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The whole house

What to dry, clean and throw out after a flood

The recovery pages give the same first instruction for a flooded home: dry it out as fast as it can be done, because the window is short. Victoria’s health department puts it at 48 hours, Tasmania’s at 24 to 48, and WA Health’s guidelines report international agencies’ advice that mould can take hold within 24 to 48 hours in a flooded home that stays very wet. This page keeps their order, then sorts the materials into what dries, what is cleaned, and what goes.

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 Staying healthy during and after flood, from NSW Health.

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. FloorSee the house

Before you go back in

Two pages do the work this one cannot do in its own words: the safety checks for going back into a flooded home. Victoria’s health department keeps the page for that step, Returning home after a flood, and it opens by saying to read it, so you and your family can avoid injury or illness.

For emergency flood or storm assistance in Victoria, the number on the Victorian health department’s flood page is 132 500. The same page’s own order of work is to have the hazards checked first, by the trades that certify them: a qualified electrician or plumber confirms the gas and electricity supply is safe, and a qualified building surveyor declares the structure safe.

In the order the recovery pages give

  1. First, the drying

    NSW Health’s instruction is to start drying out the house as soon as floodwaters recede, keeping all doors and windows open on dry days and using fans to help, draining the water that sits under the house to improve the airflow, and checking the wall or floor cavities for trapped water or mud. WA Health’s clean-up page gives the same list as steps: doors and windows open on dry days, fans helping the air move, water drained from under the house, and a check for trapped water and mud in the walls and floors. SA Health says the same thing at speed: open all the doors and windows, and use fans if possible.

    The 24 to 48 hours are the whole reason for the hurry. Tasmania’s health department says the clean-up and dry-out should happen within that window to prevent the mould spreading, and WA Health’s guidelines report international agencies’ advice that mould can take hold within the same 24 to 48 hours in a flooded home that stays very wet, and that a home not cleaned and dried within 48 hours is likely to have mould contamination already.

  2. Next, what to wear

    Every recovery page dresses the cleaner before it describes the cleaning. NSW Health asks for protective clothing including boots, gloves and eye protection, solid shoes rather than thongs or sandals, and gloves whenever flood-affected items or mud are handled; it also says to keep children out of flood-affected areas. SA Health lists sturdy footwear such as rubber boots, loose long-sleeved shirts and trousers, thick waterproof gloves, a hat and eye protection. WA Health’s clean-up page asks for rubber boots and waterproof gloves, a facemask or goggles where scrubbing, hosing or pressure-washing is going on, and waterproof dressings over any open cuts, scratches or grazes; it also says to keep children and pets away from the building until it is clean and safe again. Victoria’s health department shortens it to sturdy waterproof boots and rubber or leather gloves.

  3. Then, assume the mould is there

    Victoria’s health department says to assume a home is contaminated with mould when the flood water stood for longer than two days, when mould can be seen, when there is water damage, or when the smell is strongly musty. Tasmania’s health department assumes contamination where the building was flooded for more than two days, or where there is visible water damage or musty odours afterwards. WA Health’s indoor mould guidance goes further for flood water: once flood water has affected an indoor space for more than 24 to 48 hours, anyone going in should assume extensive growth and the risk of complex mould, with protection in line with complex remediation.

    From there the work is subtraction. NSW Health says to remove all wet items where possible, naming floor coverings, rugs, mats, furniture, bedding, linen and clothing, and that where floor coverings come up, the floor underneath is cleaned and dried thoroughly before new material is laid. Victoria’s health department names the wet items, among them wallpaper and plasterboard, carpet and rugs, bedding, mattresses, furniture, stuffed toys and clothing, and says each has to come out where it cannot be properly dried or cleaned. The Queensland building commission’s timber guide warns that in houses built after about the mid 1970s the wall lining may also be the wall bracing, so where it is stripped temporary diagonal timber braces should be nailed to each wall until permanent bracing and lining go back.

  4. Later, the reconstruction clock

    The drying continues past the first week, and the pages put dates on the repairs that follow it. The Queensland building commission’s guide asks for a minimum of four months before a timber floor is re-assessed, and a concrete slab left a minimum of three months to dry once the flooring is up and the slab cleaned. The Better Health Channel’s flood page asks for repainting and redecorating to be left for at least three months, until the house has thoroughly dried out, because paint and paper put on too early can bring mould, blistering and peeling with them, and vinyl flooring laid too early can also hold moisture in.

    Two more things change after flood water has been through a building. WA Health’s guidelines say a flood-damaged building closed up for several days should be entered briefly to open doors and windows and ventilated for at least 30 minutes before anyone stays inside. And the Queensland guide says a flood can compromise the termite management system that protects the building, which is a licensed pest controller’s inspection to reinstate.

Dry, clean or throw out

The choice is per material, and the pages do not agree on every item. Each cell names the page its lines come from, and the source column names the same page again in short.

What the recovery pages say, by material
MaterialWhat the pages saySource
Carpet and underlayNSW Health’s instruction is to clean and dry water-damaged carpets and building materials completely, and to discard anything that cannot be cleaned and dried completely. Victoria’s health department lists carpet and rugs among the wet, flood-damaged items to remove from the home with the rest. NSW Health; Victorian Department of Health.
PlasterboardVictoria’s health department and WA Health both say the same thing about wet wall lining: remove the plasterboard so the internal wall space can dry out properly. The Queensland building commission’s timber guide adds that most lining products that were inundated, plasterboard among them, need to be replaced, and that lining should come off to at least 300 mm above the highest level the water reached. In houses built after about the mid 1970s the lining may also be the wall bracing, so where it is stripped the guide says temporary diagonal timber braces should be nailed to each wall until permanent bracing and lining go back. Victorian Department of Health; WA Department of Health; Queensland Building and Construction Commission.
Timber floors and framingThe Queensland building commission’s guide treats timber as its own material. Frames that were under water should be washed down and dried as quickly as possible; the space under a suspended floor has to be drained and dried out immediately; and how long a fully saturated piece of timber takes to dry depends on its thickness, density and the ventilation it gets. Flooring needs a longer view: the guide asks for a minimum of four months before re-assessing a timber floor, and a concrete slab that has been cleaned should be left a minimum of three months to dry. Queensland Building and Construction Commission.
Mattresses and soft furnishingsNSW Health says flood-affected mattresses are difficult to treat and may need to be discarded, while a foam rubber mattress can be washed with a garden hose and have a detergent solution squeezed through it before it dries. Other mattresses, or lounge furniture, may be air-dried in the sun and then sprayed with a disinfectant solution. WA Health’s version separates inner spring from foam: an inner spring mattress is hard to treat and may have to be thrown out. Victoria’s health department puts mattresses, stuffed toys and clothing in the list of wet items that cannot be properly dried or cleaned, and SA Health says absorbent household materials such as mattresses and upholstered furniture should be removed and discarded, because they are difficult to disinfect and dry and can become mouldy. NSW Health; WA Health; Victorian Department of Health; SA Health.
Hard surfacesNSW Health’s method for hard-surfaced floors, walls, benches and sinks is hot soapy water first and then a disinfecting wipe or spray with a chlorine bleach solution or a product labelled as a disinfectant. For its 10 litre bucket of disinfectant, the page’s instruction is to put gloves on, fill the bucket with water, and then add 50 mL of 4% chlorine household bleach. SA Health cleans with detergent and water first and then disinfects walls, floors and ceilings with a different dilution: 125 mL of household bleach in 5 L of clean water, and it says not to use hot water. WA Health’s clean-up guidance for householders is hot soapy water then a chlorine bleach solution or a labelled disinfectant, left to dry once disinfected. NSW Health; SA Health; HealthyWA (WA Health).

Not everything in a flooded room is a decision. HealthyWA’s advice for houses after a flood is that any medicine touched by floodwater should be thrown out, and NSW Health’s rule for toys does the same by shape: soft toys, and moulded plastic toys with air injection holes, should be discarded, while solid toys can be washed and disinfected.

Timber floors and framing

The Queensland building commission’s guide to flood-damaged timber follows timber through the whole job, in one order: clean the timber of silt and mud as soon as the water has receded, then let it dry as quickly as possible with good ventilation, using fans, air conditioners or dehumidifiers where the power is back on. The space under a suspended floor is drained and dried out at the same time, with the ventilation points cleared of debris and blowers used where they are needed.

What happens next depends on the timber. Left damp with air available, the guide says, mould (dark staining) can set in and decay can follow over time, particularly in low-durability timbers such as untreated pine. Its test is the knife: a surface stain that scrapes off to sound timber underneath is not of concern, while wood that has become soft and spongy, or that a knife or screwdriver penetrates easily, has degraded. On treatment, the guide carries one prohibition that matters after a flood: do not use chlorine pool products on it, because of the corrosion they can cause to metal connectors and fasteners. Higher-density timber such as hardwood takes longer to dry than softwood, and the guide points to moisture meters as the way to assess how wet a piece of timber is.

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