My landlord says black mould is my fault, is it?

The question of who is responsible for damp and mould depends on the cause. There are broadly three types: rising damp (comes up from the ground — always a structural issue and the landlord's responsibility), penetrating damp (water coming through walls or roof — structural and the landlord's responsibility), and condensation (caused when moisture in the air meets cold surfaces).

Condensation is the most commonly disputed type. While poor ventilation or tenant behaviour can contribute, the underlying cause is often inadequate insulation, poor heating, or structural problems — all of which are the landlord's responsibility. The Homes (Fitness for Human Habitation) Act 2018 specifically includes "excessive damp" and "inadequate ventilation" as hazards that can make a property unfit for habitation.

The Housing Health and Safety Rating System (HHSRS), administered by local councils, rates damp and mould as a Category 1 (most serious) hazard in many cases. If your property is affected, you can ask your local council to carry out a free HHSRS inspection. If they identify a hazard, they can require your landlord to carry out works.

A landlord who simply blames the tenant without investigating the cause is likely in breach of their obligations. Write to your landlord formally, provide photographs, and ask them to inspect and confirm the cause. If they do not act, contact the council and consider a civil claim under the Homes Act.

Mould can be a serious health hazard, particularly for children and people with respiratory conditions. You should act quickly and keep detailed records.