Heavy rains and floodwater will cause mold to grow inside homes and buildings if water gets inside. Mold can start to grow after an area has been wet for 24 hours. The best way to prevent mold growth and stop growth that has already started is to dry the wet areas as quickly as possible. If a building flooded, additional concerns during cleanup are bacteria from sewage overflow, industrial and agricultural waste, and chemicals released from various sources in the community.
Steps to Clean Up
Make sure it’s safe to enter
A home that was flooded should not be entered unless the electricity is turned off and the building is structurally sound. EPA has guidelines for making sure a flooded home is safe to enter. If your home had leaks during a storm, make sure the electricity is cut off in parts of the house where water got in until cleanup is complete.
Fix water intrusion
Leaks should be fixed as soon as possible. Check your home for storm damage like holes in roofs or siding, missing shingles, or broken windows. Roof or window leaks that can’t be fixed immediately should be covered with tarps to keep more water from getting in. Any damage to plumbing should be fixed immediately.
Dry the home to prevent mold growth
Dry out your home as soon as you are able. Mold starts to grow within 24 hours, so it’s best to dry the home out within one to two days if possible. This can be done by opening doors and windows to air out your house. If electricity is available, fans can be used to shorten the drying time. A home that has been flooded should not be entered until the electricity is cut off, but portable generators can be set up outside away from windows and doors. Generators can be a carbon monoxide poisoning hazard if not used safely.
Throw out wet items that are porous and won’t dry quickly. These include carpeting, mattresses, rugs, upholstered furniture, and pillows. Other items that should be discarded include drywall and insulation that has been in contact with floodwater.
Cleaning items
Before sanitizing, clean off dirt and debris. This can be done with regular household cleaners and detergents. Afterwards, hard surfaces can be sanitized with diluted household bleach (5% to 9% sodium hypochlorite). If there is no mold growing on the surface, use a mixture of 1 tablespoon of household bleach in one gallon of water. If there is mold growing on the surface, use a mixture of 1 cup of household bleach in 1 gallon of water. Food contact surfaces like plates and countertops should be sanitized and rinsed with clean water.
Metal items like silverware and pots and pans can be discolored if cleaned with bleach. Instead, these can be cleaned with household cleaners or detergents, rinsed with clean water, and boiled for 10 minutes.
Clothing, sheets, and towels that have not been seriously damaged may be able to be laundered. Wash with hot water, laundry detergent, and bleach if possible. Delicate items may be able to be dry cleaned. If cloth items are very dirty or moldy, they may need to be thrown out. Some stuffed toys may be able to be laundered, but in most cases are best thrown out. Stuffed toys that were in flood water should be thrown out. If cloth items cannot be washed immediately, they should be hung outside to dry out.
Cleaning safely
While cleaning up moldy areas, wear an N-95 mask, gloves, and eye protection. If a home was flooded, also wear hard sole shoes and long pants during cleanup. Do not let open cuts or wounds come into contact with flood water.
Never used bleach in an enclosed space. Open doors and windows first. Never mix bleach with ammonia. This can generate poisonous gases. Do not mix household cleaners together. Follow the directions on the label.
Follow-up
Wash all clothes worn during cleanup separately from other laundry with hot water and detergent. Seek medical attention if you become injured or sick.