If you heat less because of the high energy costs and also ventilate less, you risk mold in your living space. It is a health hazard – and must be removed quickly and properly.

They are often the visible result of trying to save energy: mold stains in the home. Because those who heat little and ventilate less often create a comfortable climate for the mold fungi thanks to the high humidity in the living rooms.

However, the risk to health is not so obvious. Because there can long be more behind a few small stains on wallpaper, on joints and masonry. You can do this:

How do I remove minor mold stains?

Clean the surface. On smooth surfaces such as glass, metal, paintwork, ceramics and plastics, a cloth with a little household cleaner is usually sufficient, according to the North Rhine-Westphalia consumer advice center. Then throw the towel away. “You can also rub the surface with an alcohol-based disinfectant, i.e. with high-percentage alcohol of 70 or 80 percent,” says Stefan Betz, first chairman of the Federal Association for Mold Remediation. Joints and wallpaper should be removed and renewed. The consumer advice center recommends also wiping the wall with high-proof alcohol after detaching it.

You should protect yourself from the spores, i.e. wear gloves and a respiratory mask, as you know them from everyday life in a pandemic. For stains higher up, protective goggles are also useful to prevent harmful particles from getting into your eyes.

In order to keep the health risk low, Stefan Betz also advises: “If you remove wallpaper, you should always moisten it beforehand or just dab it with an alcohol solution. Then not much mold is released when you remove it.” Important: Ventilate the room well afterwards.

When is professional mold removal needed?

It is generally advised to only tackle areas that are no more than half a square meter in size. It doesn’t have to be a contiguous spot, says Stefan Betz. Even if there are several small spots of mold in an area of ??half a square meter in total, experts should be consulted.

The same applies to an infestation that is visually very noticeable, for example if fluff has formed on the spots. And even if you are unsure of the cause of the mold, the expert said, because: “An infestation does not necessarily have to be due to a ventilation fault or a room temperature that is too low. It can also arise because there is hidden water damage somewhere are”.

Where are mold spots most likely to form, which can be traced back to incorrect ventilation and heating?

“As a rule, the cold exterior components are then affected: the exterior walls and the corners where two exterior walls meet, or the area around the windows if they are poorly insulated or there are leaks there,” Betz enumerates. “If, on the other hand, there is mold on an interior wall, then it is more likely that there are other causes,” says the expert. About leaky pipes in the walls. If mold growth on interior walls is due to ventilation and heating, this is due to thermal bridges or the fact that the room is not heated at all.

Why is mold dangerous, especially for health?

Mold can cause allergic reactions and aggravate diseases, especially those of the respiratory tract. According to the North Rhine-Westphalia consumer advice center, people with health problems and those with a weakened immune system should avoid rooms with mold.

Mold also damages the structure of a building. In the worst case, this can lead to fungus-bearing wooden beams or the roof structure of a house being destroyed, making the building uninhabitable.

I removed the stains. Why do they keep coming back?

Superficial removal is not sufficient in all cases. Recurring mold spots indicate that the infestation had already penetrated into deeper layers and is still sitting there. “If I don’t adapt my behavior, then the mold behaves like weeds in the garden,” says Betz. “If I only remove the surface of the dandelion, its roots can sprout again.”

This can also be the case, for example, if the wallpaper only shows a few black dots on the surface. But if it has become detached from the substrate, according to Betz, this is a sign that moisture has already dissolved the remains of the paste, and that further action is therefore required. If one finds an even worse infestation behind a wallpaper than on its front, “then there is also more depth there,” says the expert. “Then you don’t just have to remove the wallpaper, maybe even part of the plaster.”

Will the problem go away with the onset of spring?

yes for now “As soon as the moisture stops, the mold can’t grow any further,” explains Betz. This also applies to an infestation in deeper layers. “So, of course, the problem will decrease or disappear altogether as the temperature increases over the course of the year. But what has developed up to that point is not gone, it is dormant, waiting for moisture to come in again at some point. Much like with a seed .” So that means: If you don’t act consistently, the problem will not just come back next winter. A mold infestation that is still present will then become even larger.

(This article was first published on Tuesday, January 31, 2023.)