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PEHSU Factsheet: Mold in the Home & Schools > How can you reduce dampness and mold in your home or school?

How can you reduce dampness and mold in your home or school?

posted on Aug 26, 2021

The best way to reduce mold exposure in your home is to remove water and moisture sources. Fix leaks, dry damp areas, and lower indoor air humidity (e.g., use a dehumidifier in basements; open a window while taking a shower in bathrooms with no exhaust fan or vent). The best way to clean mold from small area surfaces (less than 3 ft by 3 ft) such as shower walls is to use detergent and water. Additional information about mold and mold removal can be found at the EPA Guide to Mold and The EPA web site Mold Cleanup in Your Home. For larger areas, it is best to contact a professional mold remediation.

These steps will limit mold growth:

  • In schools, personnel must correct leaks and other sources of moisture, and safely remove damp, water-stained, moldy ceiling tiles, and other moldy materials.
  • Fix leaky plumbing and leaks in the building envelope as soon as possible.
  • Watch for condensation/wet spots. Fix source(s) of moisture as soon as possible.
  • Prevent moisture due to condensation by increasing the temperature or reducing humidity.
  • To increase surface temperature, insulate or increase air flow.
  • To reduce the moisture level in air, repair leaks, increase air flow (if outside air is cold and dry), or dehumidify (if outdoor air is warm and humid).
  • Keep heating, ventilation, and air conditioning drip pans clean, flowing, and unblocked.
  • Vent moisture-generating appliances, such as dryers, to the outside.
  • Maintain low indoor humidity, below 65% relative humidity (RH)1, ideally 30-50%.
  • Allow good air circulation between furniture and surfaces like floor, ceiling, and wall
  • Perform regular building/HVAC inspections and maintenance as scheduled.
  • Clean and dry wet or damp spots within 48 hours. 
  • Don’t let foundations stay wet. Provide proper drainage. Slope ground away from the foundation.
  • In schools, maintenance personnel may be able to clean up small areas of mold. Masks, gloves, and other personal protective equipment should be worn. The best way to eliminate mold is to make sure that the source of leaking water is stopped.
  • Mold spores are difficult to kill and some will remain in a home or school even after a cleanup. It is very important to reduce or eliminate moisture in areas prone to mold growth. This can be done by use of exhaust fans in bathrooms and increased ventilation in school rooms. If moisture remains, mold will grow again.