Tackling damp and mould: What landlords need to know

With the introduction of Awaab’s Law in October 2025, public attention on damp and mould in rented homes has never been greater. While this legislation applies only to social housing, it serves as a timely reminder for private rented sector landlords about their own damp and mould responsibilities. To coincide with this increased focus, the Tenancy Deposit Scheme has put together a helpful blog for landlords, outlining what the existing laws are in the private rented sector, the steps landlords should take when damp and mould issues arise, and best practices for effectively resolving problems.

Why damp and mould needs attention

Damp and mould are more than just unsightly; they can pose serious health risks. Mould spores may trigger asthma attacks, respiratory infections, and allergies, particularly in children, the elderly, and people with weakened immune systems.

Mould is a type of fungus that thrives in damp or humid conditions. It can appear anywhere in the home but is most commonly seen as black spots on walls, ceilings, and fabrics, especially in bathrooms, bedrooms, and kitchens.

Moisture is the key factor in mould growth. This can come from:

• Occupant activities, such as showering, cooking, or drying clothes indoors without adequate ventilation.
• Building issues, including leaks, broken pipes, poor ventilation, or poorly fitting windows

Because moisture can come from both people and the property itself, responsibility for damp and mould isn’t always clear-cut.

However, for landlords there is a legal duty to prevent and address these issues. Under the Homes (Fitness for Human Habitation) Act 2018, rented homes must be safe and fit for habitation, which includes being free from serious damp and mould. This involves taking reasonable steps to maintain roofs, gutters, walls, plumbing, ventilation, and heating systems, helping to reduce the risk of damp and protect tenants’ health.

Preventive steps for damp and mould

Once landlords understand the risks and their legal responsibilities, the next step is proactive management to prevent damp and mould from becoming a serious problem. Early detection and intervention can stop small issues from escalating into significant health hazards or costly repairs.

1. Carry out regular inspections

Landlords should schedule in-person inspections to check for signs of damp and mould. While photos from tenants can be helpful, they may not reveal the full extent of the issue. During inspections, look for:

External checks:

• Damaged or blocked pipes, gutters, or downpipes
• Ill-fitting windows or broken seals
• Structural defects such as cracks in render or the foundation
• Missing or compromised damp-proof courses (This is a protective barrier near the base of the walls that stops moisture from rising from the ground)

Internal checks:

• Condensation on windows or walls
• Peeling wallpaper
• Visible damp or staining
• Defective plaster
• Consistently high relative humidity (assessed with moisture meters or environmental monitors)
• Low insulation or internal wall temperatures
• Broken or absent ventilation systems
• Ineffective heating systems
• Musty odours that might indicate hidden mould (Even without visible mould, a persistent smell may indicate hidden growth).

Complex cases may require additional testing, including thermography or microbial sampling, and landlords should seek guidance from qualified professionals.

2. Act quickly and safely

When mould is discovered, swift action is critical.  For small areas that are caused by lack of ventilation or something easily fixable, landlords or tenants may be able to manage cleaning with appropriate products. However, larger infestations should be handled by professionals.

3. Maintain records

Documenting inspections, repairs, and communications with tenants is important. This provides a clear record of the landlord’s proactive steps, which can be useful in deposit disputes or if a local council becomes involved.

4. Tenant advice

Landlords can help prevent damp and mould by offering tenants practical advice on day-to-day habits. This includes encouraging regular ventilation, particularly when cooking, showering, or drying clothes indoors, and maintaining a consistent, moderate temperature throughout the home to reduce condensation. Tenants should be encouraged to promptly report any signs of damp or mould, and landlords should make the reporting process clear and easy. Providing tenants with this guidance supports a collaborative approach, helping to maintain a healthy home, prevent serious issues, and reduce the likelihood of disputes over responsibility.

Safe mould removal

Once you’ve identified damp or mould, swift removal and remediation is crucial to protect health and prevent spread. Here are best-practice steps for mould removal:

1. Document the problem: Before cleaning, photograph and mark the affected areas. This creates a record for your files (or for any potential insurance or deposit dispute) and helps in tracking if mould returns.
    
2. Choose who will clean: For small patches of surface mould (e.g. a bathroom ceiling spot) tenants can often clean it themselves using household mould remover or a mild bleach solution, if they are willing and properly equipped. However, for large or recurring mould infestations, or if the mould covers a big area (e.g. an entire wall) or is reoccurring, bring in qualified professionals. Experts will not only remove the mould safely but also address underlying causes.
    
3. Use protective gear: Never attempt mould removal unprotected! Anyone cleaning mould should wear a face mask, rubber gloves, and goggles or eye protection. This prevents inhaling mould spores or getting them on your skin and in your eyes.
    
4. Contain and ventilate: When treating the mould, keep internal doors closed to confine any dislodged spores to that room and prevent them spreading through the rest of the house. At the same time, open windows in the affected area (if possible) to provide fresh air and allow spores to escape outside. Good ventilation during and after cleaning will help dry out the area and flush out any airborne mould.
    
5. Clean up and dispose properly: After removal, wash or dispose of all materials used. For instance, wash contaminated rags separately on a hot wash, or double-bag and throw away any cleaning equipment that came into contact with mould. Also, carefully remove and discard any mould-infested porous materials (like mildewed carpet or rotten wood) that cannot be fully cleaned. Thorough clean-up ensures that remaining spores don’t re-seed a new colony.

Remember, simply wiping away mould is not a permanent solution. Mould is a symptom of a moisture problem, and unless the damp source is fixed the mould will likely return. That’s why removal must go hand-in-hand with addressing the cause, be it a leak, lack of ventilation, or tenant lifestyle factors. After cleaning, continue monitoring the area and be prepared to investigate further if you see or smell signs of mould coming back

Engage with qualified professionals

While internal and external checks are useful, landlords should not rely solely on self-diagnosis if the problem is severe and persists. A proper in-person inspection is essential to evaluate severity, underlying causes, and potential health risks. Qualified contractors should perform assessments, and landlords can involve local authorities under the Housing Health and Safety Rating System (HHSRS) when necessary.

To support landlords in maintaining safe and healthy homes, the Tenancy Deposit Scheme partners with organisations such as Dampsmart, who provide practical guidance, contractor support, and tools to manage and prevent damp and mould effectively.

When damp and mould issues turn into a deposit dispute

Issues with damp and mould can sometimes lead to disputes over tenancy deposits, particularly when deciding whether damage was caused by tenant behaviour or property defects. Landlords are responsible for ensuring the property is free from structural issues, defective plumbing, ventilation, or insulation that could cause damp or mould. And tenants are expected to maintain reasonable levels of heating and ventilation, promptly report issues, and avoid behaviours that exacerbate moisture problems, such as blocking vents or failing to manage condensation.

If a dispute arises at the end of a tenancy, deposit protection schemes like TDS can help adjudicate fairly. Here, landlords should maintain detailed records of property condition, including photographs, inspection reports, and maintenance logs, and whether the tenants reported any problems in writing. Clear communication and evidence help establish whether damp and mould resulted from lack of cleaning, property defects, or a combination, ensuring a fair resolution and reducing the risk of unnecessary deductions.

For more detailed guidance, download the Tenancy Deposit Scheme’s in-depth guide to mould and damp here.

Not with the Tenancy Deposit Scheme?

Visit our TDS Help Centre to find more guides, tools and templates, all designed to make the life of a landlord easier.  Some of our resources are only available to landlords who use the free deposit protection scheme at TDS Custodial or the insured scheme at TDS Insured. You can access all templates, tools and the full tenancy deposit management dashboard by joining the Tenancy Deposit Scheme.