Check for Plumbing Leaks
Don't Ignore Mold
Mold can be an early warning sign of a moisture problem inside walls or ceilings that could cause an expensive problem like wood rot. Avoid the temptation to just wipe the mold away and forget about it—find and stop the water source. Learn how to prevent mold before it starts.
Look for Outside Leaks
Inspect the Ductwork
Is it Mold or Dirt?
Use an Antimicrobial Spray
Use Mold-Resistant Building Materials
If you need to build or rebuild an area where moisture has been a problem, use materials that resist mold growth and aren't affected by water. Construct walls with pressure-treated wood and rigid insulation and cover the walls with paperless drywall, which has nothing for mold to feed on. Learn how to install cement board for ceramic tile.
Use Paint With Mildewcide
In areas where mold might grow, such as basement walls, spray the surfaces with an antimicrobial treatment. Paint walls with mildew-resistant primer and paint or add mildewcide to your paint.
Missing Insulation Feeds Mold
Warm air seeks gaps in the insulation, and when it hits colder surfaces as it flows out of or into the house, water condenses—which then feeds mold. These spots often occur on outside walls near floors or windows, at corners and around outlets and lights. If the mold disappears after cleaning it and lowering indoor humidity with a dehumidifier or vent fan, just keep an eye on it. If it recurs, open the wall and fix the problem. Learn how to properly use expanding foam.
Win the War Against Bathtub Mold
To prevent mold around the tub or shower, spray the wall with an antimicrobial treatment, then seal the grout with two coats of grout sealant to keep water from wicking in. If the mold is extensive and tiles come off, rebuild the wall with cement board tile backer and new tile. If the wall is sound but the mold stains won't go away, try regrouting. Scrape out the caulk and stained grout, spray the wall with antimicrobial treatment, regrout and caulk, and then coat the whole wall with grout sealant.