Damp and Mould: Who Has to Fix It, and When

Mould is a symptom of a moisture problem. What the law now requires of landlords, what changed in October 2025, and when cleaning is the wrong thing to buy.

Published by Jerimiah, owner of J&BROS Cleaning Last updated 6 September 2026 6 min read

In short

Mould is the visible result of a moisture problem, so cleaning it removes the symptom and not the cause. Government guidance for rented housing providers puts finding the underlying cause on the landlord. Since 27 October 2025 social landlords work to fixed timescales under Awaab's Law. Private renters are not covered by those timescales yet, but they can already take a landlord to court over a home that is not fit for human habitation.

Mould is not a cleaning problem that got out of hand. It is a moisture problem that became visible. That distinction matters because it decides who is supposed to fix it, and whether paying for a clean is a sensible purchase or an expensive way of hiding something.

The numbers say this is a rental problem

Where damp concentrates

The English Housing Survey puts the problem squarely in the rented sector, and East London has a great deal of private renting.

Tenure	Homes with a damp problem
Private rented	10%
Social rented	7%
Owner occupied	4%

What renters report is higher still

The gap between what surveyors see and what people report is wider again. Ask the households themselves and 46% of private renters report condensation, damp or mould at home, against 30% across every tenure. Some of that is seasonal, because a wall that is fine in July can run wet in January. Some of it is that people notice a bathroom ceiling long before a surveyor scores it as a hazard.

The commonest form is not a leak

6% of private rented homes

Most of it is condensation

gov.uk

Serious condensation runs ahead of penetrating damp at 4% and rising damp at 3%. Condensation is a temperature and ventilation story, not a leak.

What the law now expects

The duty sits with the landlord

Government guidance for rented housing providers is unambiguous about where the work sits.

Since 27 October 2025 social landlords in England also work to a clock. Significant damp and mould has to be investigated within 10 working days, the tenant has to be given a written summary of what the investigation found within 3 working days of it concluding, and the home has to be made safe within 5 working days of the same point. Emergency hazards carry a 24 hour requirement. The written summary is the one to ask for, because it is what you hold if nothing then happens.

Awaab’s Law has not reached private tenancies yet

If you rent privately, which most people reading this in Canary Wharf or Poplar will, those timescales do not apply to you yet. The Renters’ Rights Act is the mechanism that extends the duty to private tenancies, by implying terms into tenancy agreements, with the detail left to regulations that follow.

The route a private renter already has

Not being covered by Awaab’s Law is not the same as having no remedy, and this is the part most people reading about damp never get told.

The government’s own guide for tenants is direct about what that is worth. Where a rented home is not fit for human habitation, the tenant can bring the landlord before a court themselves, and the court has the power to order the repairs and to award compensation. Damp and mould growth is on the list of problems it covers. Anyone who signed a tenancy on or after 20 March 2019 could use it straight away, and after 20 March 2020 it reached secure, assured, statutory and private periodic tenancies whatever date they began.

Section 11 of the same Act runs alongside it, keeping the landlord responsible for repairing the structure and exterior, and for keeping the space and water heating in working order. A broken heater is not a lifestyle choice.

The local authority’s enforcement powers sit on top of all that, the same route that covers other whole building faults such as mice getting into East London flats. The gap left by Awaab’s Law is a gap in the timescales, not in the law.

Why it comes back three weeks later

Mould grows where a surface is cold enough and damp enough for long enough. Two of those three are properties of the building and the weather, not of your cleaning schedule.

Where the cold surface usually is

In an older converted flat around Limehouse or Whitechapel, the cold surface is usually a solid external wall, a window reveal, or the corner of a room behind a wardrobe where no air moves. In a newer block it is more often the glazing and the sealed envelope, which is covered in more detail in our guide to cleaning a new build flat.

Why wiping changes nothing

Either way, wiping the growth off changes none of it. You have removed the colony and left the conditions. Anyone who has cleaned the same bathroom ceiling twice in a winter already knows this.

What to do, in order

Photograph it, with a date. Before cleaning, before drying, before anything. Wide shot for the room, close shot for the growth.
Report it in writing. Email or the portal, not a phone call. You want a record of when the landlord knew.
Say where and when it appears. Behind the wardrobe, worst after showering, started in November. That is the information that points at a cause.
Check the ventilation actually runs. Hold a sheet of tissue to the extract grille. If it does not hold, the fan is not moving air, and that is a repair.
Then decide about cleaning. Once the cause is being dealt with, a clean finishes the job properly. Before that, it mostly buys time.

When we would tell you not to book us

If mould has come back on the same wall since the last time it was cleaned, a cleaner is not the right trade. Nothing we do changes the surface temperature of a wall or the amount of moisture the building is holding, and charging you to find that out again is not a service.

Where a clean does earn its place

Where a deep clean genuinely earns its place is after the cause is resolved, at the end of a tenancy once any dispute over the defect is documented, or on the surfaces where growth is a maintenance issue rather than a building fault, such as silicone seals and shower screens that never fully dry.

The honest summary

Then get the cause fixed, and clean afterwards, in that order. It is the cheaper sequence as well as the stronger one.

The numbers, and where they come from

Damp is worst in rentals: The English Housing Survey found 10% of private rented homes had a damp problem in 2024, against 7% of social rented and 4% of owner occupied homes.; Source
Most of it is condensation: Serious condensation affected 6% of private rented homes, more than penetrating damp or rising damp, which the same survey put at 4% and 3% of private rented homes.; Source
Reported far more than surveyed: 46% of private renting households said their home had problems with condensation, damp or mould, against 30% of households across all tenures.; Source
Landlords must find the cause: Government guidance for rented housing providers says landlords are responsible for identifying underlying causes such as structural problems or inadequate ventilation, and for finding lasting solutions.; Source
Fixed timescales in social housing: From 27 October 2025 social landlords must investigate significant damp and mould within 10 working days, write to the tenant within 3 working days of that, and undertake the safety work within 5 working days. Emergencies run to 24 hours.; Source
A private tenant's own legal route: Government guidance on the Homes (Fitness for Human Habitation) Act 2018 says that if a rented home is not fit for human habitation, tenants can take their landlord to court, and the court can order repairs and compensation.; Source
Damp is on the fitness list: Section 10 of the Landlord and Tenant Act 1985 lists freedom from damp among the matters that decide whether a dwelling is fit for human habitation, alongside repair and ventilation.; Source
Private renters are next, not yet: The Renters' Rights Act will extend Awaab's Law to privately rented homes by implying terms into tenancy agreements, with the timescales set out in later regulations.; Source

Common advice that is wrong

partly true
“Mould in a flat is the tenant's fault for not opening the windows.”

Tower Hamlets says the law makes a landlord fix damp from leaking pipes, rotten window frames, broken heaters or failed damp-proofing, and installing ventilation is the landlord's move too.

Ventilation genuinely matters and airing a flat is worth doing. What it cannot do is carry the whole load. Tower Hamlets sets the position out for private renters: the law says the landlord must fix damp caused by a leaking roof, gutter or cracked wall, leaking pipes, rotten window frames, broken heaters, or damp-proofing that is old or defective. It goes further. Even where the tenancy agreement is silent on conditions, the council says the landlord should improve the situation, and gives installing ventilation, improving insulation and providing a dehumidifier as its examples.

Source: towerhamlets.gov.uk
false
“Bleach kills mould permanently.”

Bleach lifts growth off tile or glass. That is surface work. Government guidance prefers mould and mildew products to bleach, and says removing surface mould will not stop it reappearing.

Bleach will take visible growth off a hard non-porous surface such as tile or glass, and that is a real result. The government's guidance for rented housing providers prefers mould and mildew products to bleach on health and safety grounds, and is blunt about what surface work achieves: simply removing surface mould will not prevent it reappearing. If a wall is cold enough and wet enough to grow mould once, it will grow mould again. On painted plaster or silicone you are bleaching the surface rather than treating what sits inside it.

Source: gov.uk
partly true
“Awaab's Law gives my landlord 24 hours to deal with mould.”

Emergency hazards are what the 24 hour clock covers. Significant damp and mould gets 10 working days to investigate and 5 more to make safe. So far that duty binds social landlords only.

The 24 hour clock is for emergency hazards. Significant damp and mould has its own sequence: investigate within 10 working days, issue the tenant a written summary of the findings within 3 working days of that investigation concluding, then complete the safety works within 5 working days of it concluding. Ask for that written summary, because it is the document that shows what the landlord found. The bigger point is scope: the duty applies to registered providers of social housing, and the extension to private tenancies comes through the Renters' Rights Act and the regulations after it.

Source: gov.uk
true but risky
“A deep clean will sort the mould before the flat is inspected.”

Photograph the growth, then report it in writing and keep a copy. The council's enforcement route runs on what an inspector can still see.

It will look sorted. Cleaning removes the staining and the smell, and for a viewing that is sometimes all anyone wants. The risk is what comes next. Tower Hamlets tells private renters to ask the landlord in writing and keep a copy. If nothing happens the council writes to the landlord and gives them three weeks, and it inspects only once you come back and tell it nothing was done. Then it can serve a formal notice, prosecute or fine. All of that turns on what is still there on the day. Photograph the growth before anyone cleans it.

Source: towerhamlets.gov.uk
false
“Private renters have no legal route until Awaab's Law is extended.”

The Homes (Fitness for Human Habitation) Act 2018 already lets a private tenant take a landlord to court over damp and mould, whatever Awaab's Law does next.

Two separate things get conflated. Awaab's Law sets the fixed timescales and currently binds social landlords. The Homes (Fitness for Human Habitation) Act 2018 is a different route and already reaches private tenancies. It lets a tenant sue over a home that is not fit for human habitation, and the court hearing the claim can make the landlord do the repairs and pay compensation. Damp and mould growth is on its list of problems. Anyone signing on or after 20 March 2019 could use it at once, and from 20 March 2020 it reached periodic tenancies whenever they began.

Source: gov.uk

What we see on the job

We get asked for mould cleans fairly often, and we will do them. We would rather tell you first when we think cleaning is the wrong thing to buy. If the same patch is back on the same wall a month after we cleaned it, spending again does not fix anything, and we will say so rather than sell you a repeat visit. We are a six person family team, not an agency, so you get the same people who saw the wall last time and can tell you honestly whether it has moved. If we miss something, we come back.

Common questions

Is mould in my flat my fault or my landlord's?

Usually it is a building problem that living in the flat makes visible. Government guidance for rented housing tells landlords to identify the underlying cause, such as a structural fault or inadequate ventilation, rather than attribute it to how the tenant lives. How you dry laundry and whether the extract fan works still matter, but they are rarely the whole story on their own.

How quickly does a landlord have to deal with damp and mould?

If you rent from a social landlord, significant damp and mould must be investigated within 10 working days, written up for you within 3 working days of that, and made safe within 5 working days of the investigation ending, with emergency hazards handled inside 24 hours. Private tenancies have no fixed clock yet, and the Renters' Rights Act is the route by which they will get one. A private tenant can still go to court now under the Homes (Fitness for Human Habitation) Act 2018.

Should I clean mould off before I report it?

Photograph it first, with a date. Clean it afterwards if you want to. The photograph is what makes the report credible later, and cleaning first removes the only evidence that the problem existed at the scale you are describing. Keep the written report too, because a phone call leaves no record of when the landlord was told.

Will a professional clean stop mould coming back?

Not by itself. Cleaning removes growth and staining from the surface. It does not change the temperature of the wall or the amount of moisture in the air, which are the two things that decided the mould would grow there. If the cause is untreated, expect it back within weeks. A clean is worth buying once the cause has actually been dealt with.

What actually reduces condensation in a modern flat?

Running the mechanical ventilation continuously rather than switching it off, using the boost setting during and after showers and cooking, keeping the filter clean, and drying laundry somewhere it can be extracted. In an airtight flat these do more than wiping the windows, because they change how much moisture stays in the air.

Does mould affect my deposit at the end of a tenancy?

It can, and this is where the photographs earn their keep. A deposit deduction has to reflect damage or a cleaning failure, not a defect in the building. Being able to show the growth was present, reported in writing and not fixed puts the conversation on much firmer ground than describing it from memory at checkout.

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