Mould on walls, and why it keeps coming back
Cleaning it off is the easy part, and it is not the part that matters. What the government's own guidance says about removing mould, about bleach, and about who is really to blame.
By The Damp GuyLast updated
The short version
You can take mould off a hard surface in twenty minutes. A proprietary mould cleaner, a mask, gloves and goggles, the door shut and the window open. Then the official guidance tells you the part nobody prints on a product label: simply removing surface mould will not prevent the damp and mould from reappearing. Mould is the visible end of a moisture problem, and the smell is the end you get first. So the cleaning is housekeeping. The fix is whatever puts water into that wall. Two things worth knowing before you start: the guidance says mould and mildew products should be used in preference to bleach, and it is blunt that blaming mould on how a household lives is not a reasonable answer.
How to take it off, properly, once
This is the method in the government guidance, and the size limit that comes with it.
The guidance draws its line by area. Most tenants, it says, could reasonably be expected to remove condensation and very small amounts of mould. Larger areas of mould should only be addressed by qualified professionals. That line works for an owner-occupier too. A patch behind the wardrobe is a Saturday morning, though what it has done to the clothes in front of it is a separate job. A wall of it is not, and neither is a roof space furred with it, where the surface you would be cleaning is the structure itself, and nor is a bathroom ceiling, a large area worked overhead with a cold void usually sitting straight above it.
Photograph it before you clean, and note where it is. The guidance asks for this, to help identify the source. It is also the only record you keep once you wipe the evidence off. If you rent, it is the only record your landlord gets of what it looked like.
Then take it off. Mould comes off hard surfaces with an appropriate cleaning product, and the surface should be left to dry completely. Wear a mask, gloves and goggles to keep the spores and the cleaning product off you. Shut the door, which helps stop spores spreading to other rooms. Leave the window open during the clean-up and after it.
Anything absorbent is a different story. Soft furnishings and ceiling tiles may have to be thrown away if they become mouldy. You cannot clean mould out of something porous the way you wipe it off plaster.
Bleach is the standard advice, and it is not the official advice
Ask around and someone will tell you to use bleach. It is on the forums, it is in half the articles, and it is already under your sink.
The guidance goes the other way, in one short sentence: mould and mildew products should be used in preference to bleach, for health and safety reasons. Read that carefully. It is a preference on health and safety grounds, not a claim that bleach kills nothing. Follow it for the same reason you would anywhere else in the house.
Any proprietary mould and mildew product, used as its label says, is what the guidance describes, and there is one named further down this page. Nothing on this site earns a commission, that link included, and I am not going to point you at a bottle I have not read the label of. What that one is, what is in it and what it will not do are all on the card.
It is not your lifestyle, and the government has said so
If someone has told you the mould is down to drying washing indoors, read this paragraph.
The wording is unusually direct for official guidance: "We are absolutely clear that it is totally unreasonable to blame damp and mould in the home on 'lifestyle choices'." It then makes the obvious point. Cooking, bathing, washing and doing laundry are unavoidable, and every one of them puts moisture into the air.
The causes it names are the building: deficiencies in the fabric, inadequate ventilation, inadequate heating and poor energy efficiency. Not the occupant.
That matters, because "lifestyle" is the standard reply. It is what a household hears when it reports mould, and it dumps a building problem on the person living in it. You do not have to accept it. You can point at the guidance that says so.
You are not alone in this either. Estimates of the number of homes in England with damp and mould range from 4% to 27% of homes, which is between 962,000 and 6.5 million households. That range is enormous. Quoting it as a range is the honest move, rather than picking whichever number suits the argument.
What the guidance says about health
This site cannot give you medical advice and does not try. The government's own guidance is blunt, and it belongs to the Ministry of Housing, Communities and Local Government, the Department of Health and Social Care and the UK Health Security Agency: "The respiratory effects of damp and mould can cause serious illness and, in the most severe cases, death."
That sentence deserves more room than a page about cleaning can give it. What the harm actually is, who it lands hardest on, and what the poisoning claims do and do not rest on is a page of its own. Symptoms are a question for a GP, not for a website. If you rent, the mould is a question for your landlord.
If you rent from a council or housing association, you have a clock
Awaab's Law phase 1 has been in force since 27 October 2025, and it sets deadlines you can hold a landlord to.
| What has to happen | Deadline | Counted from |
|---|---|---|
| Investigate a potential hazard | 10 working days | Becoming aware of it |
| Give you the findings in writing | 3 working days | The investigation concluding |
| Complete works on a significant damp and mould hazard | 5 working days | The hazard being identified |
| Investigate and make safe an emergency hazard | 24 hours | Reasonable grounds to believe it exists |
If your landlord cannot meet those timescales, it must offer you and your household suitable alternative accommodation, at no cost to you.
Check whether it covers you, because it is narrower than people assume. It applies to social housing tenancies: local authority landlords and registered providers such as housing associations. It does not apply to shared ownership, homeless accommodation, supported accommodation or licences in social housing. It does not apply to the private rented sector at all. A private tenant has other routes, just not this clock.
It is also widening. From October 2026 the same regime extends to excess cold and excess heat, falls, structural collapse and explosions, fire and electrical hazards, and domestic and personal hygiene and food safety. From October 2027 it covers all other significant hazards apart from those arising from overcrowding.
One more line helps you whoever your landlord is: an inspection of the home is preferred over an assessment based on photos. So if someone is assessing your mould by photograph, that is not what the guidance asks for. After treatment, landlords should allow at least 6 weeks before revisiting. That is what a realistic check-back looks like, rather than being told it is sorted on the day.
Then find what is feeding it
Once it is off the wall you are back to the only question that matters. Where is the moisture coming from? Mould does not need a soaking wall. It needs a surface that stays humid, and the condensation page covers the threshold that decides whether it grows. If your pattern follows the rain instead of the cold, you are looking at water getting in from outside, which is a defect with a location. And if someone reaches for a meter to prove a point, be careful what that number actually means.
The mould came back last time because the moisture never left.
Taking the stain off
The guidance above asks for a proprietary mould and mildew product used as its label says, in preference to reaching for household bleach. This is one of those, and the foam is the part that matters on a wall: it stays where you put it instead of running off it.
What I’d use
Mould remover, foam spray
Scrubb Mould & Mildew Cleaner (1 litre)
A bleach-based foaming spray sold for taking off the staining that mould leaves on a wall.
The guidance this site quotes asks for a proprietary mould and mildew product used as its label says, in preference to reaching for household bleach, and this is one of those rather than a bottle of bleach with a new name. The foam is the practical part: it clings to a vertical surface instead of running straight down it, which is what gives a cleaner time to work on a wall.
- Size
- 1 litre
- Active
- Sodium hypochlorite
- Form
- Foam spray
- Guarantee
- 1 year
Watch out for
- It removes the stain. It does nothing about what is feeding the mould.
- Warning: causes skin irritation and serious eye irritation.
- It is bleach-based, so keep it off metal fittings and anything coloured.
- Classed as hazardous, so it is not delivered to offshore addresses.
That link earns me nothing. It is not an affiliate link, no brand pays for a mention here, and I get the same whether you buy this or ignore it. It is on the page because it is what the job takes.
No brand pays for a mention here, and nothing on this page earns me a commission. The card above links out to a shop, and I get the same whether you buy or ignore it. The link is there because finding the thing is the boring half of acting on advice, which is also why the watch-outs sit on the same card as the reasons to buy.
About this resource
The removal method, the bleach preference, the lifestyle-choices wording and the prevalence range all come from "Understanding and addressing the health risks of damp and mould in the home", published by the Ministry of Housing, Communities and Local Government with the Department of Health and Social Care and the UK Health Security Agency, updated 1 April 2026. It is free to read. The Awaab's Law timescales are phase 1 of the regime that came into force on 27 October 2025.
One mould remover is named, further down, and it earns me nothing. Nothing here is medical advice. The health passages are the government's, quoted as theirs, and a symptom is a question for a GP. This site does not survey, treat or quote for work.
Common questions
Is bleach or vinegar better for killing black mould?
The government guidance answers half of that and ignores the other half. It says mould and mildew products should be used in preference to bleach, for health and safety reasons. Nothing read for this page supports a claim about vinegar either way, so none is made. The larger point is that the argument is over the wrong step. Whatever comes off the wall, the guidance is explicit that simply removing surface mould will not prevent the damp and mould from reappearing.
Does painting over mould stop it?
No. Painting over it does less than cleaning it off, and cleaning it off is already not the part that decides whether it comes back. The paint sits on a surface that is still humid enough to grow mould, so it grows again through or under the new coat. If the plaster is soft or the paper is lifting, you are looking at something that needs taking off rather than covering up.
Do I have to throw everything away that has mould on it?
Not the hard surfaces. Mould comes off those with an appropriate cleaning product, and the surface is then left to dry completely. Absorbent things are the problem. The guidance says soft furnishings and ceiling tiles may have to be thrown away if they become mouldy, because you cannot clean mould out of something porous the way you wipe it off plaster.
What time of year is worst for mould?
The cold months, and not because cold itself grows anything. Winter is when surfaces run coldest against the room, which is what pushes the humidity at those surfaces up, and it is also when windows stay shut and washing comes indoors to dry. The two changes stack. That is also why mould appears to go away in summer and comes back in the same corner every autumn, having never actually been dealt with.
Should I wipe mould off the walls?
Yes, if the patch is small, and photograph it first. The guidance asks for a photograph and a note of where it is, to help identify the source, and once you have wiped it that record is all you have. Wear a mask, gloves and goggles, shut the door and leave the window open during the clean-up and after it. Larger areas of mould should only be addressed by qualified professionals.