Mould in Rental Properties: What Landlords Need to Know—and What You Must Tell Your Tenants

Damp and mould should never be dismissed as merely a cosmetic problem. It can damage a property, destroy tenants’ belongings and cause or worsen respiratory problems, asthma, allergies and infections. Children, older people and anyone with an existing health condition may be particularly vulnerable.

The government’s position is clear: landlords should not automatically blame a tenant’s “lifestyle.” The landlord or managing agent must investigate the underlying cause and take appropriate action.

What causes mould?

Mould grows where moisture remains on cold surfaces. Common causes include:

• Leaking roofs, gutters or pipes

• Defective brickwork or external render

• Failed seals around windows, baths or showers

• Inadequate heating

• Missing or defective extractor fans

• Blocked air vents or trickle vents

• Poor insulation and cold bridging

• Rising or penetrating damp

• Condensation from cooking, bathing, drying clothes and everyday occupation

More than one cause may be present. A tenant can produce moisture through normal daily activities while a poorly insulated or inadequately ventilated property makes the problem considerably worse.

Telling a tenant simply to open the windows is not a proper investigation.

The landlord’s legal responsibilities

Under the Homes (Fitness for Human Habitation) Act 2018, rented homes must remain fit for human habitation at the beginning of and throughout the tenancy. Serious damp, mould, inadequate ventilation and excess cold may make a property unfit.

A tenant may take court action if the landlord fails to deal with serious hazards. The court can order the landlord to complete the necessary work and may award compensation. Local authorities also have enforcement powers under the Housing Health and Safety Rating System.

Landlords may also be responsible for repairing the structure and exterior of the property and installations for water, heating and sanitation under section 11 of the Landlord and Tenant Act 1985.

Once a landlord or agent knows about a potential hazard, it must be addressed within a reasonable period. What is reasonable depends on the seriousness of the problem, its effect on the household and the work required. Hazards in the common parts of blocks and HMOs can create more immediate responsibility.

Does Awaab’s Law apply to private landlords?

Awaab’s Law currently imposes fixed damp-and-mould response times on social landlords. Significant damp and mould must generally be investigated within 10 working days, the property made safe within five working days following the investigation, and emergency hazards addressed within 24 hours.

The Renters’ Rights Act 2025 provides for Awaab’s Law to be extended to the private rented sector. However, as of September 2026, the detailed private-sector timescales still require regulations and further implementation work.

Private landlords should not falsely claim that the social-housing deadlines already apply directly to every private tenancy. Equally, they should not use the phased implementation as an excuse to delay. Existing repair, fitness and housing-safety duties already apply.

What landlords and agents should do when mould is reported

1. Record the report immediately

Record:

• The date and time of the report

• The affected rooms

• Photographs or videos supplied

• How long the problem has existed

• Whether water is actively entering the property

• Whether heating, windows or extractor fans are working

• Whether children, older residents or vulnerable occupants are affected

• Any reported health symptoms

Do not make a medical diagnosis. If someone reports serious breathing difficulties or an immediate health emergency, advise them to seek appropriate medical assistance.

2. Assess the urgency

An active leak, collapsed ceiling, dangerous electrical contact, severe water penetration or serious health risk may require an emergency response.

Less urgent reports still need prompt investigation. Leaving mould for weeks while debating responsibility is poor management and may expose the landlord to enforcement or a legal claim.

3. Arrange an inspection

Inspect the affected area and, where appropriate:

• Test moisture levels

• Examine external walls, roofs and gutters

• Check plumbing and bathroom seals

• Test extractor fans

• Check trickle vents and air bricks

• Review heating provision

• Look for cold bridges and insulation defects

• Check behind furniture and inside cupboards

• Consider whether neighbouring flats or common parts are contributing

Except in a genuine emergency, landlords will normally need to give at least 24 hours’ written notice and attend at a reasonable time. Keep evidence of every attempt to arrange access.

4. Fix the cause—not merely the visible mould

Painting over mould is not a repair.

The work may require:

• Repairing leaks or defective gutters

• Replacing or upgrading extractor fans

• Clearing or restoring ventilation

• Repairing external walls or failed seals

• Improving insulation

• Addressing inadequate heating

• Treating and safely removing contaminated materials

• Replacing damaged plasterboard, flooring or furnishings where necessary

Mould-resistant paint may form part of the final treatment, but only after the source of the moisture has been identified and controlled.

5. Confirm the outcome in writing

Tell the tenant:

• What was found

• What immediate action was taken

• What permanent work is required

• Who will complete it

• The expected timetable

• Whether another inspection is required

• What the tenant should do if the mould returns

Keep inspection reports, photographs, contractor invoices, messages and completion evidence.

Tenants must be informed before the colder months

Landlords and managing agents should contact tenants before autumn and winter to remind them how to recognise and report condensation, damp and mould.

The colder months create the greatest risk because properties are heated less consistently, windows remain closed for longer and moisture condenses on cold walls, windows and ceilings.

Tenants must be told to contact their landlord or managing agent immediately when they first notice:

• Persistent condensation

• Small black marks around windows or ceilings

• Damp patches

• Peeling wallpaper or paint

• A musty smell

• Water staining

• Defective heating or extractor fans

• Leaks or water penetration

Tenants should not wait until an entire wall or ceiling has turned black.

Early reporting allows the landlord to inspect the property, identify the cause and prevent a small problem from becoming serious. Delayed reporting can allow mould to spread behind furniture, damage plaster, flooring, decorations and belongings, and increase the scale and cost of the remedial work.

However, late reporting does not automatically remove the landlord’s responsibility. The cause must still be investigated properly.

What tenants should be told

Tenants should receive clear, practical advice without being blamed.

Ask tenants to:

• Report damp, leaks, condensation or mould immediately

• Send photographs and identify the affected rooms

• Use working extractor fans when cooking or bathing

• Keep trickle vents and permanent air vents open

• Use pan lids and avoid allowing steam to spread

• Dry clothes outside or use suitable ventilation where reasonably possible

• Maintain reasonable background heating

• Wipe heavy condensation from windows and sills

• Leave a small gap between large furniture and cold external walls

• Avoid blocking radiators, vents and extractor fans

• Permit reasonable access for inspections and repairs

• Report defective heating, windows or ventilation immediately

These steps may reduce condensation, but they do not remove the landlord’s responsibility to investigate structural defects, leaks, inadequate insulation, defective ventilation or insufficient heating.

Suggested pre-winter notice for tenants

Important: Damp, Condensation and Mould

As we approach the colder months, please check your home regularly for condensation, damp, water penetration or mould.

If you notice even a small amount of mould, a damp patch, peeling paint, water staining or a persistent musty smell, contact your landlord or managing agent immediately.

Please do not wait until the mould has spread or an entire wall has turned black. Early notification allows us to inspect the property, identify the cause and prevent further damage.

When reporting a problem, please provide:

• Your name and property address

• The rooms affected

• Photographs or videos

• The date the problem was first noticed

• Details of any visible leak or water damage

• Confirmation of whether the heating and extractor fans are working

• Details of anyone in the household who may be particularly vulnerable

Please continue using the heating and ventilation provided, keep permanent vents clear and allow reasonable access for inspection and repairs.

We will investigate the cause rather than automatically assume that the problem results from how the property is occupied.

The mistake landlords must avoid

The most damaging response is:

“It is condensation. Open the windows.”

That conclusion should not be reached without inspecting the property.

Sometimes tenant behaviour contributes to condensation. Sometimes the cause is a building defect. Frequently, it is a combination of occupation, temperature, insulation and ventilation.

The correct response is early reporting, proper inspection and effective action—not blame.

How MyEstate can help

MyEstate Luton Limited supports landlords with:

• Damp-and-mould inspections

• Property condition reports

• Pre-winter tenant communications

• Repair coordination

• Routine tenancy inspections

• HMO and licensing compliance

• Contractor management

• Ongoing property management

If your tenant has reported damp or mould, deal with it before it becomes a health concern, formal complaint or enforcement matter.

MyEstate Luton Limited
Sales • Lettings • Property Management • Block Management • Land & Development

Telephone: 01582 380330
Email: luton@my-estate.co.uk
Website: www.my-estate.co.uk

This article provides general information for properties in England and does not constitute legal or medical advice. Duties and statutory timescales may change as further Renters’ Rights Act regulations are introduced.