Is black mould on a bedroom wall dangerous, and who removes it?

Why is mould in a bedroom more of a concern than mould elsewhere?

A bedroom is usually the room where someone spends the most consecutive hours in a house, asleep with reduced ventilation compared to daytime, often with a door closed and sometimes with furniture pushed against the affected wall, which traps air and moisture further. Spores released from mould growth are more likely to be breathed in over a long, close, unbroken stretch of time in a bedroom than in a hallway or utility room someone passes through briefly.

What symptoms suggest mould exposure rather than something else?

Persistent coughing, wheezing, sinus congestion or irritated eyes that improve when you are away from the room, and worsen again when you return, are a common pattern people report. These symptoms are not unique to mould and can have other causes, so anyone with ongoing or worsening symptoms should speak to a GP, particularly if they have asthma or a respiratory condition. Mould exposure is one possible factor to mention, not a self-diagnosis to rely on alone.

Does the size of the mould patch tell you how serious it is?

Not reliably. A small, contained patch on a cold spot behind a wardrobe can be a straightforward condensation problem that clears once ventilation improves. A patch that keeps returning despite cleaning, spreads across a wall, or appears alongside a musty smell or a damp patch often points to a moisture source behind the surface, such as a leak or penetrating damp, which will keep feeding the mould regardless of how many times it is wiped away.

Who is responsible for removing mould, the tenant or the landlord?

If you own the property, removing mould and fixing the moisture cause is your responsibility. If you rent, landlords have a legal duty to investigate and address damp and mould that makes a home unfit to live in, particularly under the timescales introduced by Awaab’s Law, and cleaning products alone are not considered a proper fix if the cause is a building fault rather than everyday condensation. Tenants should report mould in writing and keep a record, rather than treating it themselves indefinitely and hoping it does not return.

Should I just clean it myself, or call someone in?

Cleaning a small, surface patch with a proper mould treatment, not bleach alone, which often only lightens the colour rather than killing the growth, is reasonable as a first step for a small area with an obvious cause, such as a wardrobe pushed against an external wall with no ventilation gap. If it keeps coming back, spreads, or you cannot identify an obvious cause like poor ventilation, that is the point to bring in someone to diagnose the actual source rather than repeating a clean that will not hold.

Who should I call to remove mould properly and stop it coming back?

A mould treatment that only removes the growth without addressing what is feeding it usually sees the mould return within weeks. Mould treatment from Damp & Mould Solutions UK is based on identifying the moisture source behind the wall before treating it, rather than a surface clean alone. Full mould remediation details set out what that involves.

Related: mould inspection service and black mould in the bathroom.

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