Frequently asked questions about moisture and mould

Mould often has a furry appearance and can be various colours. It can appear as small spots or cover entire surfaces. Sometimes discolouration remains after wiping. Mould often smells musty or damp. If you suspect mould, also check behind furniture, skirting boards and under carpets.

All mould can be dangerous because it releases spores into the air. These can irritate the respiratory tract. Mould in living spaces should always be removed.

Remove the mould and eliminate the cause of the moisture.

Yes, you can remove small areas of mould yourself. Use 70-80% alcohol (e.g. ethanol or isopropanol). Be aware that alcohol is flammable.

Mould should be removed dust-free. Wipe with a damp cloth and household cleaner or vacuum with a vacuum cleaner with a HEPA filter. Alcohol can help with small areas of mould, but not with large areas. Vinegar is not suitable as mould will grow back on it.

Lightly mouldy furniture can be cleaned. Furniture with smooth surfaces can be wiped down. Porous materials (cupboard backs), upholstered furniture and mattresses usually need to be disposed of. Heavily mouldy materials should also be disposed of.

Wash clothes at the highest temperature if they have been stored in a mouldy room. Clothes that are heavily mouldy should be disposed of.

Wipe down the tiles and grout after showering. Ventilate the bathroom well to remove moisture. Keep the bathroom door closed and dry towels outside.

No. Mould must first be removed and the source of moisture eliminated. Anti-mould paint is not recommended.

Not normally. Once the mould has been removed and the cause eliminated, disinfection is not necessary. Alcohol can be used for small areas of mould.

The Federal Environment Agency advises against this. These agents often contain harmful substances that can irritate the respiratory tract.

Experts such as building surveyors can help. You can find them through the Chamber of Industry and Commerce or the Chamber of Crafts, for example.

There is no standard certificate. Ask the company about their experience.

Open the windows fully several times a day to let fresh air in. The heating should be turned off while ventilating. Cellars and basement rooms are best ventilated at night or early in the morning in summer.

Depending on the home and how it is used, it is necessary to ventilate two to five times a day. If you see moisture on the windows, ventilate immediately.

Yes. Cold air is usually drier than warm air, even when it is raining or foggy. Just make sure that no rain comes in.

You can measure the humidity with a hygrometer. In winter, it should be below 55% and in summer below 60%.

A log helps to identify humidity problems. Measure the humidity and temperature regularly and note down the values. This can be useful for consultation purposes.

Hygrometers are available at DIY stores and electrical shops. You can also borrow one from your local consumer advice centre.

In winter, you should make sure you heat and ventilate your home properly. Furniture should not be placed directly against exterior walls.

Living areas should be heated to around 20 degrees Celsius. At night, the temperature should not fall below 16 degrees. Heaters should never be turned off completely in winter.

For legal questions, please contact a tenancy law advisor or a solicitor. You can clarify structural issues with a construction company or an expert.

This is a legal question. Please consult a solicitor or tenancy law advice service.

Measurements are possible, but often not necessary. It is important to remove the mould and remedy the cause. If you would like to have measurements taken, ask the measurement institute whether it complies with the current guidelines.

Quick tests are not recommended as they do not provide reliable results.