Moisture in The Home

This fact sheet provides answers to basic questions about moisture in homes. It discusses sources of moisture, how they can affect your home, and what you can do to prevent moisture problems.

What are some common ways my home is exposed to moisture?

  • Plumbing, flashing, and roof leaks
  • Damp basements and crawlspaces
  • Cooking, showering, and indoor line drying of clothes
  • Humidifiers
  • Improperly vented combustion appliances and clothes dryers
  • Flooding and sewer backups
  • Poorly maintained gutters, downspouts and drains
  • Landscaping and plants that block crawlspace vents and drainage systems

How can moisture affect my home?

Excess moisture in your home can cause mold to grow. Mold can grow in or on almost anything in your home, including paper, carpet, wood, dry wall, insulation, mattresses, and shower curtains. Mold also can grow in improperly maintained air conditioners, humidifiers and dehumidifiers. Excess moisture provides a good environment for bacteria, cockroaches and dust mites.

Moisture in your home can cause other problems. Too much moisture can cause wood to rot, which may weaken the structure of your home. Moisture can cause peeling, chipping or cracking paint, which, if your home was built before 1978, may contribute to high levels of lead in household dust.

How can moisture in my home affect my health?

Mold, bacteria, cockroaches, and dust mites have been linked to triggering allergies and asthma attacks and may even cause children who do not have allergies or asthma to develop either condition. Exposure to mold, bacteria, cockroaches, and dust mites also can cause coughing, sneezing, wheezing, upper respiratory irritation and asthma symptoms.

Having high levels of lead in household dust can cause lead poisoning, the leading environmental illness in children. Exposure to lead in household dust can cause behavioral disorders, learning problems and slower growth in children.

I have mold in my home, but the landlord will not clean it up or fix the moisture problems. What can I do?

While local housing ordinances may not specifically address moisture or mold problems, the ordinances do state that the landlord is responsible for keeping the home fit to live in and making necessary structural repairs to comply with housing codes. Some mold problems may be the result of building or property maintenance code violations. If you feel that the property owner is not responding to your concerns about mold, you should contact the department responsible for building or property maintenance code enforcement in your community. The Illinois Department of Public Health does not have enforcement authority over mold and moisture issues, but we can provide information and advice to property owners and tenants.

How can I prevent mold and other moisture problems in my home?

Preventing moisture problems is the most important way to control mold indoors. Here are several simple ways to prevent moisture from becoming a problem in your home:

  • Fix plumbing, flashing and roof leaks as soon as possible.

  • Cover dirt in crawlspaces with plastic sheeting, and appropriately ventilate the crawlspace.

  • Install exhaust fans in the kitchen and bathroom. Always use exhaust fans when cooking and showering.

  • Avoid using humidifiers since they will add moisture to your home and may cause mold growth. However, if you must use a humidifier, change the water daily and clean the tank weekly.

  • Use air conditioners or dehumidifiers to control moisture in humid weather. Air conditioners and dehumidifiers should be regularly cleaned and maintained.
  • Improve air circulation in your home by opening windows when weather permits, using fans, and keeping doors between rooms open.

  • Prevent water from entering basements and crawlspaces by repairing holes and cracks in walls; use landscaping to direct water away from your foundation.

  • Clean and maintain your gutters, and make sure drain pipes carry water several feet from your home.

  • Keep the relative humidity in your home between 40 percent and 60 percent. You can purchase a device to accurately measure relative humidity levels.

  • Always vent clothes dryers outside of your home.

Where can I get more information?

Illinois Department of Public Health
Division of Environmental Health
525 W. Jefferson St.
Springfield , IL 62761
TTY (hearing impaired use only) 800-547-0466

Rev. Sept. 2011

idph online home
Environmental Health Home

Illinois Department of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Phone 217-782-4977
Fax 217-782-3987
TTY 800-547-0466
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