How to Clean and Disinfect After Floodwater

A step-by-step guide to flood cleanup from CDC, EPA and university extension advice: the gear to wear, what to throw out, how to clean before you disinfect, the safe bleach mix, and when to stop and call a pro.

By Patrick & Dylan · Florida Certified General Contractor, Lic. #CGC1541672

Floodwater isn't just water. The CDC warns it may contain sewage, and Texas A&M AgriLife tells homeowners to "assume flood water and flooded materials are contaminated." This guide pulls together what the CDC, the EPA, the Red Cross and university extension services say about cleaning up safely: what to wear, what to throw out, how to clean and then disinfect, and when the job is no longer a do-it-yourself job.

Be honest with yourself before you start. The EPA calls flood cleanup "difficult and dangerous work" and says it may be best to get help from experienced professionals if you can. If you do it yourself, follow every step below.

Stop and call a pro before you start if:

The house may be structurally damaged. The CDC says not to go back in until a building inspector has examined it.
You smell gas. The CDC says to turn off the main gas valve if you can, open the windows, leave right away, and avoid anything that could make a spark.
Water reached outlets, the panel or appliances. The CDC says never to turn power on or off yourself, or use electric tools, while standing in water; if you'd have to step into water to reach the main switch, call an electrician to shut it off. NC State Extension says to have a flooded electrical system checked by an electrician, and the Red Cross says flooded appliances should be checked by a professional before you use them.
The water was sewage. The EPA says to call in a professional experienced with contaminated water.
Mold covers more than about 10 square feet. The EPA says you can usually handle mold under about 10 square feet yourself; for more than that, it points to its professional remediation guidance. Our advice: call a professional for mold over about 10 square feet. Florida's mold-licensing law exempts homeowners working on their own home (s. 468.841).
The home was built before 1978, or you suspect asbestos. The EPA warns older homes may contain asbestos or lead, and its lead-safe guidance for DIYers applies to homes built before 1978. Texas A&M AgriLife says asbestos tiles should be removed only by a trained professional, and not to sand or scrape lead-based paint.
The flood reached your A/C ducts or air handler. The EPA says not to use a flood-affected HVAC system to dry out the house, not to run it if you suspect it's contaminated with mold, and that cleaning it is best left to a professional.
You have asthma or a weakened immune system, or you're pregnant. The EPA says people with breathing problems or weakened immune systems should not take part in flood cleanup, and neither should children or pregnant people.

What you'll need

Person in a white protective suit, safety glasses, respirator mask and gloves — Respirator, goggles, gloves and covered skin, on before you start and kept on the whole time.

Protective gear (from the EPA and CDC)

Item	Why	Where to buy
N95 respirator (or better)	The EPA and CDC both list one for flood cleanup	Home Depot · Lowe's
Goggles without vent holes	Keeps splashes and spores out of your eyes	Home Depot · Lowe's
Rubber gloves, plus heavy work gloves	Rubber for contaminated water; the CDC also lists heavy work gloves	Home Depot · Lowe's
Waterproof boots	The CDC lists waterproof boots with a steel toe and insole	Home Depot · Lowe's
Long pants and a long-sleeved shirt	The EPA says to cover your arms and legs	Clothes you can wash in hot water

Hands in yellow rubber gloves holding a blue sponge and a spray bottle — Detergent and water first, disinfectant second.

Cleaning supplies (from the Red Cross, NC State Extension and EPA)

Item	Why	Where to buy
Wet/dry shop vacuum	Pulling up leftover water and debris	Home Depot · Lowe's
Shovel, mops and brooms	Mud, silt and standing water	Home Depot · Lowe's
Buckets, sponges and scrub brushes	Washing walls, floors and furniture	Home Depot · Lowe's
Low-sudsing detergent	Cleaning every surface before you disinfect	Home Depot · Lowe's
Household bleach or a disinfectant	Disinfecting hard surfaces after cleaning	Home Depot · Lowe's
Heavy-duty trash bags	Everything you throw out	Home Depot · Lowe's
Fans, a dehumidifier and a moisture meter	Drying and checking that it's dry	Home Depot · Lowe's

Leave ammonia off your list. The CDC says never to mix bleach with ammonia or any other cleaner, and the EPA warns that bleach can react with chemicals carried in by the floodwater too.

Step by step

Step 1: Air the house out before you work

The CDC says to go in briefly and open doors and windows so the house airs out for at least 30 minutes. The Red Cross says that if the house was closed up for more than 48 hours, air it out before staying inside for any length of time. Never run a generator, pressure washer or anything gas-powered inside the house or garage; the EPA says to keep generators outside and at least 20 feet from the building, and the CDC adds away from windows, doors and vents, because carbon monoxide can kill in minutes.

Step 2: Photograph everything

Our advice: take wide video of each room and close-ups of the water line, damaged belongings and anything you're about to throw out, before it leaves the house. Don't throw anything out until it's in a photo.

While you work, the CDC says to cover any clean, open wounds with a waterproof bandage, and to ask a health care professional whether you need a tetanus booster.

Step 3: Get the water and mud out

Dark room with standing water across the floor and peeling, water-stained walls — Get standing water and mud out first, before it dries in place.

NC State Extension says to shovel out mud and silt before it dries. Then pull up remaining water with the shop vac. If a space below grade is full of water, the Red Cross and NC State say to pump it out gradually, about a third of the water a day, to avoid structural damage.

Step 4: Sort what stays and what goes

Person in orange coveralls carrying two blue trash bags next to a pump sprayer — If it soaked up floodwater and can't be cleaned and dried, it goes.

The EPA's rule of thumb: you can usually clean and dry things that don't soak up water, and you should throw away things that soak up a lot of water and can't be cleaned and dried.

Throw away (CDC): mattresses, carpeting and carpet padding, rugs, upholstered furniture, pillows, foam-rubber items, stuffed animals, baby toys, cosmetics, books, wall coverings and paper products. Texas A&M AgriLife says flooded carpet pads should always be thrown out.
Throw away (CDC and Red Cross): drywall and insulation the floodwater reached, any food that touched floodwater, and wooden cutting boards, wood or plastic utensils, and baby bottle nipples and pacifiers that touched it. Our guide to cutting out wet drywall covers the wall removal.
Clean (CDC): any flooring, concrete, molding, wood and metal furniture, countertops, appliances, sinks and other plumbing fixtures. Have flooded appliances checked by a professional before you use them, as the Red Cross advises.

Canned food is a judgment call where the sources differ: the Red Cross says to throw out canned goods that touched floodwater, while the CDC says undamaged, commercially made all-metal cans can be saved if you remove the labels, wash, rinse and disinfect them, and re-label them. When in doubt, throw it out.

Step 5: Clean every surface with detergent first

Flat mop being pushed across a wood floor — Wash with detergent and water before any disinfectant goes on.

This is the step people skip. The EPA says that before you use bleach or any other disinfectant, you need to thoroughly clean the surface with clean water and detergent, because those products don't work on surfaces that haven't been cleaned.

NC State Extension says to wash down flooded walls and floors before they dry, starting at the top of the flood line and working down.
The EPA says to clean gently the first time with a cloth dampened with clean water and detergent, then use a wet/dry vac to pick up what's left.
The Red Cross says to clean hard surfaces with hot water and soap or detergent.

Step 6: Disinfect hard surfaces

Once a surface is clean, disinfect it.

Commercial disinfectants: the Red Cross says you can disinfect with bleach or a commercial disinfectant; follow the directions on the label.
Bleach for mold: the CDC's mix for cleaning mold is 1 cup of household bleach in 1 gallon of water, and its mold guidance says to use no more than that.
Ventilate: the CDC says never use bleach in a closed space; open windows and doors first.
Never mix: bleach with ammonia or any other cleaner.
Contact time: the EPA says disinfectants have to stay on the surface for the time on the product label.
Know the limits: the EPA says many disinfectants aren't meant for surfaces that soak up water, like fabric or unfinished wood. Texas A&M AgriLife adds that bleach will not prevent new mold growth on materials that stay damp, which is why drying matters as much as disinfecting.

For dishes, the Red Cross says to throw out the wood and plastic items listed above, wash metal pans and ceramic dishes in hot, soapy water, and then sanitize them by boiling or by soaking them for 10 to 15 minutes in 1 tablespoon of unscented bleach per gallon of water.

Wash clothes that touched floodwater in hot water and detergent before wearing them again, as the CDC advises.

Step 7: Dry everything completely

Empty, unfinished space with block walls and open ceiling joists — Open, empty and ventilated: the house dries faster with nothing left to hold water.

The CDC says to clean up and dry the home within 24 to 48 hours if possible, and the EPA says mold can grow on wood, drywall, carpet and furniture that stay wet for more than 24 hours.

Fans and dehumidifiers: the EPA says to use them if you have power. If you can already see mold, the EPA says to gently clean it first, then start the fans.
Open up hidden spots: the EPA says to remove drawers, shelves and built-ins like cabinets so the surfaces behind them can dry.
Don't use a flooded A/C system to dry the house, per the EPA.
Furniture: Texas A&M AgriLife says to take furniture outdoors to clean it and dry it slowly out of direct sun, which can warp it. It may take several weeks to several months to dry.

Step 8: Check that it's dry before you rebuild

The EPA says materials should read 15% or less on a moisture meter before refinishing, and not to seal or paint anything that got wet until you're sure it's dry inside. For a concrete slab, the EPA suggests taping a clear plastic sheet to the floor; if moisture shows on it after about 16 hours, the slab is still too wet for new flooring.

How long it takes

Plan for the drying, not the scrubbing. The EPA says drying usually takes several days to weeks. Mississippi State Extension says to allow at least 4 to 6 weeks for walls to dry completely, and the Red Cross says the structure can take weeks or months.

Stop and call a pro if, once you've started, you find:

Mold spreading, or more than about 10 square feet of it.
Sewage, or a smell that suggests it.
Sagging ceilings, soft floors or other signs of structural damage.
Water inside electrical boxes, the panel, or the A/C system.
Moisture readings that won't come down to 15% or less after weeks of drying (our advice).

When everything is clean and dry, the rebuild is where we come in: new drywall, trim, doors and cabinets, with any permits, and trade work through licensed partners. See our hurricane and storm damage repair page or read what to do in the first 48 hours after water gets inside.

Frequently asked questions

What's the right bleach mix for cleaning mold after a flood?

The CDC says 1 cup of household bleach in 1 gallon of water, and no stronger. For other disinfectants, follow the label. Clean the surface with detergent first, open windows and doors, and never mix bleach with ammonia or any other cleaner.

Do I need to clean before I disinfect?

Yes. The EPA says disinfectants and sanitizers don't work on surfaces that haven't been cleaned, so wash with clean water and detergent first.

Can I save furniture that sat in floodwater?

Usually not upholstered furniture, mattresses or pillows; the CDC lists them as things to throw away. The CDC says to clean wood and metal furniture, and Texas A&M AgriLife says to clean furniture outdoors and dry it slowly out of direct sun.

Who shouldn't help with flood cleanup?

The EPA says children, pregnant people, and people with asthma or other breathing problems or weakened immune systems should not take part in flood cleanup.

Sources

General information, not legal, insurance or engineering advice. Rules change and vary by city; confirm with your building department, DBPR, your insurer, an attorney or an engineer as fits.

How to clean and disinfect after floodwater gets in your home