Why mold follows water
Mold spores are everywhere indoors and out. What they need to grow is moisture, and a wet wall, carpet pad or subfloor provides it. The EPA's advice is to dry water-damaged areas and items within 24 to 48 hours to prevent growth, and to fix the source of moisture first, since cleaning mold without fixing the water problem doesn't last.
Signs of mold after a leak
- A musty, earthy smell, especially in closed rooms, closets or under sinks
- Spotting or discoloration on drywall, baseboards or the backs of cabinets
- Warped or bubbling paint and wallpaper
- Allergy-like symptoms that ease when you leave the house
Small areas vs professional remediation
The EPA suggests that a homeowner can usually clean small areas of mold on hard surfaces, less than about 10 square feet, with detergent and water while wearing gloves and an N95 mask. Larger areas, mold inside walls or HVAC ducts, mold after sewage or floodwater, and homes with people who have asthma or weakened immune systems call for professional help.
Preventing mold after water damage
- Start professional drying within 24 to 48 hours
- Remove carpet pad, insulation and drywall that can't be dried quickly
- Keep indoor humidity below about 60 percent, ideally 30 to 50 percent
- Confirm dryness with moisture readings before closing walls or laying new flooring