Act Quickly to Beat Mold After a Flood

Medically Reviewed by Louise Chang, MD on October 30, 2012
From the WebMD Archives

Oct. 30, 2012 -- If you’re trying to clean up a house flooded by Hurricane Sandy, be aware that you’re in a race against mold and bacteria, which can grow quickly in damp environments.

Mold is especially dangerous for people with breathing problems caused by allergies or asthma. But high levels of mold can also cause problems for people who are relatively healthy. Symptoms of mold exposure include wheezing, shortness of breath, sore throats, flu-like aches and pains, and fatigue.

Mold isn’t the only threat from flooding. Bacteria may also be a problem if your house was soaked by sewage. Bacteria can cause dangerous gastrointestinal and skin infections.

That’s why it’s important to stop these pathogens before they take hold of your home.

“You’ve really got 24 to 36 hours to work with,” says Rebecca Morley, executive director of the National Center for Healthy Housing, a nonprofit organization that wrote a guide to help residents clean up flooded homes after Hurricane Katrina.

The good news is that the faster you act, the more you may be able to save.

DIY Cleanup? Or Call a Pro?

The first thing to do is to pump out or soak up any standing water. But be careful: If you’ve got several feet of water in a basement, where fuse boxes and other electrical circuitry may be submerged, have emergency workers clear the space before you get to work.

If you have a lot of water in the house, Morley, who has been through two floods herself, says hiring help can be a good investment.

“I had water up to my ankles. My carpet was floating when I got home,” Morley says. “These restoration companies have all the heavy equipment that’s needed to dry out a place quickly. They bring in their big fans, their big dehumidifiers.”

You might also need a professional if your house was flooded with sewage, which has an unmistakable smell. Sewage is hazardous and best handled by someone who’s trained.

Getting Started

  • Start hauling wet things, especially plush items like pillows, upholstered furniture, or curtains out of the house to a place like the garage or the driveway where they can dry. “They are going to be the more challenging things to salvage,” Morley says.
  • Use a shop vac or wet vac to suck water out of soggy carpets.
  • Fans can help get air moving in enclosed spaces, but they may not be enough.
  • Consider renting or buying a dehumidifier to keep moisture levels low in the air in rooms you’re trying to dry. Basements and big areas may require larger, commercial-sized machines. “You want to get as much air movement as possible over the wet areas,” says Arthur Lau, a certified microbial investigator for Microecologies, a national restoration and cleanup company.
  • Remove baseboards and moldings from flooded walls, especially if the walls are made of sheetrock. “Baseboards really prevent the lower few inches of wet walls from drying out, no matter how much air you put on it,” Lau says.
  • Cut small openings along the bases of walls to let air into the wall to dry the back as well as the front of the sheetrock. “The paper covering on sheetrock is on the front and back sides. So you may see nothing on the room-side surface, but you don’t know what’s happening on the backside,” Lau says.


After Mold Starts Growing

If the power has been off for a few days, mold may have already gotten the upper hand by the time you’re really able to start cleaning. Both the CDC and the EPA recommend bringing in a trained professional to clean up mold that covers more than 100 square feet or a 10-foot-by-10-foot area. Some states require contractors that clean up mold to be licensed. At the minimum, anyone you hire should have experience getting rid of mold, references you can call, and liability insurance.

If you’re cleaning a smaller area, you can wash mold off most hard surfaces with a mixture of detergent and hot water. The EPA doesn’t recommend using chlorine bleach or other biocides -- chemicals that kill living organisms -- to clean up mold unless there are special circumstances, such as a person living in the home who has a weakened immune function.

If you prefer to use bleach to clean up mold, the CDC recommends mixing a solution of no more than one cup of bleach for every gallon of water. And be careful not to mix it with ammonia or cleaners that contain ammonia.

Save or Toss?

The National Center for Healthy Housing recommends tossing the following items if they look or smell moldy or they’ve been underwater:

  • Carpet, carpet padding, and rugs
  • Upholstered furniture
  • Computers, microwaves, window A/C units, or any appliances that have fans that were sitting in moldy rooms
  • Papers and books
  • Food items, including canned foods if they were in contact with flood waters

Items that can usually be cleaned and saved include:

  • Hard, non-porous items like jewelry, china and dishes, glass, porcelain, and metal
  • Wood furniture, even if it’s moldy, as long as it’s in good condition
  • Some electronics and small appliances, depending on flooding conditions
  • Photographs, books, and valuable legal documents with only small levels of mold
  • Artwork, textiles, or clothing that has no physical damage

Keep in mind that undamaged items may need to be stored away from the house while you dry it out.

Clean hard surfaces that have small amounts of mold with detergent and “as little water as possible,” Morley says. “The most important thing is to keep things dry,” she says.

Protective Clothing

Also, if you can see mold growing, you should take precautions to keep from breathing it in. Wear an N95 respirator mask, which can be purchased at hardware stores. You may also want to consider heavy work boots and puncture-resistant gloves to protect your hands and feet from sharp objects if you’re also dealing with debris.

Show Sources


The National Center for Healthy Housing: “Creating a Health Home: A Field Guide for Clean-Up of Flooded Homes.”

EPA: “A Brief Guide to Mold, Moisture, and Your Home.”

Arthur Lau, certified microbial investigator, Microecologies, New York, N.Y.

Rebecca Morley, executive director, National Center for Healthy Housing, Columbia, Md.

© 2012 WebMD, LLC. All rights reserved. View privacy policy and trust info