A Simple Guide to Basement Tanking and Waterproofing

Basements are susceptible to damp. This is because water and moisture can easily travel through the ground and into your walls. If you’ve got a basement that you want to convert into living or storage space, you might need to look into basement tanking and waterproofing.

Keep reading to find out everything you need to about tanking or waterproofing your basement.

Why is basement tanking and waterproofing necessary?

If you want to start using your basement, it’s really important that you protect it from damp and flooding. Even if you only want to use it for storage, anything from flooding to a low-level damp problem can damage your things.

Plus, damp and flooding problems can build up over time and can easily cause health problems and structural damage.

There are two main ways to waterproof your basement. You can either tank it using a waterproof material or install a cavity drain membrane system.

Basement tanking

Basement tanking involves coating the inside of your basement walls to stop moisture from getting in. This is usually done with a cement-based material that won’t let water travel through it.

Basement tanking can be quite labour intensive, as you’ll need to remove any existing plaster from the walls. You also might need to repoint the wall and apply salt-neutralising products before you coat on the tanking product. This is because water can build up and put pressure on your basement walls, so they need to be in good condition to withstand it.

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Tanking tends to be the best way to deal with low-level damp problems in your basement. You don’t need to tank the whole of your basement if it doesn’t need it, so it’s a good way to treat small areas.

Cavity drain membranes

An alternative to tanking is installing a cavity drain membrane system. This involves fitting a plastic membrane to your basement walls and floor to prevent water from getting in. Your installer will leave a cavity between the membrane and your basement walls, which will let any water that enters your basement run down to a larger cavity under the floor. The water will then run out through a drainage system, often with the help of a pump.

Fitting a cavity drain membrane tends to be the best way to deal with flooding problems or severe damp. This is because the system is equipped to deal with large amounts of water. If you try to deal with these kinds of problems using basement tanking, it might lead to structural damage and leaking.

If you’ve got a damp problem and think you might need basement tanking or waterproofing, it’s a good idea to speak to a professional. They’ll be able to give you advice and carry out any work that you need doing.

If you need help finding a damp proofing professional in your area, click ‘Start my project’ and complete our online form. We’ll put you in touch with up to 4 reputable contractors.


Approx. £700 - £2,000 per square metre

Depending on the size and condition of the basement

Installation time

Up to around 3 weeks

Depending on the type of treatment and the size and condition of the basement

Advantages and disadvantages
  • Help to prevent damp and flooding
  • Can stop existing problems from spreading or escalating
  • Can tackle both flooding and damp problems