosen. Basement sealing is a fairly major intervention but it guarantees a completely watertight solution to the moisture problem.

Coating involves applying a layer of moisture-resistant paint to the wall. This should ensure that moisture no longer soaks into the walls. Coating is a relatively cheap way of basement waterproofing that is especially effective when the moisture problem is small. If you have painted a wall before, it is perfectly possible to tackle this yourself.

Injecting, however, is better left to the professional. Injection injects a damp-proof gel into your walls under high pressure. This prevents rising damp. This method is often used because rising damp is one of the most common problems in the basements of the damp and water-rich Netherlands.

How does damp actually get into the basement?

Since a large part of our country lies below sea level, groundwater is never far away. There is not much you can do about the state of groundwater. Groundwater tends to move up through the floor or walls. Even concrete walls have to be waterproofed. Not for nothing is this moisture problem number one in the Netherlands. About one in three houses has or may have to deal with rising damp. Under older houses in particular, there is often no water barrier to ensure that the water is absorbed and thus has little chance of penetrating the walls, so basement sealing is extra important here.

What else plays a role in a watertight basement?

Although the chance of suffering from rising damp is a lot lower when there is a water barrier at ground level, other factors also play a role. Of course, the quality of the floors and walls also matter whether or not you should have your basement waterproofed. Should these turn out to be porous then you will automatically bring the moisture problem into your basement. Poor ventilation of your home is not good either because it causes higher humidity. By the way, did you know that the amount of salt in the cement also plays a role? Salt actually attracts water and stores it.

How do you recognise a basement that is not watertight?

It is best to detect moisture problems as soon as possible.

• If, for example, you see white salt spots on your wall, then you should sound the alarm.
• This is just as true if you see loose or cracked skirting boards, peeling paint or wood rot.
• This is nothing compared to when you find traces of mould. It is then really high time to take immediate action.
• Signs such as high humidity and a musty smell should also be taken seriously and indicate that your basement is not completely watertight.

What are the consequences of a damp basement?

When basement sealing has not been done, it can have unpleasant consequences. Walls containing a lot of moisture become increasingly porous and can crumble. In some cases, this means the wall has to be replaced in its entirety. Moisture in the basement also affects the rest of your home. For example, it has a negative impact on the temperature in the house. So you will have to heat more. Moreover, the musty smell can migrate upstairs, making your home smell far from fresh. A troublesome moisture problem is mould. Not only ugly to look at, they can also be a health hazard. For instance, you can get breathing problems.

Why should I waterproof my basement?

Summarising briefly, here are the main reasons:

• Moisture creates an unhealthy living environment. Excessive humidity is an extra burden especially for asthma and rheumatism patients. In addition, moulds are also a health hazard. You’d better get rid of them as soon as possible.
• Moisture increases the likelihood of pests.
• Because of a damp cellar, you have to heat much more. Waterproofing your basement means lower energy bills.
• Moisture in walls and floors leads to a worse state of the house. This negatively affects its value.
• Food and items you keep in the basement suffer from moisture. You yourself are the victim when you use the cellar as a hobby or sleeping space.