Those black or greenish patches that appear in corners, behind furniture or around windows don't just make the place look bad: they can also affect your health and ruin the paintwork. Knowing how to remove mould from walls in good time stops it spreading and stops the problem coming back over and over. In this guide we explain why mould appears on walls, how to get rid of it without damaging the wall and, above all, how to prevent it from returning.
Why mould appears on walls
Mould is a fungus that needs damp and poor ventilation to grow. That's why it turns up most often in bathrooms, kitchens, poorly lit bedrooms and on walls that face outside. Understanding the cause is the first step to getting rid of it for good.
- Condensation from temperature differences between indoors and outdoors.
- Lack of ventilation: the moisture has nowhere to go and settles on the walls.
- Water leaks or rising damp coming up from the floor.
- Drying laundry indoors without opening the windows.
How to remove mould from walls step by step
Before you start, protect yourself: put on gloves and a mask, and open the windows to air the room while you work. Mould spores spread easily and are best not breathed in. Then follow these steps:
- Air the room and protect it. Cover the floor and any nearby furniture with plastic sheeting.
- Apply the product. Spray the area with whichever solution you've chosen and leave it to work for ten to fifteen minutes.
- Scrub gently. Use a bristle brush or a scourer, without pressing too hard so you don't lift the paint.
- Rinse and dry very thoroughly. Wipe away the residue with a clean cloth and dry the wall completely; any damp left behind will feed the mould.
How to remove mould with hydrogen peroxide and other remedies
You don't need to spend much to get results. These are the most effective products for removing mould from walls:
- Hydrogen peroxide: apply it directly to the patch, let it work and scrub. It's gentler than bleach and disinfects well.
- White vinegar: spray it undiluted, leave it a few minutes and wipe. Ideal for small, surface patches.
- Bicarbonate of soda: mix it with a little water to make a paste and use it on the most ingrained areas.
- Diluted bleach: very effective on hard-wearing surfaces, but use it carefully and with the room aired.
One important warning: never mix bleach with vinegar or with ammonia, as that produces toxic fumes. Choose a single product per clean and always ventilate the room.
Mould in the bathroom and behind furniture
There are spots in the house where mould nearly always appears and which are worth checking regularly. The bathroom is the most common: the tile grout, the sealant around the shower screen and the ceiling collect steam every day. In those cases, apply the product straight onto the grout, let it work and scrub with a small brush; if the sealant is badly damaged, the best thing is to strip it out and reseal.
Behind wardrobes, headboards and sofas pushed against the wall, mould also forms because the air doesn't circulate. Check those corners now and then, pull them a few centimetres away from the wall and, if you see patches, clean them as soon as possible so they don't spread to the rest of the room.
How to prevent mould at home
Removing mould is all well and good, but what really makes the difference is stopping it coming back. To prevent mould at home, a few simple habits are enough:
- Air the house daily, even if it's only ten minutes, especially the bathroom and the kitchen.
- Use the extractor fan when you shower or cook, or open the window.
- Pull furniture a few centimetres away from external walls so the air can circulate.
- Keep humidity in check with a dehumidifier or with moisture absorbers if your home is prone to damp.
- Dry out any leak or drip as soon as you can.
Having a good dehumidifier to hand, moisture absorbers for the wardrobes or a thermo-hygrometer to keep an eye on humidity helps enormously to keep walls healthy. At Velia Select you'll find products for the home and for damp control that make the job easier.
When to call a professional
Most mould patches can be dealt with at home, but there are signs that point to a bigger problem. If the mould covers a large area, comes back within weeks no matter how often you clean it, or comes with blistering paint and a persistent damp smell, there's probably a leak or a structural issue. In those cases it's worth having a professional look into the source of the damp before you spend any more on cleaning.
In summary
Now you know how to remove mould from walls and, most importantly, how to keep it from coming back: clear the patches with hydrogen peroxide or vinegar, dry the area very thoroughly and look after the ventilation and humidity in your home. With a bit of persistence and a few products you'll have clean walls, healthier air and a far more pleasant home.