Mouldy walls with black stains? How to scrub them clean, plus tips to stop the mould coming back

In the rainy season or in very humid areas, what many homeowners can't escape is mould and black stains on the walls , which not only make the house look shabby but whose spores also harm the respiratory health of the people living there. This article shows you how to deal with mould stains properly and how to stop them coming back.

How to safely remove black stains and mould from walls

Mould needs to be cleaned carefully so the spores don't spread through the house. Follow these steps:

• Wear protective equipment: always wear a face mask, goggles and rubber gloves to avoid breathing in spores and cleaning chemicals
• Spray on mould remover: use a dedicated mould remover, or mix bleach with water, spray it on the black stains and leave for about 15-30 minutes to break down the mould
• Scrub clean: gently scrub off the black stains with a plastic-bristle brush; avoid wire brushes, which damage the wall surface and paint
• Wipe and let it dry completely: wipe off all residue with a cloth dipped in clean water, then turn on a fan or open the windows until the wall is completely dry

3 tips to keep mould from coming back

Once the mould is gone, the key is to fix the root cause so the black stains don't return:

• Improve ventilation: open windows for airflow, or install an exhaust fan in damp rooms such as bathrooms or kitchens
• Apply a waterproofing product: if the mould is caused by water seeping through the wall, coat the wall with waterproofing to block moisture from outside
• Use anti-mould house paint: if you repaint, choose a paint with additives that specifically inhibit mould and bacteria

Precautions and when to call a specialist

Safety precautions: If mould is growing near sockets, switches or wiring, never spray products or use water to wash it, as this can cause a short circuit — always switch off at the fuse box first. Also, if the mould is caused by a leaking pipe inside the wall, or there are large cracks in the wall structure, call a plumbing and structural specialist to inspect and fix the leak at its source before cleaning and repainting.