How do you effectively treat capillary rise?

Capillary rise or rising damp is a physical phenomenon caused by water rising from the ground into the walls of houses. In the long term,the build-up of damp in walls can cause serious damage and weaken the structure. As soon as damp is detected, homeowners need to be made aware of the problem and informed of possible solutions. We can help you to diagnose rising damp problems more accurately and offer your customers the right solutions.

How can you recognise damp in a wall and when should you consider treatment?

Moisture is common in the following cases:

• In old houses built before 1970 (the date on which the waterproofing strip was made compulsory in new buildings),
• In buildings close to a water source,
• In houses without a crawl space, where there is no waterproof barrier,
• In new buildings, when the waterproofing is ineffective or non-existent.

Moisture absorbed by the floor will spread and tend to rise up the wall to evaporate. As the water evaporates, it leaves characteristic marks on the surface of the wall:

• Humidity is present inside the house.
• The materials at the bottom of the walls have deteriorated (skirting boards, stones, etc.) over a distance of 0.80 to 1.50 m from the ground.
• Moss grows at the bottom of the walls outside the house.
•  Mouldand sometimes fungi are present in the house
• Wallpaper or other plaster on the wall is deteriorating, blistering and staining.
• White patches and halos, also known as efflorescence or saltpetre, are visible. These are mineral salts that rise up and are deposited on the wall. Unfortunately, this saltpetre is hygroscopic, so any drying out of the wall is blocked.

It’s important to carry out a more detailed visual diagnosis first, to prevent any damp from occurring in the first place, and then, if necessary, to carry out a more technical diagnosis and consider more drastic solutions to combat capillary rise.

What are the solutions for treating capillary rise?

There are several methods available today for treating capillary rise and dry out walls :

1. Electroosmosis

Electroosmosis can be passive, active or phoresis. This technique reverses the direction of water flow, pushing the water downwards and inverting the natural polarity of the soil. If the action of the electro-osmosis is interrupted in any way, the system will no longer function and humidity will reappear very quickly. Making this choice requires a great deal ofcare and attention. On the other hand, following a comparative study, the French Building Federation did not consider electro-osmosis to be the most effective solution for combating capillary rise as the most effective solution against capillary rise.

2. Outdoor drainage

Some soils (e.g. clay) are more hydrophobic than others, such as sandy soil. Installing drains all around the house helps to evacuate water that tends to stagnate in the foundations and rise by capillary action. This technique alone does not eliminate water, but it does reduce the risk of rising damp.

3. Resin injection to dry out walls

A liquid resin or gel is injected under pressure into the structure of the materials. When the resin comes into contact with water, it crystallises. This makes the materials hydrophobic and modifies the capillarity coefficient of the substrate, creating a continuous, impenetrable barrier that is permanently watertight. Thanks to its low surface tension, the product spreads throughout the capillary network of the substrate materials, whatever the level of humidity. Depending on the condition and the situation, the injection pressure will be adjusted. Following a comparative analysis, the French Building Federation has concluded that resin injection is the most effective solution for drying out walls following capillary rise.

Drying out your walls not only guarantees their solidity, it also protects the health of the house’s inhabitants. Treating capillary rise correctly is essential for a healthy home.

XILIX ® BLOCKAQUA as a treatment against capillary rise

Groupe Berkem offers XILIX ® BLOCKAQUA , a range of reliable and effective injection products, as well as comprehensive support from technical advisers to help you diagnose and implement solutions.

The XILIX ® BLOCKAQUA CREAM solution ensures perfect, even distribution of the resin in the mass of the materials and in the joints.