Damp and Mould Prevention: Our Advice for Landlords

Dampness, condensation and mould are common problems in UK rental properties, particularly in older buildings. These issues present a frequent source of tenant complaints and, more importantly, can pose serious health risks.

With recent legislative changes including Awaab’s Law and the Renters’ Rights Act 2025, landlords now face stricter legal obligations and tighter timeframes for addressing these hazards. This comprehensive guide explains what landlords need to know about damp and mould, including their responsibilities, prevention strategies, and the latest legal requirements.

What is Damp?

Damp is the presence of excess moisture in a property. It typically manifests as wet patches on walls, water stains, peeling paint or wallpaper, and often produces a musty smell. The issue usually materialises as black spot mould on walls, or surfaces that feel cold and wet to the touch. Understanding the different types of damp is essential for identifying the cause and implementing effective solutions.

Rising Damp

Rising damp occurs when groundwater travels upwards through the porous materials in floors and walls by capillary action. It typically affects the lower parts of ground floor rooms up to a height of approximately one metre.

Signs include tide marks on walls, salt deposits, and deteriorating plaster at ground level. Rising damp is more common in older properties, particularly those built before damp-proof courses became standard. If the property has a damp-proof course that has failed or been breached, this will need professional repair or replacement.

Penetrating Damp

Penetrating damp is caused by water leaking through walls, roofs, or around windows and doors from outside the building. This often results from structural defects such as damaged roof tiles, faulty guttering, cracked rendering, deteriorating pointing, or defective window seals.

Unlike rising damp, penetrating damp can occur at any level of the building and typically worsens during heavy rain. The affected areas often spread outward from a central point where water is entering.

Condensation Damp

Condensation is the most common cause of damp in rental properties. It occurs when warm, moist air comes into contact with cold surfaces such as windows, external walls, or areas with poor air circulation. The moisture in the air condenses into water droplets on these cold surfaces.

If not addressed, this creates ideal conditions for mould growth. Condensation is particularly prevalent in bathrooms and kitchens where moisture levels are naturally higher, and in bedrooms where overnight breathing adds humidity to enclosed spaces.

What is Mould?

Mould is a type of fungus that thrives in damp, humid environments. It appears as fuzzy patches that can be black, green, white, or grey in colour, and typically has a musty odour. Mould reproduces by releasing microscopic spores into the air, which can then settle on other damp surfaces and begin new growth. While mould is primarily an environmental issue caused by excess moisture rather than structural defects, it often indicates underlying problems with ventilation, insulation, or heating within the property.

Common locations for mould include bathroom ceilings and tile grout, around windows where condensation collects, behind furniture placed against external walls, in corners of rooms with poor air circulation, and in any area that has experienced water damage or flooding. Black mould, particularly the species Stachybotrys chartarum, is especially concerning as it can produce mycotoxins that pose additional health risks.

Health Risks of Damp and Mould

Damp and mould in a property can have significant negative impacts on occupants’ health. The NHS recognises that mould spores act as allergens that can cause allergic reactions when inhaled or when they come into contact with skin. Prolonged exposure to damp and mouldy conditions has been linked to a range of health problems, and certain groups are particularly vulnerable to these effects.

Respiratory Problems

Exposure to mould spores can irritate the airways and lungs, leading to symptoms including persistent coughing, wheezing, shortness of breath, and chest tightness. Research has shown that people living in damp homes are more likely to develop respiratory infections and bronchitis. For those with pre-existing conditions such as asthma or chronic obstructive pulmonary disease (COPD), damp and mould can significantly worsen symptoms and trigger attacks. Studies indicate that children living in damp homes are up to three times more likely to develop breathing problems.

Allergic Reactions

Mould spores are common allergens that can trigger reactions including sneezing, runny or blocked nose, watery and itchy eyes, and skin rashes or eczema flare-ups. These symptoms can occur even in individuals who have not previously had allergies. Allergic reactions may be immediate or develop over time with repeated exposure. Damp conditions also encourage the proliferation of dust mites, another significant allergen that can compound health problems.

Vulnerable Groups

Certain individuals are particularly susceptible to the health effects of damp and mould. These include babies and young children whose respiratory systems and immune systems are still developing, elderly people with weakened immunity or existing health conditions, pregnant women, people with asthma or other respiratory conditions, those with allergies or eczema, and individuals with compromised immune systems due to illness or medical treatment. The tragic death of two-year-old Awaab Ishak in 2020 from prolonged exposure to mould in his family’s social housing flat brought national attention to the serious risks posed by inadequate responses to damp and mould problems.

Mental Health Impact

The health effects of damp and mould extend beyond physical symptoms. Research suggests that living in cold, damp, and mouldy conditions can increase stress and anxiety, reduce sleep quality, and contribute to depression. The ongoing worry about health, the unpleasant living conditions, and potential disputes with landlords about repairs can all take a toll on tenants’ mental wellbeing.

Property Damage from Damp and Mould

Beyond health concerns, damp and mould can cause substantial damage to the property itself, leading to costly repairs and reduced property value. Paint may bubble, blister, and peel away from walls and ceilings. Plasterwork can deteriorate, become soft, and eventually crumble. Wallpaper loosens and develops unsightly staining. External masonry, render, and pointing can crack and erode. Wooden fixtures including window frames, skirting boards, and door frames may warp, rot, and require replacement.

Mould leaves black or coloured spots and persistent staining on walls, ceilings, fabrics, and soft furnishings. Even after the mould itself is removed, staining may remain and require redecoration. In severe cases, mould can penetrate deep into porous materials, making complete removal difficult without replacing affected components. Tenants’ belongings including furniture, clothing, and bedding can also be damaged by mould, potentially leading to compensation claims.

Landlord Responsibilities and Legal Framework

Landlords have clear legal obligations to address damp and mould in their rental properties. Several pieces of legislation establish these duties, and recent changes have significantly strengthened tenant protections and landlord accountability.

Landlord and Tenant Act 1985

Section 11 of this Act requires landlords to keep in repair the structure and exterior of the property, including drains, gutters, and external pipes. Landlords must also maintain installations for the supply of water, gas, electricity, sanitation, space heating, and water heating. Where damp is caused by disrepair falling within these obligations, the landlord is legally responsible for remedying it.

Homes (Fitness for Human Habitation) Act 2018

This Act requires landlords to ensure their properties are fit for human habitation at the start of the tenancy and throughout its duration. A property affected by serious damp and mould may be considered unfit for habitation, giving tenants grounds for legal action. The Act covers issues including inadequate ventilation, problems with drainage, and issues affecting the health of occupants.

Housing Health and Safety Rating System (HHSRS)

Under the Housing Act 2004, local authorities assess properties using the HHSRS, which rates 29 potential hazards including damp and mould. Where damp and mould present a serious risk to health, they may be classified as a Category 1 hazard, requiring the local authority to take enforcement action. This can include serving improvement notices, prohibition orders, or emergency remedial action notices on landlords.

Environmental Protection Act 1990

Where damp and mould are prejudicial to health, they may constitute a ‘statutory nuisance’ under this Act. Tenants can request an inspection by their local authority’s environmental health team. If a statutory nuisance is identified, the environmental health officer must serve an abatement notice requiring the landlord to address the problem. Failure to comply can result in prosecution and fines.

Awaab’s Law: New Mandatory Timeframes

Awaab’s Law, named in memory of Awaab Ishak, came into force for social housing landlords on 27 October 2025 through the Social Housing (Regulation) Act 2023. This landmark legislation introduces strict legal timeframes for landlords to address damp, mould, and other hazards. While currently applicable only to social landlords, the Renters’ Rights Act 2025 includes provisions to extend these requirements to private landlords following consultation.

Key Timeframes Under Awaab’s Law

• Emergency hazards: Must be investigated and made safe within 24 hours of being reported. If the property cannot be made safe, alternative accommodation must be offered.
• Significant hazards including damp and mould: Must be investigated within 10 working days of being notified.
• Written findings: Tenants must receive a written summary of investigation findings within 3 working days of the investigation concluding.
• Repairs: Must begin within 5 working days of the investigation, or within 12 weeks if works are complex.
• Alternative accommodation: Must be offered if repairs cannot be completed within required timeframes.

Extension to Private Landlords

The government has confirmed its intention to extend Awaab’s Law to the private rented sector through the Renters’ Rights Act 2025.

While the exact implementation date and specific timeframes for private landlords will be determined following consultation, landlords should prepare now by implementing robust systems for receiving, recording, and responding to tenant reports of damp and mould. The direction of travel is clear: all landlords will eventually face mandatory timeframes for addressing these hazards.

Renters’ Rights Act 2025

The Renters’ Rights Act 2025 received Royal Assent on 27 October 2025 and will be implemented in phases beginning 1 May 2026. This represents the most significant reform of the private rented sector in a generation. Key provisions affecting damp and mould responsibilities include the extension of Awaab’s Law to private landlords, the application of the Decent Homes Standard to private rented properties, and enhanced local authority enforcement powers.

The reformed Decent Homes Standard will include a specific criterion requiring properties to be ‘free from damp and mould’ beyond the most minor levels. Properties will fail this criterion if damp and mould are assessed as falling within bands A to H under the HHSRS scoring system. Local authority enforcement powers came into effect from 27 December 2025, allowing councils to investigate suspected breaches and take action against non-compliant landlords.

Who is Responsible for Dealing with Damp and Mould?

Government guidance published in 2024 makes unambiguously clear that landlords are responsible for identifying and addressing the underlying causes of damp and mould.

The guidance explicitly states that damp and mould ‘are not the result of lifestyle choices’ and that it is unacceptable for landlords to blame tenants for these problems without proper investigation.

Landlord Responsibilities

Landlords must treat reports of damp and mould with the utmost seriousness and act promptly to protect tenant health. They are responsible for investigating to identify the root cause, whether this is structural issues, inadequate ventilation, insufficient insulation, heating system problems, or building defects.

The landlord must then implement appropriate solutions and cannot simply assume the problem is caused by tenant behaviour. Where the cause is unclear, landlords should commission a professional damp survey at their own expense.

Tenant Responsibilities

While the primary responsibility lies with landlords, tenants do have a duty to act in a ‘tenant-like manner’ and take reasonable care of the property. This includes using ventilation facilities provided (such as extractor fans and trickle vents), allowing adequate heating, wiping away condensation, reporting problems promptly, and allowing access for inspections and repairs.

However, landlords cannot rely on lifestyle factors as a defence if the property is inadequately designed, insulated, or ventilated for normal residential use.

Notification Requirements

Landlords are only obligated to repair problems they know about. Tenants must report damp and mould issues, and it is advisable to do so in writing to create a clear record. Once notified, the landlord’s duties and any applicable timeframes begin. Landlords should establish clear, accessible reporting systems and respond promptly to all reports.

Keeping detailed records of all communications, inspections, and works is essential for demonstrating compliance with legal obligations.

Preventing Damp and Mould

Prevention is always better than cure. Taking proactive measures to prevent damp and mould from developing in the first place protects tenant health, preserves property condition, and avoids costly remediation.

The key factors are ensuring adequate ventilation, appropriate insulation, effective heating, and maintaining the building fabric in good condition.

Ventilation

Adequate ventilation is essential for removing moisture-laden air from the property and preventing condensation. Landlords should ensure that extractor fans are installed in bathrooms and kitchens and that these are in good working order.

Windows should have trickle vents where possible, and these should not be blocked or painted shut. Consider installing mechanical ventilation with heat recovery (MVHR) in properties with persistent condensation problems. Passive vents in appropriate locations can also improve air circulation.

Insulation

Proper insulation keeps internal surfaces warmer, reducing the likelihood of condensation forming. Consider external wall insulation, internal wall insulation, cavity wall filling, loft insulation, and floor insulation where appropriate. Double or triple glazing prevents condensation on windows and improves overall thermal efficiency.

Cold bridges, where building elements conduct cold from outside, should be identified and addressed. Note that improving insulation should always be accompanied by adequate ventilation to prevent trapping moisture inside the building.

Heating

An effective heating system that tenants can afford to use is crucial for preventing condensation. Central heating should be in good working order with regular servicing. Ensure radiators are appropriately sized and positioned.

Where possible, heating should maintain a consistent moderate temperature rather than alternating between very hot and very cold. Consider the energy efficiency of the property overall, as tenants may under-heat unaffordable properties, leading to condensation problems.

Building Maintenance

Regular maintenance prevents the structural defects that cause penetrating and rising damp. Inspect and maintain roofs, guttering, downpipes, and drainage regularly. Check and repair pointing, rendering, and external walls. Ensure damp-proof courses are intact and effective. Repair any leaks in plumbing promptly. Seal gaps around windows and doors. Address any signs of damp or water ingress immediately before problems escalate.

Regular Inspections

Conduct regular property inspections to identify early signs of damp and mould before they become serious. Check vulnerable areas including bathrooms, kitchens, around windows, behind furniture, and in corners with poor air circulation. Use a moisture meter to identify hidden damp. Following any repairs for damp or mould, revisit the property at least six weeks later to verify the measures have been effective.

Guidance for Tenants

As a landlord, providing clear guidance to tenants on preventing condensation and mould can help maintain the property in good condition. While tenants’ lifestyle cannot be blamed for damp problems caused by inadequate property design, good habits can minimise moisture levels and help prevent condensation forming on properly ventilated and heated properties.

Practical Advice to Share with Tenants

• Ventilation: Use extractor fans when cooking, showering, or bathing. Open windows briefly each day to allow air circulation, particularly in bedrooms after waking. Keep trickle vents open. Avoid blocking air vents.
• Moisture reduction: Wipe condensation from windows and windowsills promptly. Avoid drying clothes on radiators or indoors without adequate ventilation. Use a vented tumble dryer or dry clothes outside where possible. Keep lids on pans when cooking.
• Heating: Maintain a consistent moderate temperature throughout the property rather than heating and cooling dramatically. Keep the home above 15°C in cold weather to prevent condensation. Report any heating problems promptly.
• Furniture placement: Keep furniture slightly away from external walls to allow air circulation. Avoid overfilling wardrobes and cupboards on external walls.
• Reporting: Report any signs of damp or mould immediately in writing. Allow access for inspections and repairs. Do not attempt to cover up or paint over mould.
• Avoid problematic heating: Portable gas or paraffin heaters release significant moisture into the air and should be avoided.

Responding to Damp and Mould Reports

When a tenant reports damp or mould, landlords should respond promptly and systematically. A structured approach ensures legal compliance, protects tenant health, and creates a clear record of actions taken.

Step-by-Step Response Process

• Acknowledge: Respond to the report within 24 hours, confirming receipt and outlining next steps.
• Investigate: Arrange an inspection as soon as possible to assess the extent and identify the cause. For complex cases, commission a professional damp survey.
• Document: Take photographs, record moisture readings, and document findings thoroughly.
• Communicate: Provide the tenant with written findings and explain the planned remediation works.
• Remediate: Address the underlying cause, not just the visible symptoms. Remove mould safely using appropriate methods and products.
• Follow up: Check back at least six weeks after works to ensure the problem has been resolved.
• Record keeping: Maintain comprehensive records of all communications, inspections, and works for at least five years.

When to Seek Professional Help

While minor surface mould can often be cleaned with appropriate products, professional intervention is advisable for significant or recurring problems. Consider commissioning a professional damp survey when the cause of damp is unclear, when problems persist despite initial remediation, when structural defects are suspected, or when mould covers a large area. Professional mould remediation may be required for extensive infestations or where mould has penetrated deep into materials. Accredited surveyors can provide reports that satisfy insurers, mortgage lenders, and regulatory bodies.

Conclusion

Damp and mould present serious risks to tenant health and property condition, and landlords have clear legal responsibilities to address these issues. With the implementation of Awaab’s Law and the Renters’ Rights Act 2025, these obligations are being strengthened with mandatory timeframes and enhanced enforcement powers. Proactive prevention through proper ventilation, insulation, heating, and building maintenance is always preferable to reactive remediation.

Landlords who take damp and mould seriously, respond promptly to reports, and maintain good communication with tenants will not only comply with their legal duties but also protect their properties and maintain positive tenant relationships. The direction of regulatory change is clear: standards are rising, and landlords must rise with them.

If you’re a landlord and need more information or advice, or would like a free lettings valuation, get in touch today.