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Can You Paint Over Mould?
Updated 4 November 2026. Reviewed by Michael Young, Head Contractor at Advanced Damp (CSSW and FODCS).
Key Takeaways
- You can paint over mould, but it will come back. Paint does not kill mould or stop the moisture feeding it.
- Clean the mould off properly, let the surface dry, then use a stain block primer and a good anti mould paint.
- Anti mould paint slows regrowth but does not fix condensation, leaks or rising damp.
- Large areas, recurring mould or mould on damp, crumbling plaster point to a problem that needs diagnosing.
The short answer: painting over mould hides it for a few weeks at best. The spores are still alive under the paint and the moisture that let them grow is still there, so the black spots return, often through the new paint. The right order is to find and fix the cause, clean the mould off, let the wall dry, and only then repaint with the right products.
Why mould grows on walls and ceilings
Mould needs moisture, a surface to grow on and time. In most homes the moisture comes from condensation: warm, moist air from cooking, showers, drying washing and breathing settles on cold walls, window reveals and ceiling corners. It can also come from a leak or defect letting water in from outside, or from rising damp at the base of ground floor walls.
Mould on cold external walls, behind furniture and around windows, worse in winter, is usually condensation. Mould on a patch that is wet to the touch, stained or crumbling usually means water is getting into the wall itself. Our guide to the difference between damp and mould explains more.
How to remove mould safely before painting
For small areas of surface mould, roughly the size of a door or less, you can usually clean it yourself:
- Wear gloves, eye protection and a mask, and open a window.
- Do not dry brush or sand the mould, as this spreads spores into the air.
- Wipe the area with a fungicidal mould wash, following the product instructions, and leave it to work.
- Wipe clean with a damp cloth and dispose of cloths in a sealed bag.
- Clean nearby soft furnishings and check behind furniture for hidden growth.
- Let the surface dry completely before doing anything else.
Do not mix cleaning products, especially bleach with other cleaners. If anyone in the home has asthma, allergies or a respiratory condition, avoid cleaning mould yourself and speak to your GP if you are worried about health effects. Our guides on whether black mould is dangerous and how damp affects health have more information.
When not to tackle mould yourself
- The mould covers a large area or several rooms.
- It keeps coming back after cleaning.
- The plaster underneath is damp, soft, stained or crumbling.
- There is a musty smell but you cannot see where it is coming from.
- You live in a rented property, where the landlord should investigate the cause.
In these cases cleaning and painting will only buy time. Professional mould removal alongside a diagnosis of the cause is the better route.
How to repaint a wall after mould
- Dry first: make sure the wall is fully dry. Painting a damp surface traps moisture and the paint will fail.
- Stain block primer: mould often leaves dark staining that bleeds through ordinary emulsion. A stain blocking primer seals it in.
- Anti mould paint: use a paint containing a fungicide in kitchens, bathrooms and other areas prone to condensation.
- Two coats: apply as directed, with good ventilation while it dries.
Does anti mould paint work?
Anti mould paint contains fungicides that slow regrowth on the paint surface, and it is a sensible finish in bathrooms and kitchens. What it cannot do is stop condensation forming, warm a cold wall or stop water coming in. If the conditions that caused the mould are still there, mould will eventually return, sometimes on furniture, curtains and window frames instead of the painted wall.
Fixing the cause so mould does not come back
- Extraction: effective extractor fans in kitchens and bathrooms, run during and after use.
- Ventilation: open trickle vents, keep air bricks clear, and consider continuous ventilation such as positive input ventilation. See our ventilation service.
- Heating: keep rooms at a steady, moderate temperature rather than heating them in short bursts.
- Moisture sources: dry washing outside or in a ventilated room, and put lids on pans.
- Cold spots: treat cold bridges, uninsulated walls and poorly insulated ceilings.
- Repairs: fix any leaks, gutters, pointing or render defects letting water into the wall.
Our guide to stopping condensation on windows has more practical tips.
When to book a damp survey
If mould keeps returning, affects several rooms, or appears with damp or damaged plaster, the cause needs identifying before money is spent on redecorating. Our surveyors check moisture levels, humidity and surface temperatures, inspect the outside of the building and explain the cause in a written report. Book a damp survey online or see our damp surveys in London.
Frequently asked questions
Can you paint over mould?
You can, but it will come back. Paint does not kill mould or remove the moisture that lets it grow. Clean it off, fix the cause, let the wall dry and then repaint with a stain block primer and anti mould paint.
Why does mould come back after painting?
Paint does not kill mould spores or fix the moisture that feeds them. Unless the condensation or damp causing the mould is solved, it will grow back through or on top of the new paint.
Does anti mould paint work?
Anti mould paints contain fungicides that slow regrowth, and they help in bathrooms and kitchens. They are a useful finish once the cause is fixed, not a substitute for fixing it.
How should I prepare a mouldy wall before painting?
Clean the mould off with a fungicidal wash without dry brushing, let the wall dry completely, then apply a stain blocking primer before your top coats.
Should I use bleach on mould?
Bleach can lighten mould stains on hard, non porous surfaces but is less effective on porous plaster and must never be mixed with other cleaners. A purpose made fungicidal mould wash is usually a better choice.
Who is responsible for mould in a rented home?
Landlords are responsible for repairs and for dealing with damp and mould caused by disrepair. Tenants should report mould promptly in writing so the cause can be investigated.
Reviewed by Michael Young, Head Contractor at Advanced Damp (CSSW and FODCS). Last reviewed November 2026.
Related Case Studies
Our recent work includes first floor flat, Brixton SW9; flat entrance hall, Marlow SL7 and house, Surbiton KT5. Each case study sets out what the survey found and how the problem was fixed.
First floor flat, Brixton SW9
Thermal imaging found cold external walls behind recurring black mould. Isotherm insulation and electrical works followed.
Read the case study →
Flat entrance hall, Marlow SL7
Mould from thermal bridging at the door and intermittent heating, not rising damp. Mould wash and fillet seal.
Read the case study →
House, Surbiton KT5
No active rising damp. Blocked air bricks replaced and extraction proposed to deal with condensation.
Read the case study →
Sam Fitzgerald is the founder of Advanced Damp and a working damp and structural waterproofing surveyor diagnosing and treating moisture problems in residential and commercial properties across London and the South East. He is FODCS certified (a Federation of Damp Certified Surveyor) and a member of the Federation of Damp. His hands-on work covers rising damp, penetrating damp, condensation, basement waterproofing to BS 8102, and thermal imaging surveys, and he has personally completed over 400 damp surveys across properties of every type and age. Everything he writes draws directly from jobs he has carried out. He does not write about treatments, products or causes he has not dealt with first-hand in the field.
