Damp and mould are among the most significant health risks in residential properties. Exposure to mould has been associated with respiratory conditions, allergic reactions, and in severe cases fatal outcomes, as the case of Awaab Ishak made tragically visible. The UK Government's official guidance is explicit: damp and mould are not lifestyle or behavioural issues to be attributed to tenants. They are building performance issues, and the landlord is responsible for the building.
This position has legal force in 2026. The Homes (Fitness for Human Habitation) Act 2018 requires rental properties to be free of serious damp throughout the tenancy. The Housing Health and Safety Rating System gives local authorities powers to take enforcement action — including prohibition orders and improvement notices — where a Category 1 hazard such as damp or excess cold is identified. Properties with active damp conditions may not lawfully be let, and landlords who fail to address reported damp issues face civil penalties and Rent Repayment Orders.
Looking ahead, the Awaab's Law framework — which currently imposes mandatory response timescales on social housing landlords — is expected to be extended to the private rented sector. No implementation date has been confirmed as of May 2026, with 2027 the most widely cited expectation. Landlords should treat the Awaab's Law framework as the standard to prepare for, and the current HHSRS enforcement regime as the legal baseline that already applies.
Diagnosing the Type of Damp
Before commissioning any remediation work, the type of damp must be correctly identified. Different types have different causes and require fundamentally different fixes. A "bleach and repaint" approach addresses the visible symptom without touching the underlying cause, and the mould will return.
| Type | Primary Signs | Common Fixes |
|---|---|---|
| Condensation | Black spot mould in corners and behind furniture; misted windows; no external source of water | Upgrade extractor fans to humidistat-controlled models; ensure trickle vents are open; improve insulation |
| Penetrating damp | Localised wet patches appearing after rain; salt deposits on walls; damp that varies with weather | Repair external render; clear blocked gutters; fix roof leaks or failed flashings |
| Rising damp | Tide marks and salt deposits up to one metre from floor level; rotten skirting boards; consistent dampness at low level | Install or repair damp proof course; lower external ground levels that bridge the DPC |
| Traumatic (burst or leaking pipe) | Sudden saturation of wall or ceiling; staining that maps to a pipe route | Immediate leak repair followed by professional drying and decontamination |
Condensation is by far the most common form of damp in UK rental properties. It occurs when warm, moisture-laden air comes into contact with cold surfaces and deposits moisture. It does not mean the tenant is generating excessive moisture — it means the building's ventilation and insulation are insufficient to manage the moisture that normal domestic activity produces. The fix is always about the building's performance, not the tenant's behaviour.
Legal Obligations in 2026
The fitness for habitation obligation under the Homes (Fitness for Human Habitation) Act 2018 requires rental properties to be fit throughout the tenancy. A property with active, significant damp or mould may be legally unfit for habitation, and tenants have the right to take direct court action against landlords who fail to address unfitness.
The Housing Health and Safety Rating System provides the current enforcement framework: local authorities must take action on Category 1 hazards — of which damp and excess cold are the most common — using improvement notices, prohibition orders, and civil penalties. The Renters' Rights Act 2025 strengthened local authority enforcement powers from 1 May 2026, increasing civil penalty ceilings and expanding investigatory tools.
The Decent Homes Standard will extend to the private rented sector, but not until 2035 under Phase 3 of the Renters' Rights Act implementation. The Awaab's Law extension to the PRS — which will introduce mandatory investigation and remediation timescales — is also not yet in force and is subject to government consultation, with 2027 the most widely cited expectation.
Attributing mould to tenant lifestyle choices (drying clothes on radiators, not ventilating, cooking without extraction) is no longer an adequate response under current government guidance — and will become even more clearly insufficient when Awaab's Law extends to the PRS. To successfully argue that a tenant is contributing to a damp condition, the landlord must provide professional evidence that the property's ventilation and insulation systems are fully functional. The presumption of responsibility rests with the landlord.
The Response Model
When damp or mould is reported or observed during an inspection, the response should follow a defined model. Acknowledge the report promptly in writing and identify whether any occupant is in a vulnerable group — those with respiratory conditions, young children, or immune-compromised individuals face greater health risks and should be treated as elevated priority.
Commission a professional inspection to identify the type of damp and its root cause. The Awaab's Law framework for social housing requires this within 14 calendar days of awareness — private landlords should apply the same standard as both good practice and preparation for when the PRS extension arrives. Once the inspection is complete, provide the tenant with a written summary of findings and required works, including expected start and completion dates.
Where a hazard poses an immediate health risk — significant mould in a bedroom occupied by an infant, active water ingress making the property uninhabitable — the response must be urgent, ideally within 24 hours. This may involve deploying industrial dehumidification, professional mould treatment, or arranging temporary alternative accommodation.
The fundamental principle in all responses to damp is that temporary measures without root cause remediation are not adequate. Painting over mould without addressing the ventilation or water ingress that caused it will generate a repeat report within months, and a pattern of inadequate responses is exactly what local authority enforcement action and — from 2028 — Ombudsman complaints will focus on.
Preventative Measures
Several property maintenance actions significantly reduce damp risk before it generates a tenant report or enforcement investigation. Extractor fans in kitchens and bathrooms should be humidistat-controlled — triggered automatically by moisture levels rather than relying on manual operation. Trickle vents in windows should be confirmed open and unobstructed at the start of each tenancy. Gutters should be cleared annually to prevent water ingress from overflow. External pointing and render should be inspected in spring and autumn to identify any deterioration that creates a penetrating damp risk.
For properties with known insulation limitations, proactive insulation improvement — whether cavity wall, loft, or internal wall insulation as appropriate — reduces the cold surface temperatures that drive condensation. The confirmed 1 October 2030 deadline for EPC band C means most landlords will need to address insulation in older properties regardless, and early investment reduces both the damp risk and the compliance cost of leaving improvements until the deadline.
Official Damp and Mould Guidance
The definitive GOV.UK guide on health risks and landlord remediation duties for damp and mould.
Awaab's Law Timeframes
The social housing framework that is expected to extend to the private rented sector from around 2027.
Approved Document F (Ventilation)
Legal requirements for fan flow rates and background ventilation.
Shelter: Fitness for Habitation
Legal analysis of when damp allows a tenant to take direct court action.
This article reflects our understanding of the law at the time of publication. It is for general guidance only and does not constitute legal advice. Always verify against GOV.UK or seek qualified legal advice before acting.
