Can you paint over mould?

It is not advisable to paint or coat directly over mould. When mould is not completely killed and removed first, it remains active beneath the paint layer and will become visible again over time. This not only produces a poor finish but also shortens the lifespan of the paint. We recommend always tackling mould thoroughly first, then painting afterwards. Always check the maintenance and application instructions from both the paint and substrate manufacturer beforehand.

HG solutions for mould on walls and painted surfaces

To effectively remove mould on walls and painted surfaces, we offer targeted solutions specifically developed and officially approved for this application. Using the HG products below, mould can be safely and effectively tackled, provided you follow the instructions for use:

• HG mould remover foam spray: This mould cleaner features a unique foam formula with a less penetrating smell. It targets mould more precisely and reduces splashing. The foam stays in place longer for better and longer-lasting action. It is suitable for tiled and rendered walls, including marble and other natural stone, as well as grout in bathrooms, showers, toilets, kitchens, cellars, basements, saunas, swimming pools, garages and sheds. The product has a bleaching effect; if in doubt, test first on an inconspicuous area.
• HG mould spray: This product destroys mould on damp areas immediately, both indoors and outdoors, without scrubbing or rubbing. It is suitable for tiled walls, including marble, grout and render in bathrooms, showers, toilets, kitchens, cellars, basements, saunas, swimming pools, garages and sheds. It bleaches grey and black mouldy areas.

For both products: do not remove the mould beforehand. Spray from a distance of 3 to 5 cm. For stubborn soiling, repeat the treatment after 30 minutes and leave for a further 30 minutes. Then clean the surface with water and a sponge. Always check the substrate manufacturer's maintenance instructions beforehand. For more information on treating mould on walls, see our detailed guide.

Solutions to prevent mould on walls and painted surfaces

Household remedies and general cleaning products are regularly mentioned online for removing mould from walls and paint. We strongly advise against using these. Only officially approved products guarantee safe and effective mould removal. Unapproved products do not address the root cause of mould, offer no guarantee of results and can damage the substrate. Always check the substrate manufacturer's maintenance instructions before applying anything.

• Use only officially approved products specifically designed for removing mould from walls and painted surfaces.
• Always read the maintenance and cleaning instructions from the substrate manufacturer beforehand.
• Ensure adequate ventilation during and after treating mouldy areas.
• Treat the entire affected surface to minimise the return of visible mould.

General or non-specific solutions usually do not address the cause of mould growth. For lasting results, it is important to pay attention not only to cleaning, but also to conditions such as moisture levels and ventilation in the room.

Causes of mould growth on walls and ceilings

Mould growth on walls and ceilings usually results from a combination of environmental factors. The most common causes are:

• Moisture problems: Leaks, rising damp or prolonged high humidity create ideal conditions for mould growth.
• Poor insulation: Cold surfaces can cause condensation, making it easier for mould to develop.
• Inadequate ventilation: Especially in bathrooms, kitchens and other damp rooms, a lack of ventilation can lead to moisture build-up.
• Poor air circulation: Stagnant air increases the risk of moisture accumulating on walls and ceilings.

To prevent mould growth, it is important to address moisture problems structurally, ensure good ventilation and provide adequate insulation. Never paint or coat directly over mould. Instead, remove it carefully first and address the root cause before applying a new paint layer. This approach ensures that your paint job will last longer and that the mould problem is truly resolved rather than simply hidden.