How to Stop Damp On Concrete Floors?

While having damp walls means that you are susceptible to damp problems, issues of damp occurring on concrete floors is also a common problem that you might need to be aware of.

This occurs when the damp proof membrane has not been installed before the floor has been laid or it has failed for some reason. It is a real issue when moisture is too high and then the water rising above the layer of concrete.

Below, we will explain how damp can affect your concrete floors and what damp proofing methods would be used to treat the problem.

Accredited to

Nic Glover

Branch Manager and Waterproofing Design Specialist CSRT CSSW
North East

Damp affecting Concrete Floors

Floors can easily suffer from moisture ingress otherwise known as penetrating damp. Damp in concrete floors are much more difficult to treat than having damp walls. The reason for this is that concrete is a very porous material meaning that water can rise through capillaries and therefore lead the property to suffer from having damp floors.

There are simple steps that can be carried out if the floors are affected by damp above the ground such as external defects (for example pipes and gutters). To fix this problem would require isolating the source of the moisture problem and then taking the necessary steps to help the floor dry out.

Fixing the Damp Proof Membrane

If your property is suffering from rising damp which then rises through to the surface of the concrete then this is a more complicated procedure to fix. This is less common in new buildings as damp-proof membranes are required at the initial construction phase to prevent rising damp.

The plastic membranes are installed onto sand blinding before the application of the concrete. If this damp proofing method is installed correctly then this will provide protection against groundwater rising damp up from the concrete.

This unfortunately, in most cases, did not happen in older buildings where there was no damp proof membrane in place and the concrete floors would, therefore, be vulnerable to damp problems.

Traditionally the method of treating dampness in floors was that the whole floor would need to be replaced. This was not only a time-consuming process but a costly form of getting rid of the damp problem.

There are two methods of damp proofing concrete floors which can be carried out without having to replace the floors. This can either be the use of a damp proof coating which is applied on the surface of the concrete or a membrane on top of the concrete.

Damp Proof Floor Coating

A damp proof coating will be applied onto the concrete floor with a roller or brush. Preparation will be key to this solution working effectively.

When a technician carries out this practice the surface must be clean and dry before applying the coating. If there is any dust or dirt left on the surface this will impact how efficient the coating is.

damp proof floor coating

Plastic Damp Proof Membrane

The second option is to use a damp proofing membrane on top of the existing concrete surface. This is more than often an easier and quicker option than using a damp proof coating.

damp proof membrane on concrete floor

This is due to the fact the membrane can be applied onto the damp surfaces so there is little surface preparation that needs to be made. However, it is important to note that a separate floor will need to be added on top of the membrane.

Damp in Basement Concrete Floors

Basements are prone to dampness and flooding so waterproofing solutions would be used to rectify this problem. Instead of one waterproofing solution, there would be a combination of waterproofing treatments used.

A waterproofing design specialist would be required to examine the basement and put in place a plan to treat the damp basement problem.

Basements and cellars suffer regularly suffer from water ingress so a cavity drain system would need to be used to manage the moisture ingress instead of a damp proof membrane.

A cavity drainage system would use the combination of a cavity wall membrane, perimeter drainage channel and a sump and pump system. This waterproofing system is effective by channeling the water away from the basement before it reaches the concrete floor.

Contacting A Professional for Treating Damp in Concrete Floors

If the property is suffering from damp on concrete floors either above or below ground then you should always contact a professional.

Timberwise has a number of damp specialists who have treated a variety of damp related issues in properties across the UK. You can get in touch by booking a survey online or calling us on 0800 288 8660.