Dampness and leaks caused by capillary action are perhaps the most problematic to treat, both for the difficulty to detect the origin of the leak as for the work to be carried out to correct the problem. They are also the most dangerous because they can affect the foundations and supporting structures of a house, deteriorating it if no action is taken. 

Leaks by capillarity mainly arise from two sources: rainwater leaks and groundwater leaks. Let’s now consider the leaks caused by groundwater, also called capillary growth. 

When the water comes from underground it is very likely that you will not be able to tackle the real source of the problem, as maybe the water table is too near the foundation, the site is very permeable, there is an underground stream nearby, and so on. In this case the only option left is to protect the house against dampness.

The effects of this type of damp usually occur in ground floors or basements, on the bottom of the exterior walls. The white powder spots that can reach heights over a meter are very characteristic. This efflorescence is saltpeter that emerges due to the dampness. In more severe cases the coating of the wall may swell and get detached.

To start with, you can consider applying waterproof mortar on the damp wall, on the inside. This would remove the damp spot. Another option, as mentioned in the article devoted to leaks of rain water, is to build a counterwall, well insulated and located about 10 centimeters from the original wall, without letting it come into contact with the main wall at any point. The problem here is that you will lose space in the room, basement or garage. In any case bear in mind that any of these methods will only hide the damp spots from sight, but the leaks will not disappear.

To avoid problems with dampness, buildings must have what is known as a capillary cut, an unbroken gasket or underground joint, made with a mixture of water-repellent materials on which the rest of the building stands. With this system any possible damp in the ground will not rise along the walls. 

Also, it is a good idea to carry out drainage works laying drain pipes, perforated or porous, which will redirect the water away from the house. But if there is dampness it means that, obviously, your house has been built without these systems. When the problem is serious, conditioning work can be quite complicated and it is better to resort to professionals.

Trying to create a capillary cut in a building that does not have one is no easy task. It is possible to gradually cut the base of the wall to introduce water-repellent coatings, always with extreme care to avoid weakening the wall inadvertently and making it fall. Another option is to establish a chemical barrier. A series of holes in the base of the wall are made, through which waterproof materials are injected under pressure. When they solidify they will cover the cracks and pores.

Another method available is called electro-osmosis. The electro-osmosis bases its operation on the movement of water molecules induced by an electromagnetic field through a porous medium. The installer will place electrodes on the base of the walls and a touchdown on the ground. The electromagnetic field generated will make the water go down little by little instead of up: the walls will slowly dry.

By Webmaster on [15/04/2010 15:36]
Category : Building works and alterations
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