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. 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. A wall of it is not.
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.
You will find no product recommendation on this page. Nothing on this site earns a commission at the moment, and I will not point you at a bottle I have not looked into properly. Any proprietary mould and mildew product, used as its label says, is what the guidance describes.
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. What follows belongs to the Ministry of Housing, Communities and Local Government, the Department of Health and Social Care and the UK Health Security Agency. It is reported here as theirs.
Their words: "The respiratory effects of damp and mould can cause serious illness and, in the most severe cases, death." Most people meet the substances damp and mould produce by breathing them in, so the airways and lungs take the brunt. The guidance also names eye irritation, eczema, skin rashes and fungal infections. It says some people exposed to damp and mould might experience poor mental health as a result of living with it.
It names the groups at higher risk: people with pre-existing respiratory conditions, people with weakened immune systems, pregnant women, children, older people, and people who are bedbound or housebound.
If someone in your house is in one of those groups, this stops being a decorating problem. Take symptoms to a GP. Take the mould to your landlord if you rent.
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.
About this resource
The removal method, the bleach preference, the health section, 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.
No product is named and no mould remover is recommended. 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.
What are the 10 warning signs of mould toxicity?
There is no list of ten in the UK guidance, and no such list is offered here. What the guidance does say is that the respiratory effects of damp and mould can cause serious illness and, in the most severe cases, death, and that most people come into contact with it by breathing it in, so the airways and lungs take the brunt. It also names eye irritation, eczema, skin rashes and fungal infections. Symptoms are a question for a GP, not for a website.
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.