Black mould removal
The black, spotty mould on bathroom ceilings, bedroom corners and the silicone round the bath is almost always caused by condensation. It can be cleaned off in an afternoon. Keeping it off means dealing with the moisture that feeds it.
We're a free matching service. Your enquiry goes to one independent specialist who covers your postcode, not a list of firms. They quote you, and the work is between you and them.
What black mould looks like, and what it tells you
Clusters of small black or dark green dots, sometimes merging into patches, on a surface that's often damp. It grows where moist air meets something cold and stays there: the ceiling above the shower, the top corners of a bedroom, the inside of window frames, the back of a wardrobe against an outside wall.
That pattern is a clue in itself. Mould in spots, high up and in corners, points to condensation. A single brown-edged patch that spreads after rain points to water getting in from outside, which is a penetrating damp problem first and a mould problem second.
How a specialist deals with it
- Cleans and treats the affected surfaces with a fungicide suited to them.
- Cuts out and replaces mouldy silicone and sealant.
- Strips mouldy wallpaper and, if needed, treats or replaces plaster or plasterboard.
- Checks the extractor fan: does it work, is it strong enough, where does it actually vent, and does it run on after the light goes off?
- Recommends fixes for the cause, such as a new fan, trickle vents, a positive input ventilation unit or insulation on a cold wall. More on the condensation and ventilation page.
Room by room
Bathrooms. Ceiling, grout and silicone. Nearly always fixed by extraction: a humidity-controlled fan ducted properly outside, left to run after showers.
Bedrooms. Corners, behind furniture and around windows. People breathe out a surprising amount of moisture overnight, and a bedroom kept cool with the door shut is ideal for mould. Background ventilation and a little heat help most.
Kitchens. Above cupboards and behind appliances. A cooker hood that recirculates rather than venting outside does little for moisture.
What it usually costs
| Job | Typical range | Source |
|---|---|---|
| A single wall | £150–£200 | MyJobQuote |
| Per room | £200–£400 | Checkatrade |
| Half a house | £400–£1,600 | Checkatrade |
| Whole property | £725–£1,100 | MyJobQuote |
| Replacing a bathroom extractor fan like for like | £80–£150 | MyJobQuote |
Sources: MyJobQuote mould removal costs (updated 11 September 2026), Checkatrade mould removal cost guide (last updated June 2026) and MyJobQuote extractor fan costs (updated 15 September 2026). None of them prices black mould separately; it's costed as mould removal.
A bathroom job that's mostly cleaning, resealing and a better fan sits at the bottom of these ranges. Mould through several rooms, or plasterboard that needs replacing, moves it up.
Facts, dates and prices on this page were last checked on 29 October 2026.
Common questions
Is black mould more dangerous than other mould?
"Black mould" is an everyday name for several dark-coloured moulds, not one species. Government guidance on damp, mould and health treats damp and mould in general as the risk, and says it should be dealt with promptly whatever its colour.
Why does black mould keep coming back on my bathroom ceiling?
Because the ceiling is the coldest surface the steam reaches, and it stays wet after every shower. A fan that's too weak, switched off too soon or venting into the loft is the usual culprit. Cleaning helps for a while; better extraction stops it.
Can I paint over black mould?
Not until it's been cleaned and treated, and the surface is dry. Paint over live mould and it grows straight through. Anti-mould paint helps afterwards but won't fix the cause.
Do I need to replace the silicone around the bath?
If the black is inside the silicone rather than on top of it, cleaning won't shift it. Cutting it out and resealing is usually quick and cheap.
I rent and there's black mould in the bedroom. What should I do?
Report it to your landlord in writing, with photos. The tenants' guide sets out what happens next and who can help if they don't act.
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