Damp and mould in rental properties is the most common Category 1 hazard identified under the Housing Health and Safety Rating System (HHSRS). Following the death of two-year-old Awaab Ishak from mould exposure in a social rented home, Parliament introduced Awaab's Law — mandatory response timeframes for hazard reports. The Renters' Rights Act 2025 extends Awaab's Law to the private rented sector from 1 May 2026. Private landlords in England must now respond to damp and mould reports within statutory timeframes or face legal liability.
Category 1 hazard (e.g. severe mould, damp causing respiratory risk): emergency response within 24 hours. Investigation of any reported hazard: within 14 days. Commencement of remedial works: within 42 days of investigation. Failure to comply: tenant can apply to court for a remediation order, damages, or seek local authority intervention.
What causes damp and mould in rental properties?
- Condensation: The most common form — warm moist air contacts a cold surface (walls, windows, external corners) and water vapour condenses. Caused by cooking, bathing, drying clothes indoors, and inadequate ventilation
- Penetrating damp: Water entering through the building fabric — defective gutters, cracked render, failing pointing, flat roof leaks, or around window and door frames
- Rising damp: Groundwater rising through walls without a functioning damp-proof course — typically affects older solid-wall properties
- Plumbing leaks: Slow leaks behind walls or under floors creating localised damp and mould growth
- Poor insulation: Cold spots on walls and ceilings where insulation is absent or inadequate — a common condensation trigger in post-war housing stock
Landlord's legal duty to address damp and mould
- Section 11, Landlord and Tenant Act 1985: Landlords are obliged to keep the structure and exterior of the property in repair, including gutters, drains, external pipes, and the roof — all of which can cause damp if defective
- HHSRS (Housing Health and Safety Rating System): Damp and mould growth is a Category 1 hazard if it poses a serious risk to health — local authorities can issue improvement notices, prohibition orders, and carry out works in default
- Awaab's Law (from 1 May 2026): Mandatory response timeframes apply to any reported hazard in the private rented sector — ignoring a tenant's damp/mould report is no longer an option without legal consequences
- Fitness for human habitation: Section 9A of the Landlord and Tenant Act 1985 (as amended) requires that the property is fit for human habitation throughout the tenancy — severe damp and mould can render a property unfit
Awaab's Law response procedure for private landlords
- Receive the report: When a tenant reports damp or mould (in writing, by email, text, or verbally), acknowledge receipt immediately — record the date and nature of the report
- Investigate within 14 days: Inspect the property to assess the extent of the damp/mould and identify the cause — use a damp meter where possible
- Categorise the hazard: If the damp/mould is severe enough to be a Category 1 HHSRS hazard (i.e. it poses a serious risk to respiratory health), the emergency 24-hour response timeframe applies
- Commence remedial works within 42 days: Once the cause is identified, begin remediation — repair the building defect, treat the mould, and improve ventilation as required
- Document everything: Keep timestamped records of: the tenant's report, your inspection date, findings, remediation plan, works commenced, and works completed
- Follow up: After remediation, inspect again to confirm the mould has not returned — adjust the ventilation advice to the tenant if condensation was a contributing factor
Remediation: practical steps
- Surface mould (condensation): Treat with a fungicidal wash, repaint with anti-mould paint, improve ventilation (positive input ventilation unit, extractor fan, trickle vents), address cold spots with insulation
- Penetrating damp: Identify and repair the water ingress point (gutters, pointing, render, window seals) before treating internal mould — treating the symptom without fixing the cause will result in recurrence
- Rising damp: Inspect and repair or inject a new damp-proof course — rising damp diagnosis should be confirmed by a surveyor before expensive treatment
- Mould on soft furnishings and belongings: Severe mould episodes may damage tenant's belongings — you may be liable for replacement costs if the mould resulted from a building defect you failed to address after notification
- Temporary decant: In severe cases (Category 1 hazard), the local authority may require you to temporarily decant the tenant — arrange alternative accommodation and cover the cost
Condensation vs. structural damp — the landlord/tenant boundary
Where damp and mould is caused entirely by the tenant's lifestyle (not drying laundry, blocking vents, not using extractor fans) and the building fabric is sound, the landlord may not be in breach of their repair obligations. However, if the building contributes to the problem (poor insulation, inadequate ventilation provision), the landlord cannot simply blame the tenant. Await the Awaab's Law detailed regulations for the precise standard.
- Landlord's duty: maintain the building fabric — gutters, roof, external walls, windows, damp-proof course, and provide adequate ventilation (trickle vents, extractor fans in bathrooms and kitchens)
- Tenant's responsibility: use ventilation provided, open windows, dry laundry with windows open or in a dryer, report damp promptly
- In practice: if a tenant reports mould, inspect first and investigate the cause before attributing it to condensation — many cases have a structural contributing factor