Minimising the risk of mould in your property - Landlords bulletin 69

This publication is for: 
Landlord / lessor

23 June 2023

Minimising the risk of mould in your property

Mould or dampness can pose a serious health risk, as well as cause structural damage to your rental property. The risk of mould increases during wet or humid weather, and after major storms, but there are ways to stop mould from developing in your investment property.

Mould produces tiny particles called spores that are carried in the air. Spores may cause health problems such as breathing difficulties, wheezing, asthma, sinus problems, rashes and watery, itchy or red eyes. If you have asthma, inhaling mould can cause more attacks.

Some people may develop a severe mould infection, usually in their lungs, and will need to see a doctor to manage the condition. People most at risk include older people, babies and children, and people with a respiratory illness or weakened immune system.

You should be able to detect mould during routine inspections. Mould lets off a musty odour, and you can see it growing on ceilings and walls, in cupboards, and along grout between tiles. It starts off as small black dots that spread quickly.

It also grows in wall and roof cavities, and can cause discoloured and bulging patches that may be cold or damp to touch.

Reducing the risk of and treating mould requires a joint effort, and both you and your tenants have responsibilities under tenancy laws.

Tenants’ responsibility

Your tenant is only responsible for mould that they have caused, such as not using provided, working exhaust fans in bathrooms and kitchens, leaving surfaces wet for a long time, not ventilating the property, or not keeping their home in a reasonable state of cleanliness.

Your responsibility

You should make sure there is no mould in your property before you rent it out. You are required to provide a safe and clean environment for tenants.

While your property is rented, you could be in breach of a rental agreement if mould develops due to a lack of maintenance or repairs.

To avoid mould developing, you should:

  • check for any signs of moisture inside your property or structural damage during routine inspections
  • restrict moisture entering the property from leaks in the roof or floors, through structural faults such as cracks in walls, unsealed windows, or faulty plumbing
  • provide adequate exhaust fans in all areas where moisture is produced, such as bathrooms, kitchens and laundries
  • make sure windows are in good working order and can be securely left open
  • clean and maintain gutters so rainwater does not leak into the roof cavity

You must make sure your property complies with all requirements of tenancy laws, as well as building and health regulations. You cannot ask your tenant to pay for treating or removing mould caused by a structural issue, or if you have not provided adequate ventilation options or exhaust fans.

If your tenant develops long-term health problems as a result of mould or if mould causes damage to your tenants’ belongings, they can apply to the courts for compensation.

Getting rid of mould – cleaning tip

Mould should be removed as soon as it appears as it is likely to return unless you also take steps to treat the cause of the problem.

To remove small patches of mould, the Health Department recommends you scrub mould off hard surfaces using soapy water. The physical action of scrubbing is important as the mould must be physically removed to prevent regrowth.

Clean up any mould residue caused by the scrubbing with a damp cloth or vacuum cleaner with a HEPA filter. Dry the area, and find and fix the source of the moisture.

Other products that can be used to treat small mould patches include domestic mould remover that is sold in supermarkets or natural anti-fungal agents such as vinegar, tea-tree oil or clove oil.

Products that are developed to treat mould outdoors, including around swimming pools or spas, should not be used to treat mould inside your property.

If the mould covers a large area, or keeps coming back, it should be treated by a mould removal professional.

More information about mould and tips on how to treat it can be found on the HealthyWA website.

Consumer Protection
Last updated 23 Jun 2023

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