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The whole house

Can I clean mould myself?

The health pages allow a person to clean a small patch of mould at home, and every one of them asks for the surface to be dried afterwards. They part company on the details, which is what the table below puts side by side: the size, the mixture, the protective kit, and who should stay out of the room.

General information from official health, building and housing sources, not advice about your home, your health or your tenancy. The page behind most of this one is NSW Health’s mould factsheet.

Water from a leaking roof, reaching the ceiling: NSW Health lists a leaking roof and a blocked rain gutter among the water leaks and plumbing problems to repair.Water from a gutter fault, into the top of the outside wall: Consumer Protection WA’s list of what a landlord should do to avoid mould developing includes cleaning and maintaining the gutters, so rainwater stays out of the roof cavity.Where a roof or ceiling leak shows: NSW Fair Trading’s own inspection list says to check for damp or mould along skirting boards, walls and ceilings.Where a gutter fault shows: a discoloured or bulging patch that may be cold or damp to touch, in the wall or roof cavity (Consumer Protection WA). Shower steam, and the bathroom exhaust fan the building code sizes: the 2025 National Construction Code sets a minimum exhaust flow rate, 25 litres a second for a bathroom or sanitary compartment.Signs in a wet area: the SA Government’s inspection list says to look for mouldy walls, lifting tiles, peeling paint or pools of water. Moist air reaching cold window glass: the national home design guide says condensation forms when humid air meets a cooler surface, such as a window in winter.Condensation and mould on the window: the national home design guide says aluminium frames form a thermal bridge into the home and are prone to condensation.Moist air reaching the outside wall behind a wardrobe: one of Homes Tasmania’s tips for a dry, well-aired home is to allow space between furniture and the wall so air can flow, and it calls this very important with wardrobes.Mould on the outside wall behind the wardrobe: one of Homes Tasmania’s tips is not to stack boxes or other items against outside walls, especially walls that do not get a lot of sun.A small patch on a bedroom wall: NSW Health says it is good to remove mould as soon as it appears. Water from a concealed pipe leak, down inside the wall: SA Water says damp, warped or discoloured walls, floors or carpets can suggest a concealed leak indoors.Where a concealed leak shows: Icon Water says to look in the kitchen, bathrooms and laundry for dripping taps, washing machine and dishwasher connections, and damp patches on the walls. Flood water in the home (the line marks no depth): Victoria’s health department says flooding can cause excessive mould growth, which has to be cleaned up before moving back in.A floor joist with staining or decay: the Queensland timber guide says a surface stain that scrapes off to sound timber underneath is not of concern, while wood that is soft and spongy or easily penetrated has decayed. Damp rising from the ground into the base of the wall: NSW Health says rising damp is ground moisture rising up a brick or stone wall.Where rising damp shows: the base of the wall and the skirting, where Consumer Affairs Victoria says damp brick walls can indicate rising damp or salt damp.Damp ground under the floor: Homes NSW says rising damp is moisture from the ground travelling up into a home through the bricks or stone in its walls.A damp subfloor: NSW Fair Trading’s inspection list says to lift carpet and check for rotting floorboards or damp. Water from a leaking roof, reaching the ceiling: NSW Health lists a leaking roof and a blocked rain gutter among the water leaks and plumbing problems to repair.Where a roof or ceiling leak shows: NSW Fair Trading’s own inspection list says to check for damp or mould along skirting boards, walls and ceilings.Water from a gutter fault, into the top of the outside wall: Consumer Protection WA’s list of what a landlord should do to avoid mould developing includes cleaning and maintaining the gutters, so rainwater stays out of the roof cavity.Where a gutter fault shows: a discoloured or bulging patch that may be cold or damp to touch, in the wall or roof cavity (Consumer Protection WA). Shower steam, and the bathroom exhaust fan the building code sizes: the 2025 National Construction Code sets a minimum exhaust flow rate, 25 litres a second for a bathroom or sanitary compartment.Signs in a wet area: the SA Government’s inspection list says to look for mouldy walls, lifting tiles, peeling paint or pools of water. Moist air reaching cold window glass: the national home design guide says condensation forms when humid air meets a cooler surface, such as a window in winter.Condensation and mould on the window: the national home design guide says aluminium frames form a thermal bridge into the home and are prone to condensation.Moist air reaching the outside wall behind a wardrobe: one of Homes Tasmania’s tips for a dry, well-aired home is to allow space between furniture and the wall so air can flow, and it calls this very important with wardrobes.Mould on the outside wall behind the wardrobe: one of Homes Tasmania’s tips is not to stack boxes or other items against outside walls, especially walls that do not get a lot of sun.A small patch on a bedroom wall: NSW Health says it is good to remove mould as soon as it appears. Water from a concealed pipe leak, down inside the wall: SA Water says damp, warped or discoloured walls, floors or carpets can suggest a concealed leak indoors.Where a concealed leak shows: Icon Water says to look in the kitchen, bathrooms and laundry for dripping taps, washing machine and dishwasher connections, and damp patches on the walls. Flood water in the home (the line marks no depth): Victoria’s health department says flooding can cause excessive mould growth, which has to be cleaned up before moving back in.A floor joist with staining or decay: the Queensland timber guide says a surface stain that scrapes off to sound timber underneath is not of concern, while wood that is soft and spongy or easily penetrated has decayed. Damp rising from the ground into the base of the wall: NSW Health says rising damp is ground moisture rising up a brick or stone wall.Where rising damp shows: the base of the wall and the skirting, where Consumer Affairs Victoria says damp brick walls can indicate rising damp or salt damp.Damp ground under the floor: Homes NSW says rising damp is moisture from the ground travelling up into a home through the bricks or stone in its walls.A damp subfloor: NSW Fair Trading’s inspection list says to lift carpet and check for rotting floorboards or damp. Bedroom wall and wardrobeSee the house

How big is the patch?

Water from a leaking roof, reaching the ceiling: NSW Health lists a leaking roof and a blocked rain gutter among the water leaks and plumbing problems to repair.Water from a gutter fault, into the top of the outside wall: Consumer Protection WA’s list of what a landlord should do to avoid mould developing includes cleaning and maintaining the gutters, so rainwater stays out of the roof cavity.Where a roof or ceiling leak shows: NSW Fair Trading’s own inspection list says to check for damp or mould along skirting boards, walls and ceilings.Where a gutter fault shows: a discoloured or bulging patch that may be cold or damp to touch, in the wall or roof cavity (Consumer Protection WA). Shower steam, and the bathroom exhaust fan the building code sizes: the 2025 National Construction Code sets a minimum exhaust flow rate, 25 litres a second for a bathroom or sanitary compartment.Signs in a wet area: the SA Government’s inspection list says to look for mouldy walls, lifting tiles, peeling paint or pools of water. Moist air reaching cold window glass: the national home design guide says condensation forms when humid air meets a cooler surface, such as a window in winter.Condensation and mould on the window: the national home design guide says aluminium frames form a thermal bridge into the home and are prone to condensation.Moist air reaching the outside wall behind a wardrobe: one of Homes Tasmania’s tips for a dry, well-aired home is to allow space between furniture and the wall so air can flow, and it calls this very important with wardrobes.Mould on the outside wall behind the wardrobe: one of Homes Tasmania’s tips is not to stack boxes or other items against outside walls, especially walls that do not get a lot of sun.A small patch on a bedroom wall: NSW Health says it is good to remove mould as soon as it appears.The area a health page gives as the limit for cleaning it yourself: WA Health defines simple mould contamination in part by size, no greater than one square metre. Water from a concealed pipe leak, down inside the wall: SA Water says damp, warped or discoloured walls, floors or carpets can suggest a concealed leak indoors.Where a concealed leak shows: Icon Water says to look in the kitchen, bathrooms and laundry for dripping taps, washing machine and dishwasher connections, and damp patches on the walls. Flood water in the home (the line marks no depth): Victoria’s health department says flooding can cause excessive mould growth, which has to be cleaned up before moving back in.A floor joist with staining or decay: the Queensland timber guide says a surface stain that scrapes off to sound timber underneath is not of concern, while wood that is soft and spongy or easily penetrated has decayed. Damp rising from the ground into the base of the wall: NSW Health says rising damp is ground moisture rising up a brick or stone wall.Where rising damp shows: the base of the wall and the skirting, where Consumer Affairs Victoria says damp brick walls can indicate rising damp or salt damp.Damp ground under the floor: Homes NSW says rising damp is moisture from the ground travelling up into a home through the bricks or stone in its walls.A damp subfloor: NSW Fair Trading’s inspection list says to lift carpet and check for rotting floorboards or damp.
The dashed square is the one figure the health pages put on a patch you clean yourself: WA Health’s guidelines call mould contamination no greater than one square metre simple, and anything larger complex.

Only one of the health pages here puts a number on a patch a person can clean themselves. WA Health’s guidelines for managing mould define a simple mould problem in part by size, contamination no greater than one square metre, and call a problem complex when it is larger than that or is found in more than one room. The same guidelines are careful about their own figure: they call it a recommendation drawn from United States and World Health Organization advice, not a health threshold, and they say a larger area may still be remediated without professional help.

The other pages leave the judgement to the reader. Victoria’s health department draws the line at small to medium sized areas, Tasmania says small areas can be cleaned, and NSW Health gives no size at all: it says to clean the patch as soon as it appears and to expect some effort.

The state health pages, side by side

The four columns hold what each page says about the same four questions. Where a page does not answer one, the cell says so rather than filling the gap.

Cleaning a small patch of mould, by state health page
StateSize limitWhat to wearHow to cleanWho should not
New South WalesNo figure. The factsheet gives a method for a small patch and says it is good to remove mould as soon as it appears. PVC or nitrate rubber gloves, safety glasses and safety shoes when bleach is used, in a well-aired area. Mild detergent or vinegar diluted in water, four parts vinegar to one part water, for routine clean-up. Where the mould is not readily removed and the item cannot be discarded, 250 mL of bleach in 4 litres of water, then the surface dried completely. No source here says.
VictoriaSmall to medium sized areas may be removed at home; the page gives no figure. Good ventilation, plus protective clothing: a P1 or P2 mask, eye protection, gloves, overalls, closed footwear and a shower cap are the items its removal page lists. For many jobs, household detergent or white vinegar is enough, worked over with a microfibre cloth that is rinsed often in a separate bucket of clean water; the cleaner is left to work before it is mopped or sponged up, the area is not left too wet, and it is dried afterwards. Pregnant women and children, and anyone with a weakened immune system or a chronic lung disease.
Australian Capital TerritoryNo figure. The page says to clean mould as soon as it appears, and gives the routine mixture for a small patch. PVC or nitrate rubber gloves, safety glasses and safety shoes when bleach is used, with the area well aired. Mild detergent or vinegar diluted in water, four parts vinegar to one part water. Where the mould is not readily removed and the item cannot be discarded, the same bleach figure as NSW: 250 mL of bleach in 4 litres of water. The surface is dried completely once cleaned. No source here says.
Western AustraliaOne square metre is its mark between a simple and a complex problem, and the guidelines call the figure a recommendation, based on United States and World Health Organization advice rather than a health threshold; an area larger than that may still be handled without professional help. When removing mould, WA Health’s page says to put on personal protective equipment: rubber gloves, a face mask and safety goggles. It adds the room’s condition to the same instruction: keep it well ventilated, but without the strong air movement that would carry the spores into other parts of the home. Scrub the mould off the hard surface with soapy water, working the scrub up to 50 cm past the edge of the visible mould. Soapy water is usually enough on its own, and the other products its page lists are commercial ones and natural anti-fungal agents such as vinegar and tea-tree oil; the residue the scrubbing loosens is lifted with a damp cloth or a vacuum with a HEPA filter before the area is dried. Susceptible people may need to leave the area while the work is done.
TasmaniaSmall areas of mould can be cleaned; the page gives no figure. Rubber gloves, safety glasses and a face mask, with the area well ventilated. A mild detergent or a mixture of four parts vinegar to one part water. Where the mould is not readily removed, one part bleach to three parts water. It warns against dry-brushing, which disperses spores into the air and can establish growth elsewhere. Children under 12, pregnant women, people over 65, people with allergies or with breathing conditions like asthma, and people whose immune systems are weakened, for example by HIV infection or chemotherapy, should avoid the clean-up and avoid being in the room while it is done.

Where they agree, and where they differ

  • They agree on the routine mixture. NSW Health, the ACT and Tasmania all start with four parts vinegar to one part water, Victoria’s page says household detergent or white vinegar is enough in many cases, and Western Australia’s puts soapy water first.
  • They agree on finishing the job dry. NSW Health and the ACT each end with the surface dried completely once it has been cleaned; Western Australia’s page ends with drying the area, and Victoria’s with drying afterwards where possible.
  • Bleach is where they part. NSW Health and the ACT both use 250 mL of bleach in 4 litres of water for mould that will not come off; Tasmania uses one part bleach to three parts water; Victoria’s removal steps work with detergent or white vinegar, and the bleach on its page appears in a safety warning about what never to mix with it.
  • WA Health’s guidelines put a limit on what bleach achieves at all: bleach products can reduce mould growth on a treated surface but they do not seem to work well against regrowth over the longer term, and on their own they will not completely remove mould from infested building materials.
  • The room has to be aired while the work is done, and Western Australia’s guidance goes further than the others: its working area is to be ventilated with fresh air from open windows, and fans and exhaust fans are to stay off while the mould is being cleaned, so the spores are not carried into other rooms.

Cleaning mould, step by step

One page gives the job in an order, and it is Western Australia’s: scrub, lift, dry, and fix the water. The steps below follow it.

  1. Scrub

    Scrub the mould off the hard surface with soapy water, working up to 50 cm past the visible edge of the mould, because new growth can sit there unseen by the naked eye.

  2. Lift what the scrubbing loosens

    Wipe the loosened mould residue away with a damp cloth, or vacuum it up with a vacuum that carries a HEPA filter; Victoria’s health department adds that a HEPA filter is the only kind of vacuum to use on a mould-affected area, because other cleaners put the fine particles back into the air.

  3. Dry the surface

    Dry the area, allow it the days that drying takes, and hold off painting, sealing or covering the surface until it is dry. On drying, WA Health’s guidelines say the air temperature should be ambient, not hot, because hot air can dry the outer layer and leave the moisture trapped inside.

  4. Fix the water

    Find and fix the source of the moisture. The same guidelines say fixing the source has to happen at the same time as the cleaning, or the mould simply returns.

  5. What not to keep

    Some things are for the bin rather than the cloth. Victoria’s removal page lists cardboard boxes and mattresses among the mouldy items that cannot be cleaned, and says items that have been mouldy for several weeks, bedding among them, may not come clean at all. Soft fabric articles such as soft toys can be washed in a machine on a hot cycle, and cleaning clothes are washed separately from the rest. NSW Health adds that absorbent material such as carpet may need professional cleaning, or replacement. Tasmania’s page is blunter about absorbent materials: carpets, upholstery and mattresses that are contaminated need to be discarded.

Timber is different

Timber that has been wet is its own case, and the Queensland building commission’s guide to flood-damaged timber handles it separately from plaster and tile: it says chlorine pool products should be avoided for treating and preventing mould because of the corrosion they can cause to metal connectors and fasteners. The guide’s test for a stained joist is the knife: a surface stain that scrapes off to sound timber underneath is not a concern, while wood that has gone soft and spongy, or is easily penetrated, has decayed.

Mould and health

NSW Health’s own factsheet carries the health side as general information. It says most people will not experience any health problems from coming into contact with mould, and that where there are effects they include a runny or blocked nose, irritation of the eyes and skin, and sometimes wheezing; for people with asthma, inhaling mould spores may cause an asthma attack. People with asthma, allergies or other breathing conditions may be more sensitive to mould, and anyone with a weakened immune system, or a chronic lung disease, is more at risk of a mould infection, particularly in the lungs.

If mould is affecting someone’s health, the health page sets out what to do: Mould, from NSW Health.

If the building might contain asbestos

For sheeting that may contain it, the Queensland building commission’s guide to flood-damaged timber gives this advice, and names the trade: do not sand or cut those products, and leave their removal and disposal to a specially licensed (Class B) contractor. The federal safety agency’s advice for householders is plain: it is not recommended that you handle or remove asbestos yourself, and in some places the law goes further: in the Australian Capital Territory any removal needs a licensed removalist, unless it is part of minor routine maintenance or other minor work, and in Queensland only a removalist holding a Class A licence may remove friable material. The agency adds that a professional is easier, safer and often cheaper, and that the waste has to be disposed of at a landfill that is licensed to take it.

Now find the water

A cleaned patch lasts as long as the moisture that fed it is still arriving. NSW Health’s answer is on the same page as its cleaning method: the mould is likely to return unless steps are taken to treat the cause of the problem. Victoria’s health department puts the same point at the top of its removal page, which is why the next step is to find where the water is coming from.

Is it a leak, rising damp or a roof problem?

Why does mould keep coming back in the bathroom and wardrobe?