In France, humidity is a big problem. In Île-de-France, for example, 25% of the dwellings are affected. If it is not treated, moisture can be a saltpeter on the walls.
The saltpeter (also called stone salt) is a hell for the interior. The whitish deposit under which he presents attacks the walls, takes off the plaster and rots the wood. To get rid of it, you have to show a method. Here’s how to treat the saltpeter.
Dry up the hair lifts
The saltpeter is made up of potassium salt that comes from the water in the groundwater. It is therefore because of the hair lifts that the stone salt manages to get back into the walls. Before you do a surface treatment, you need to dry the walls.
To do this, you have 2 options:
Inject hydrophobic resin into the wall
Make a watertight barrier between the floor and the wall by making a pre-bleed
The second method is much more expensive than the first, but it gives better results. However, it creates a lot of work. This option should be preferred only if you plan to do large jobs.
Investing in a good quality VMC
Once your wall is dry, invest in high-performance ventilation. What for? Because the saltpeter only settles in humid atmospheres in which air does not circulate.
You have several choices depending on your budget:
VMC simple flux: Extracts the stale air from the humid parts and releases it outward via the ventilation ducts. The new air naturally enters through aerations located in the living rooms (so it is not aspirated)
VMC dual Flux: functions as a single-flow VMC, but also has the function of vacuuming and reheating the outside air to inject it into the building.
VMR (Distributed mechanical ventilation): Same operating principle as VMC, but air is expelled via individual aerators.
VMI (Reverse mechanical Ventilation): infuses hot air into the rooms.
Make the stains of saltpeter disappear
Once the two previous steps have been completed, you can proceed with the removal of the saltpeter. To do this, you remove all contaminated coatings.
Wait until the wall is completely dry to install a new coating. Depending on the humidity level, it may take several months.
To remove the saltpeter, here is the procedure:
Rub the wall with a brush
Seal the holes with a coating
Pass a special coating against the saltpeter
Go to finishing (tapestry, painting…)
Is it possible to treat the saltpeter yourself?
To overcome the saltpeter, you will have to get rid of the hair lifts. If you don’t, white deposits will come back sooner or later. The injection of resin is not complicated to make from the technical point of view. But in practice it is much more complicated. As a study has shown, the choice of resin in relation to masonry is decisive.
Plus, how are you going to replace your own ventilation system? How will you choose the most suitable type of VMC? You will have understood: to treat the saltpeter, it is better to be helped by a professional of the sector. He will be able to offer you a winning strategy against moisture.
Comments
Post a Comment