Rare are the strictly paper-based wallpapers … They may contain foamed vinyl containing phthalates serving as plasticizer, various additives … Inks also can emit volatile organic compounds … As for paintings, choose as a priority a wallpaper rated A + for emissions into indoor air. And then, in addition to the wallpaper, we must consider the glue that we use: it can also emit volatile organic compounds. Even if it is to a lesser extent, also opt for an A + glue. “Paint or wallpaper, one cannot say that one is better than the other for the health; both will emit pollutants into the air, ”says Dr Squinazi.
There is another problem to think about: “While some wallpapers are meant to be cleaned, others are not. And they can, all the more so if they present reliefs on the surface, accumulate dust. Which is not necessarily favorable … In this respect, it is better to have a smooth paint that is easy to clean, ”continues the doctor. A healthy house is also a house that is easy to clean. You have to think about it for the choice of decoration.
What about other wall coverings?
Beware of wall fabrics which can emit VOCs due to the substances used to give them resistance. Furthermore, these fabrics have the drawback of being “absorbers” of VOC pollutants, which they can then release for long periods. Finally, they catch the dust. Avoid in the habitat of smokers and allergies!
As for the wood on the walls, in addition to the fact that it is treated and can emit VOCs, it can also accumulate dust, and even, in some cases, also be a pollutant absorber.
Finally, cork is porous: you can have problems with humidity, and therefore mold, in your home.
Saltpeter on the walls
Deposits of saltpeter on the walls show up as white crystals, fibers or white hairs, which can lead to entire plaque detachment.
Saltpeter is not a fungus. “This is a deposit made up of mineral salts at the bottom of the walls, when humidity has penetrated and the interior is poorly ventilated. Under these conditions, water infiltration which rises from the ground carries underground water through the walls. However, this water is loaded with bacteria and ammonia. In contact with the oxygen in the air and in the masonry, potassium nitrate is formed: it is saltpeter ”, explains Dr Squinazi. “During drying, the mineral salts present in the masonry are deprived of humidity and migrate to the surface of the wall to pump that of the ambient air. This causes the characteristic whitish deposits. “
“Saltpeter is a manifestation of the humidity of the walls of the building. It does not pose, in itself, health problems, but must draw attention to the humidity of the accommodation and its causes (water infiltration, poor ventilation, faulty ventilation, condensation on the coatings, etc.) », Continues the specialist.
No question of camouflaging this phenomenon as best they can! A professional should be called in to trace the source of humidity and consider the measures to be taken. A damp home is not very healthy: this can lead to the development of mold on the walls or ceilings, molds whose spores are released in theair are responsible for allergic respiratory diseases (rhinitis, asthma …).
How long to wait before reintegrating a refurbished part?
Scientific publications have shown, thanks to tests in an emission chamber that, when a part has just been repainted, significant pollution can last for several weeks, while most paints are dry to the touch in 30 minutes.
The minimum time to respect: it is not to reoccupy freshly painted rooms for at least three days, because the levels of VOC emissions are high. And during these three days, the windows must be kept wide open to regain an acceptable quality of the indoor air. This aeration divides, for example, by ten the concentration of glycol ethers. These precautions are all the more important to take for children, pregnant women, people with allergies, or those who are fragile on the respiratory level.
It is preferable to also respect this minimum time if you have lined the walls with wallpaper, laid a covering on the floor …
Now, if you wait longer than three days, that’s even better! A period of two weeks without occupying the renovated room, while ensuring good ventilation, would be ideal to ensure the evacuation of the maximum of pollutants.
