What Should You Do If You Find Mold in Your Home?

Mold is a common problem in damp homes, and it can grow on many surfaces within 24 to 48 hours of water exposure. Mold spores are always in the air, but they only become a problem when they land on a wet surface and start to grow. The good news is that most small mold problems can be handled by fixing the moisture and cleaning up safely. The key is to act quickly and to protect your health while you work.

What is happening

Mold growth is a sign of excess moisture. Common causes include leaking pipes or roofs, condensation on windows and cold walls, high indoor humidity, flooding and poor ventilation in bathrooms, kitchens and laundry areas. Mold can cause musty odors and may trigger allergy-like symptoms such as sneezing, coughing, itchy eyes or skin irritation, especially in people with asthma or weakened immune systems.

Emergency warning

If you see mold covering a large area, if the building has been flooded with sewage or contaminated water, or if you or anyone in the home has trouble breathing, chest pain or severe allergic reactions, leave the area and call local emergency services or a medical professional right away. Do not try to clean up a major contamination yourself.

10 steps to deal with mold and moisture

1. Find the moisture source. Look for leaks, drips, condensation, high humidity or recent water damage. Mold will return if you do not fix the cause.
2. Protect yourself. Wear an N95 respirator, gloves and eye protection. Keep children, older adults and anyone with breathing problems away from the area.
3. Ventilate the space. Open windows and use fans to move air, but do not blow mold spores into clean areas.
4. Seal off the work area if the mold is in one room. Use plastic sheeting and tape to keep dust and spores from spreading.
5. Remove porous materials that are moldy and cannot be cleaned, such as drywall, insulation, carpet and ceiling tiles. Bag them and dispose of them properly.
6. Clean hard surfaces. Use soap and water or a suitable household cleaner. For non-porous surfaces, a diluted bleach solution may be used, but never mix bleach with ammonia or other cleaners. Follow label directions and ventilate well.
7. Dry everything completely within 24 to 48 hours. Use fans, dehumidifiers and open windows. Damp materials will grow mold again.
8. Repair the cause. Fix leaks, improve drainage, insulate cold surfaces and repair roof or plumbing problems.
9. Control indoor humidity. Keep humidity below 50 percent if possible. Use exhaust fans in bathrooms and kitchens, and run a dehumidifier in damp areas.
10. Check for hidden mold. Look behind walls, under floors and in crawl spaces if you smell mold but cannot see it. A professional can help find hidden problems.

What NOT to do

• Do not ignore the moisture source. Cleaning mold without fixing the water problem is temporary.
• Do not mix bleach with ammonia or other cleaning products. This can create dangerous fumes.
• Do not dry-brush or sand moldy surfaces, which can send spores into the air.
• Do not use a regular vacuum or a fan to clean up mold.
• Do not try to clean large areas of mold yourself. Call a professional.

When to seek professional help

Call a mold remediation professional if the mold covers more than about 10 square feet, if it is in heating or ventilation systems, if the water damage came from sewage or flooding, or if you have health concerns. If you feel unwell after exposure, contact a medical professional.

How to prevent it

Keep your home dry. Fix leaks quickly, use exhaust fans, run a dehumidifier in damp spaces, and clean up spills within 24 to 48 hours. Regular inspection of roofs, pipes and windows can catch problems early.

Start by finding the moisture source today. If the mold is small and on a hard surface, clean it safely and dry the area completely. If it is large or keeps coming back, get professional help.