After a hurricane blows through and the heavy rains recede, or the snow starts to melt after a blizzard, your problems may be just beginning. Water damage from a flood can quickly lead to mold, posing serious health risks. 

Controlling moisture is the key to preventing mold. According to OSHA, mold spores continually float through indoor and outdoor air, enabling mold to grow on virtually any substance when moisture, oxygen and an organic source are present. Mold can significantly impact indoor air quality, so acting quickly after sustaining water damage is important.

By finding and eliminating sources of moisture, you can reduce the chances of ever getting mold in the first place. These tips can help you start the clean-up effort and help prevent mold.

How long does it take for mold to grow after a flood?

The microorganisms that turn into mold colonies are always in the air around us so mold growth will start quickly—within 24 to 48 hours of water exposure. Mold colonies will continue to grow as long as the moisture level is high. According to the CDC, mold often grows on wood, paper products, ceiling tiles and cardboard. Mold can also grow in dust, insulation, drywall, wallpaper, paints, carpet, fabric and upholstery.

What’s the best way to prevent mold after flooding?

The only way to prevent mold from growing is to dry the affected area as quickly as possible. To do this, take these steps:

1. Open up the building if it’s less humid outside. (Generally, you’ll want to open the building during the day and close it up overnight.)
2. Remove all debris and wet items. Get rid of any soaked porous or absorbent material that you can (like ceiling tiles, papers, and wet insulation)
3. Clean exposed surfaces with disinfectants or sanitizers. Scrub hard surfaces like tile, stone and wood with soapy water and a bristle brush. Thoroughly dry surfaces after cleaning and disinfecting.
4. If you can’t get rid of saturated carpeting right away, remove water from it with a carpet extractor or wet/dry vacuum.
5. Use fans to circulate air into the space and speed evaporation unless mold has started to grow. Fans can spread existing mold. 
6. Use dehumidifiers to reduce the moisture content of the air and help things dry more quickly, especially in closed areas. A home and office dehumidifier may be enough for smaller areas, but large spaces and moisture-saturated areas may require an industrial/commercial dehumidifier or even a specially designed restoration dehumidifier.

Low relative humidity pulls moisture out of these surfaces, and humidity levels below 50 percent will discourage mold growth. You can use a moisture meter to get accurate readings.