Do you also suffer from rising damp? There's a good chance you're having problems with the water barrier. The term water barrier is an impermeable layer applied in brick walls at 20 to 30 centimetres. The aim is to prevent moisture from rising and damaging the entire wall.

Luc Lambrecht

The water will then disperse into the wall and the salts in it will crystallize.

But this layer must be intact over the entire length of the walls, otherwise it loses its function. The water will then disperse into the wall and the salts it contains will crystallize, resulting in white spots.

Moss can also form. The infestation goes over the entire width of the wall and can go over a large length.

Installing a new water barrier

The question, in the case of rising damp, is in the first instance whether there is a water barrier in your walls. If not, it is best to install one. This can be done in two ways. The first is to cover the wall. This involves cutting into the wall a few centimetres above the floor and inserting a moisture barrier into the cut. In order not to endanger the stability of your house, this has to be done very carefully, meter by meter. It is a time-consuming, labour-intensive and expensive job. A second option is to inject a damp-proofing agent, often based on silicone, into the wall. If there is already a water barrier, it must be investigated why it does not work
properly. Sometimes the plaster comes under the water barrier and has to be removed and replaced by a water-repellent ("hydrophobic") product. Sometimes it is also the case that the ground surface outside the house has increased over the years, as a result of which the water barrier is too low and water can still penetrate into the walls. In that case, the water-repellent layer must be placed higher.

There was rising damp in three of our houses. In two of them there may have been a flood barrier, but only 1 of the 9 experts who came by suggested to take a closer look at it and possibly repair it.