Dark, often black spots in the corner of a room, behind a cupboard, or around a window frame: black mold is one of the most common moisture problems in Dutch homes. Read on to learn how it forms, what the potential consequences are, and which steps actually help.
What exactly is black mold?
Mold is a type of fungus that grows as soon as there is enough moisture, a food source (dust, wallpaper, wood, paint), and a little warmth present. The black color comes from the spores the mold spreads. These spores are present everywhere in the air, both indoors and outdoors, but they only develop into a visible colony when a surface remains damp for a long period.
Where does it occur most?
- Corners of exterior walls, especially near thermal bridges
- Behind cupboards and furniture placed against an exterior wall
- Around window frames where condensation accumulates
- Bathrooms and basements with poor ventilation
- Places where laundry is dried indoors without sufficient air circulation
What are the risks?
Aside from the aesthetic aspect (nobody wants black spots on their wall), mold can also affect the air quality in the home. Many people notice that they are more prone to irritated noses, throats, or eyes in a damp, moldy room. Long-term exposure can contribute to respiratory complaints, especially in those already sensitive to them. Furthermore, in the long term, mold also damages the building structure: masonry joints, woodwork, and plasterwork can weaken.
How do you structurally tackle black mold?
- Find the source of the moisture. Is it condensation, a thermal bridge, a leak, or simply insufficient ventilation? Without addressing that source, the mold will return, even after cleaning.
- Ventilate structurally, daily and also in winter, so that humid air can escape.
- Keep furniture slightly away from exterior walls so that air can circulate.
- Lower the humidity in rooms that are structurally too damp.
- Insulate thermal bridges where possible so that the wall surface cools down less quickly.
Dehumidifier as part of the solution
A dehumidifier does not take the place of ventilating or repairing leaks, but it is a valuable addition in rooms where humidity remains structurally too high, such as basements or poorly ventilated bedrooms. Our recommendation is the Dynter AirPure DH251 dehumidifier: by keeping humidity structurally below the critical threshold, you give mold much less chance of returning. Large areas (more than approximately one square meter) should preferably be handled by a professional.