Mould in a rental property is usually linked to excess moisture, but the cause can vary. Condensation is one possibility, while leaks, penetrating damp, poor ventilation or faults in the building can produce similar signs.
The 2024 to 2025 English Housing Survey found surveyor-assessed damp in 11% of private rented homes. In the same report, 47% of private renters said they had experienced condensation, damp or mould. These figures measure different things, but both show how common moisture problems can be in rented homes.
What happens next depends on what is causing the mould and how the problem has been handled so far.
Who Is Responsible for Mould in a Rental Property?
Responsibility for mould in a rental property depends on what is causing the moisture and what action is needed to remove it.
In England, government guidance says landlords should investigate damp and mould, address underlying causes and avoid treating surface cleaning as a complete solution. It also warns against blaming normal activities such as cooking, bathing or drying clothes without considering ventilation, heating and the condition of the property.
Condensation does not automatically make the tenant responsible. Poor insulation, cold surfaces, inadequate ventilation and ineffective heating can all contribute, sometimes alongside how the home is used.
| Problem | Who should investigate or act |
|---|---|
| Roof, gutter or plumbing leak | Usually the landlord |
| Cracked masonry or defective render | Landlord investigation |
| Broken extractor fan | Landlord repair |
| Inadequate ventilation | Landlord should assess provision |
| Cold wall or thermal bridging | Building condition should be assessed |
| Mould behind furniture | Airflow and wall temperature both need checking |
| Blocked vents or disabled extraction | Tenant behaviour may contribute |
| Unreported leak | Tenant delay may contribute to further damage |
| Cooking, showering or laundry | Normal moisture sources that require adequate ventilation and heating |
Symptoms alone cannot establish legal liability. The cause should be investigated before responsibility is assigned.
What Causes Mould in a Rented Property?
1. Condensation and Cold Surfaces
Condensation develops when warm indoor air meets a surface cold enough for moisture to settle on it. If those surfaces stay damp for long periods, mould can begin to grow around windows, in corners, behind furniture or on external walls.
Several conditions can make this more likely:
- Poor extraction in kitchens or bathrooms
- Limited airflow through the property
- Cold external walls and thermal bridges
- Inadequate insulation
- Heating that leaves some rooms or surfaces consistently cold
- Moisture from cooking, showering or drying clothes indoors
Those everyday activities are normal sources of indoor moisture. The more useful question is whether the property can deal with that moisture effectively. If ventilation is weak, surfaces remain cold or insulation is poor, condensation can persist even when the tenant is using the home reasonably.
2. Water Leaks and Penetrating Damp
Condensation is not the only moisture source that can lead to mould in a rented property. If growth is concentrated beneath a bathroom, around a ceiling or close to pipework, a plumbing leak may be contributing.
Mould that appears or worsens after heavy rain can point towards water entering through the building fabric. Possible sources include:
- Damaged roofing
- Leaking gutters
- Cracked masonry
- Defective render
- Poorly sealed windows
These problems are not always easy to trace from the visible patch alone. Moisture can travel through walls, ceilings or cavities before it appears indoors, so the point where mould develops may be some distance from the original source.
3. Low Level Damp
Low level damp can show up as patches near the floor, damaged plaster, peeling finishes or salt deposits on the wall. Those signs can point towards rising damp, but they should not be treated as proof on their own.
Other possible causes include:
- High external ground levels
- Plumbing leaks
- Rainwater entering through the wall
- Moisture moving through solid masonry
- Problems with the original construction
The pattern, height, and spread of the damp all matter. Before treatment begins, the source needs to be identified properly so the wrong remedy is not applied.
4. Hidden Mould
Mould can also develop where you cannot easily see it. Behind wardrobes, beneath wallpaper, under carpets and along cold wall surfaces, trapped moisture and restricted airflow can create suitable conditions for growth.
A persistent musty smell may be the first sign that hidden mould is present, especially if there is no obvious patch in the room.
If you suspect a larger concealed area, avoid pulling apart extensive sections of wallpaper, flooring or other affected material yourself. Disturbing heavily contaminated material can spread spores and debris through the room, so a controlled inspection is the safer next step.
What Should You Do If You Find Mould in a Rental Property?
1. Record the Problem Before Cleaning It
Before wiping the area down, take clear photos that show both the mould itself and where it sits in the room. A close view can capture the growth, while a wider photo gives useful context around windows, external walls, ceilings or nearby furniture.
It also helps to note when the problem first appeared and whether there is a pattern. Record if it gets worse after rain, if windows are regularly covered in condensation, or if the mould returns soon after cleaning.
If clothes, furniture or other belongings have been affected, photograph those too. Where possible, compare the current condition with your check-in inventory or earlier tenancy photos to see whether any damp or staining was already present.
2. Report the Mould to Your Landlord or Letting Agent
Once you have documented the problem, report it promptly to your landlord or letting agent. Always put repair reports in writing because it creates a clear record if further action becomes necessary.
Your message should state:
- Which room and area are affected
- When the mould first appeared
- Whether you have noticed a leak, water staining or another possible defect
- Whether the affected area is spreading or becoming more severe
Save the original report and any replies. If an inspection or repair visit is arranged, record the date and what work was proposed or completed. A clear communication trail can become important if the problem remains unresolved.
3. Allow Access for Inspection and Repairs
Once the issue has been reported, the next step is usually an inspection. Your landlord may need access to check the affected room, trace moisture and decide what repair work is necessary.
Make a note of the appointment date, who attended and what they found. If work is recommended, keep the details of what was completed and whether another visit is needed.
4. Keep Evidence if the Problem Continues
Recurring mould is easier to assess when there is a clear history behind it. Take new photos if the same area becomes affected again and keep images of any damaged belongings before replacing or disposing of them.
Receipts can also be useful where costs are involved.
That evidence can support a later complaint to the council, a deposit dispute or a request for legal advice if the issue remains unresolved.
What Should a Landlord Do After Mould Is Reported?
A proper response should start with finding out why moisture is building up. Cleaning the wall or covering it with fresh paint may improve the appearance for a short time, but it does not explain why the mould formed.
The inspection should look at the mould pattern alongside the condition of the property. That can include:
- Roofs and gutters
- Plumbing and previous leaks
- External walls and windows
- Extractor fans and other ventilation
- Heating performance
- Insulation and cold surfaces
- Signs of rain penetration
Humidity monitoring and moisture readings can add useful evidence, but a single handheld meter reading should not be treated as proof of one particular type of damp. The wider pattern and building condition still need to be considered.
If the mould is widespread, keeps returning or the source is unclear, a more detailed assessment may be needed. Weather Wise Solutions provides damp and mould surveys across Staffordshire, Cheshire, Greater Manchester, Merseyside, North Wales and Derbyshire to help identify the moisture source before treatment is recommended.
How Should Mould in a Rental Property Be Fixed?
1. Resolve the Moisture Source
The repair should match the confirmed cause. That may involve stopping a plumbing leak, fixing rain penetration, improving ventilation, correcting ineffective heating or dealing with another defect identified during the inspection.
A standard mould treatment cannot solve every case because different moisture sources need different remedies.
2. Allow Damp Materials to Dry
Even after the original problem has been repaired, plaster, masonry, timber and other materials can remain damp.
Drying time depends on how wet the material became, how deeply moisture has penetrated, the temperature and the amount of airflow available. For that reason, there is no reliable universal drying period.
3. Remove Mould and Repair Damaged Finishes
Once the moisture source is controlled and the area is drying properly, visible mould can be treated. Heavily affected porous materials may need closer assessment to decide whether cleaning is sufficient or replacement is more appropriate.
Mould treatment removes contamination. Damp remediation deals with the conditions that allowed it to develop. Fresh paint or anti-mould coatings should only come after the moisture problem has been addressed.
Why Does Mould Keep Coming Back After Cleaning or Painting?
Quick recurrence usually means the underlying conditions have not changed.
If the same patch is repeatedly cleaned or painted while a leak, cold surface, poor ventilation or another moisture source remains, the mould is likely to return. Cosmetic treatment may hide the problem temporarily, but it does not remove what is feeding the growth.
Is Mould in a Rental Property Dangerous?
Damp and mould can affect your health, particularly when exposure continues over time. The main effects involve the airways and lungs, with symptoms such as coughing, wheezing and shortness of breath. Some people can also experience eye irritation, itchy skin or rashes.
Children, older adults and people with asthma, COPD, weakened immune systems or other underlying conditions may be more vulnerable to more serious effects.
The colour of mould does not tell you how harmful it is or reliably identify the species. If you are worried about symptoms, seek medical advice. A landlord should still investigate reported damp and mould promptly rather than waiting for medical evidence before acting.
What Can You Do if Your Landlord Does Not Fix the Mould?
Private renters in England should keep the issue documented and formal once a mould problem has been reported.
You can then:
- Follow up with the landlord or letting agent in writing
- Keep photographs, messages and repair records together
- Contact the local council’s private sector housing or environmental health team if serious conditions remain unresolved
- Ask for case-specific housing or legal advice before taking further action
Councils can assess rented homes under the Housing Health and Safety Rating System, which includes damp and mould as a recognised hazard. Visible mould does not automatically mean the property has a Category 1 hazard because the assessment considers the severity of the risk and the likely effect on occupants.
Since 22 June 2026, councils in England have been able to impose civil penalties of up to £7,000 in certain cases involving serious Category 1 hazards. Severe damp and mould can potentially fall within that category.
Stopping rent payments without advice can create further problems, so it should not be treated as a straightforward solution.
Does Awaab’s Law Apply to Private Rental Properties?
Awaab’s Law currently applies to social rented homes in England under a phased rollout.
The Renters’ Rights Act also provides for the rules to extend to the private rented sector, but as of September 2026, that extension has not yet been brought into force. The government roadmap still lists the timing as to be confirmed and subject to consultation.
Private tenants should therefore not assume that the statutory deadlines currently used in social housing already apply to private landlords.
Can Mould Affect Your Deposit or Lead to Compensation?
Yes, mould can affect a tenancy deposit and may also be relevant to a compensation claim, but neither outcome is automatic.
Deposit responsibility depends on what caused the mould and what the evidence shows. Pre-existing damp, reported leaks, defective ventilation or unresolved building problems are materially different from damage that can be linked to tenant actions.
Your check-in inventory, dated photographs and written repair reports can help if a deduction is disputed.
Compensation may sometimes be considered where unresolved disrepair causes damaged belongings, extra costs, loss of usable space or health effects. The outcome and value depend on the individual circumstances, so fixed amounts should not be assumed.
Stop Guessing and Find Out What Is Feeding the Mould
Persistent mould is difficult to solve when the moisture source is still uncertain. Repeated patches, unexplained damp or mould that returns after treatment can all point to a problem that needs closer inspection, especially where there is disagreement over whether condensation or a building defect is responsible.
Weather Wise Solutions offers free damp surveys and has experience assessing damp proofing, condensation and mould problems. A professional inspection can help narrow down the cause before money is spent on the wrong repair or another temporary treatment.
Landlords, property managers and tenants with the landlord’s permission can contact Weather Wise Solutions when a closer assessment is needed.
Once the cause is clear, the next step becomes much easier to judge and the risk of the mould returning can be reduced more effectively.
FAQs
Can a landlord blame a tenant for mould?
Not without evidence. A landlord should first establish why the mould is developing. Condensation may be influenced by how a home is used, but poor ventilation, cold surfaces, inadequate insulation, heating problems and building defects can also contribute. Tenant responsibility should only be considered where there is clear evidence that their actions caused or materially worsened the problem.
How quickly should a landlord deal with mould?
A landlord should respond promptly, particularly where damp or mould may affect health or cause further damage. For private rentals in England, there is no single universal deadline that applies to every mould report. The urgency depends on the severity of the problem and any associated hazard. The specific Awaab’s Law deadlines currently used in social housing should not be applied automatically to ordinary private tenancies.
Can I report my landlord to the council for mould?
Yes. Where serious damp or mould remains unresolved, private tenants in England can contact their local council. The council may inspect the property under the Housing Health and Safety Rating System, which includes damp and mould growth among its 29 hazards. Depending on the severity, the council can take enforcement action, although visible mould does not automatically mean a Category 1 hazard exists.
Can my landlord deduct money from my deposit for mould?
Yes, but a deduction is not automatically justified simply because mould is present. The cause matters, along with the condition recorded at check-in and any earlier repair reports. Photographs, inventories and written correspondence can help show whether the problem developed through an unresolved property defect or through damage attributable to the tenant.
What should I do if my landlord just paints over the mould?
Repainting may cover staining, but it will not stop mould returning if the moisture problem remains. Recurring growth should prompt further investigation into possible leaks, condensation, cold surfaces, ventilation or another source of damp. Decoration makes more sense after the cause has been corrected and affected materials have had enough time to dry.
Why is mould growing behind my wardrobe?
The wall behind a wardrobe may stay colder and receive less airflow than the rest of the room. Moisture can then remain on or near the surface for longer, creating favourable conditions for mould. Furniture position can contribute, particularly against an external wall, but persistent growth may also point to insulation, thermal bridging or another moisture problem that needs assessment.
Can I stop paying rent because my landlord has not fixed mould?
No, you should not simply stop paying rent because a mould problem has not been resolved. Government guidance for private renters says rent should continue to be paid while repairs are outstanding. Withholding rent can create tenancy and arrears problems, so obtain housing or legal advice before considering any action involving rent payments.
Can mould make a rented property unfit to live in?
Yes, severe damp and mould can contribute to a rented home being legally unfit for human habitation, but the presence of mould alone does not automatically establish that. Fitness depends on the seriousness of the condition and whether the property is reasonably suitable for occupation. Damp, inadequate ventilation and relevant HHSRS hazards are among the matters that may be considered.