Mould in Your Rental: Who's Responsible and What to Do

Australian tenancy law in every state holds that the party responsible for the cause of the mould is responsible for fixing it.

If the mould is caused by a structural problem — a leaking roof or wall, inadequate ventilation built into the property, rising damp, blocked gutters, or a plumbing fault — that is the landlord's responsibility to fix. These are maintenance issues that fall squarely within the landlord's obligation to keep the property in good repair.

If the mould is caused by lifestyle factors — consistently failing to ventilate a bathroom with no exhaust fan, drying laundry inside in an enclosed space without opening windows — a landlord may argue the tenant bears responsibility. In practice, most mould problems have a structural component, and tenants should not accept sole blame without evidence.

Prolonged exposure to mould can cause or worsen respiratory conditions, trigger allergic reactions, and in severe cases cause more serious health complications — particularly for children, the elderly, and people with asthma or compromised immune systems.

This is why mould in living areas, bedrooms, or anywhere that affects the liveability of the property is generally treated as an urgent repair under tenancy legislation — not a non-urgent nuisance to be eventually addressed.

As soon as you discover mould, photograph it thoroughly. Note the location, the approximate size, and any nearby features that suggest a cause — a damp wall near a window, water staining on the ceiling, condensation on a wall that should not have any.

If you have noticed related issues — a window that leaks when it rains, slow drainage, a musty smell that was there when you moved in — note those too. Building a picture of the potential cause strengthens your position when you report it.

Report the mould to your landlord or property manager in writing — email is ideal. Include your photographs and describe where it is, how large the affected area is, and any relevant context about potential causes.

Ask for an inspection and a remediation plan, and specify a response deadline. For significant mould in a living or sleeping area, seven days is reasonable. Keep a copy of everything.

The written notification starts the clock on the landlord's obligation to respond. If they later claim they were not aware of the problem, your written record proves otherwise.

If you receive no meaningful response — or the landlord disputes responsibility without investigation — your next step depends on the severity.

For urgent mould situations (large affected areas, health impact, structural water ingress), most states allow tenants to arrange emergency remediation themselves and claim the cost back from the landlord, up to a legislated limit. Check your state's rules before doing this.

For non-urgent situations where the landlord is simply slow or dismissive, send a follow-up in writing with a final deadline and a clear statement that you will apply to the tenancy tribunal if the matter is not resolved. Many landlords respond when the alternative becomes concrete.

If escalation is needed, apply to your state tenancy tribunal for a repair order. Bring your written requests, photos, and any documentation of the health impact. The tribunal can order the landlord to carry out specific remediation by a set date.

In severe cases — extensive black mould throughout the property, structural damp that the landlord refuses to address, or mould that has caused documented health problems — the property may be considered unfit for habitation. This is a high threshold, but it does exist.

If you reach this point, contact your state tenancy authority or a community legal centre before taking action. Depending on the circumstances, you may have grounds to terminate the tenancy without penalty and potentially claim compensation for damaged belongings or health impacts.

Document your ventilation habits from the start. If you run the bathroom exhaust fan after showers, open windows regularly, and avoid drying clothes indoors — and the mould still appears — that is relevant evidence that the cause is structural rather than behavioural.

If the mould was present when you moved in and was noted on your ingoing condition report, the landlord cannot claim it was caused during your tenancy. If it was not noted but was clearly pre-existing, photograph the evidence immediately and report it. The longer you wait, the harder it becomes to establish that the mould predates your tenancy.