Damp and mould in your rented home: a practical guide

Almost half of private renters in England are currently living with damp, cold or mould — yet more than a third of those people have never reported it to their landlord. The most common reason is fear: of eviction, of a rent increase, of being seen as trouble.

That fear is now legally less justified than it has ever been. But knowing your rights is only part of the picture. The other part is understanding what you are actually looking at — because not all damp is the same, and the type determines both the urgency and the repair your landlord is responsible for making.

The three types of damp — and how to tell them apart

Condensation mould

The most common type. Appears as black or grey spotting, usually around window frames, in corners near the ceiling, or on external-facing walls. It is caused by warm, moist air hitting a cold surface — cooking, showering, and breathing all produce moisture that has to go somewhere.

Landlords sometimes try to attribute this entirely to tenant behaviour ("you need to open windows more"). That is occasionally fair — but if the property has poor insulation, no extractor fan in the bathroom or kitchen, or inadequate heating, the structure itself is contributing to the problem. That is the landlord's responsibility, not yours.

Penetrating damp

Comes through an external wall, roof, or around a window frame. Look for a damp patch that appears or worsens after rain, often with tide marks or a yellowish stain. It typically has a clear source: a cracked render, a missing roof tile, a failed seal around a window, a blocked or broken gutter directing water against the wall.

This is almost always a structural defect and almost always the landlord's responsibility. It will not improve on its own.

Rising damp

Less common, but serious. Water travels up through masonry from the ground — usually because the damp-proof course has failed or was never installed. Signs include a tide mark at low level (typically below one metre), peeling wallpaper or plaster at skirting level, and a distinctive salt crystallisation on the wall surface.

Rising damp is expensive to fix properly and landlords sometimes dispute the diagnosis. Getting an independent assessment of what you are seeing gives you a solid starting point before you report it.

Why it matters for your health

Mould produces spores that, with prolonged exposure, can cause or worsen respiratory conditions — particularly in children, older people, and anyone with asthma or a compromised immune system. The link between damp housing and poor health is well established in the medical literature, and it is the reason the law has recently changed.

What your landlord is now legally required to do

Under Awaab's Law (now extended to the private rented sector under the Renters' Rights Act 2025), once you formally notify your landlord of a damp or mould problem they must:

• Investigate within 14 days
• Begin emergency repairs within 7 days if the hazard is confirmed as serious
• Complete repairs within a reasonable timeframe, documented in writing

The abolition of Section 21 "no-fault" evictions — also part of the Renters' Rights Act — means your landlord can no longer serve you notice simply because you complained. That particular threat has been removed from the equation.

How to report it — and why evidence matters

The formal notification that starts your landlord's legal clock is a written report — an email is fine. Keep a copy. Before you send it, photograph everything you can see: the mould patches, any water staining, any structural damage. The timestamp on those photographs is evidence that the problem existed before any dispute arose.

Describe what you are seeing clearly and specifically. "There is mould in the bathroom" is less useful than "there is black mould covering approximately half of the external wall in the bathroom, concentrated around the window frame and extending to the ceiling. It has been present and growing since at least January." If you are not sure what type of damp it is or how serious it might be, find that out before you write the letter — it will make your report much harder to dismiss.

If your landlord does not respond

After the 14-day investigation window has passed without a response, you have options:

• Your local council's environmental health team can inspect the property and issue improvement notices or prohibition orders. This is free and does not require a solicitor.
• The Private Rented Sector Ombudsman (mandatory from May 2026) gives you a free, independent complaints route without going to court.
• Shelter and Citizens Advice both offer free housing advice and can help you understand your specific situation.

The most important thing is to start the paper trail. A problem you have documented and reported formally is one you can escalate. A problem you have only ever mentioned verbally is much harder to pursue.