Drying out a house after a flood

Drying out is the slow part of recovering from a flood, and it matters: repairs done before the walls and floors are dry can trap moisture and fail. Here's how it works, how long it can take and what helps.

Before you start

• Gas and electrics first. GOV.UK says to get your utilities company or a qualified engineer to check they're safe before turning them back on. The UK Health Security Agency adds that gas or oil central heating should be checked by a qualified engineer before you use it to dry the house. Natural Resources Wales says not to turn on electricity, gas or water without professional advice.
• If you're insured, call your insurer before you start. The Association of British Insurers (ABI) says your loss adjuster will organise the cleaning and stripping out, and that this should start within four weeks of discussing it with them.
• Don't throw things away yet. The ABI says to talk to your insurer about what to do with damaged items.

How long it takes

Longer than most people expect.

• The ABI says professional drying can take a few weeks to several months, and that moving back home can be between a few weeks and a year or more after the flood, depending on the damage.
• NI Direct says drying out can take weeks or months, depending on things like how serious the flooding was and what the house is built from.
• Government guidance on drying flood-damaged buildings, from 2010, put a realistic target at 4 to 8 weeks to dry a home ready for repair. It's old, but it shows why drying can't be rushed.

Airing and drying

• Heat, dehumidify and ventilate. UKHSA says heating, dehumidifiers and good ventilation can help to dry out your home, and suggests keeping the thermostat at 20°C to 22°C for steady drying.
• Windows open or shut, depending on the kit. Natural Resources Wales says to keep doors and windows open to dry the house, or to use a dehumidifier with them closed. NI Direct also says to keep external doors and windows shut while a dehumidifier runs.
• Unblock the air bricks. If you have air bricks to a space under the floor, UKHSA says to make sure they're clear, so air can flow through. If you fitted air brick covers before the flood, take them off.
• Fuel-burning heaters and generators need care. Heaters, dryers and fires must be well ventilated to avoid carbon monoxide poisoning, and UKHSA says never to use petrol or diesel generators indoors.

If your insurer has sent a drying company, it will bring its own dehumidifiers and fans, and should tell you whether to keep windows open or shut.

Cleaning while it dries

• Wear protection. UKHSA advises rubber boots, waterproof gloves and a plastic apron while cleaning up.
• Hard surfaces: clean anything floodwater touched with hot water and detergent.
• No pressure washers. Natural Resources Wales says high-pressure hoses blast contaminated matter into the air.
• Wooden boards and utensils that floodwater reached should be thrown away, UKHSA says.

Mould

Mould can appear while a house is drying. UKHSA says it should disappear as the home continues to dry out, and to contact a specialist cleaner if it doesn't. Damp and mould mainly affect the airways and lungs, and can also affect the eyes and skin, so keep the house ventilated and get advice if anyone in the home has breathing problems.

Checking it's dry

Don't judge it by touch: a wall can feel dry on the surface and still be wet inside.

• Drying certificate. The ABI says repair work should begin shortly after you get your drying certificate from the drying company. The 2010 government guidance describes the certificate being issued once drying goals have been reached.
• If you're not insured, ask whoever does your repairs to check moisture levels in the walls and floors before plastering, laying floors or decorating.

Repairing so the next flood dries faster

When repairs start, ask about resilient materials. Government guidance on resilient repair describes it as repairs where no permanent damage is caused and drying and cleaning are quicker once floodwater has gone. If you're claiming, ask your insurer about Build Back Better, and see our guide to flood-resilient repairs.

Kit that helps

• Dehumidifiers and fans (a drying company brings these on an insured claim)
• Rubber boots, waterproof gloves and an apron
• Hot water, detergent and household disinfectant
• Heavy-duty rubbish bags
• A camera or phone, to photograph damage before anything is removed

FAQs

Can I just turn the heating up as high as it goes?

UKHSA's advice is steady drying with the thermostat at 20°C to 22°C, and only once a qualified engineer has checked the heating.

When can I redecorate?

Only once the walls are dry right through. If you're insured, wait for the drying certificate; repairs follow it.