What can be done preventively against mould
Airing in case of humidity in rooms
The best orientation for ventilation is provided by a hygrometer. Especially in old buildings (until about 1980) during the winter (below +5 °C) when exceeding approx. 50 relative humidity must be ventilated. Rule of thumb: Cold air is dry air, warm air is rather humid air. It follows that airing is “more successful” in cold air, which can be early in the morning, in the evening, at night. This applies not only to living and working spaces, but above all to cellars.
Heat all rooms
Room temperatures should never fall permanently below 18 °c. Close doors to less heated rooms. Cold rooms are at risk for mold. Complete cooling and heating increases heating costs.
Absence during the day is not a problem
It is best to ventilate thoroughly before leaving the apartment. Close the windows and do not allow rooms to cool below 18 °c. Please do not leave the windows tilted – even risk of burglary.
Furniture away from exterior walls
5 to 10 cm distance from the wall allow air circulation; prevent the mould! Exterior walls are very cold, especially in old buildings. This is not a tree construction, but due to the construction age/material. The worse the thermal protection of the outer wall, the cooler and wetter the living environment, the greater the distance between a piece of furniture and the wall. In extreme cases up to 20 cm, so that the air can circulate.