A basement should be dry. But if it smells musty, if there is a damp spot on a wall or if there are the first signs of mold growth, this can have various causes. In any case, it is advisable to look for the cause.
If you have moisture in the basement, you should get to the bottom of it quickly. Because the cause can be banal, but it can also be serious. And if moisture persists in walls or floors, a home can suffer fundamental damage. The testing organization DEKRA points this out.
If it smells musty in the basement, if there is a damp spot on a wall or if there are the first signs of mold growth, there can be simple causes. For example, a lot of humid air from a laundry room or simply not enough ventilation.
To find out, you should ventilate regularly for a while. It is best to open windows and doors wide for a few minutes several times on dry, cold winter days, if possible with a draft. One exception: When cross-ventilating across several rooms, the door to a laundry room is best left closed.
DEKRA also advises moving the cupboards in the basement away from the wall. This allows the air to circulate behind it as well, which reduces the risk of mold in these areas.
If the moisture cannot be removed with such simple means, homeowners should contact a specialist, according to Dekra. Because there can also be a serious cause behind damp basement walls. Complex and expensive measures are then usually necessary.
According to the Association of Private Builders, for example, water or heating pipes in the wall can be damaged. A defective vertical seal can also be to blame for moisture damage. This is because it actually prevents moisture from penetrating the building from the outside through the walls.
For example, if an old black bitumen coating has decomposed after 30 to 40 years, it must be renewed. For this, the house must be excavated from the outside all around.
The horizontal sealing can also be defective or – as is often the case with old buildings – not exist at all. It normally prevents moisture from the soil rising up into the house through fine pores. It can be retrofitted, both from the inside and from the outside.
