The key to mould prevention is to remove excessive moisture build-up and control relative humidity through proper home maintenance and by following these steps:

 

Bathroom

• Use an exhaust fan when you shower or bathe. An exhaust fan should be installed in each bathroom.
• Check and maintain exhaust fans to make sure there is adequate air movement and that they are vented to the outside and not into the attic.
• Keep the exhaust fan running for at least 30 minutes after a shower or bath.
• Keep surfaces clean and dry. Squeegee and dry the walls around the bathtub and shower after use.
• Repair or replace open, cracked or damaged tiles, grout and caulking around showers and tubs.
• Repair plumbing leaks promptly.
• Remove any visible mould by scrubbing with unscented dishwashing detergent and water.

 

Kitchen

• Always use a kitchen range hood exhaust fan when cooking, preferably on the highest setting.
• Consider using the back burners only.
• Maintain the exhaust fan to make sure there is adequate air movement and that it vents to the outside.

 

Laundry room

• Washing machine
  • Leave the washing machine door open when not in use so that any remaining water can dry. This will help reduce mould and bacteria growth inside the washing machine.
  • Make sure that the washing machine drains directly into the laundry sink/drain without dripping or splashing outside of the basin. Use pipe extensions to reduce any splashing.
  • Regularly check hoses and connections for leaks.
  • Be aware that hanging wet laundry indoors can increase indoor relative humidity levels.
• Clothes dryer
  • Check that your clothes dryer vents to the outside.
  • Seal the joints in the dryer duct with foil tape.
  • Clean the lint tray every time you use the dryer.
  • Routinely inspect the outside exhaust vent and remove any built-up lint.
  • Make sure the outside vent is kept clear of obstructions, such as snow and foliage.

 

Condensation on windows, window frames and sills

• Promptly repair any leaks.
• Maintain your home's relative humidity level between 30% and 50%.
• Use exhaust bathroom fans and a kitchen range hood.
• Keep window coverings open to allow warm air to reach the windows. Heavy curtains or blinds can trap the cold and moisture and cause condensation on your windows.
• Keep baseboards or heating vents clear of furniture and leave interior doors open to facilitate airflow.
• Dry your window frames and sills daily to keep water from dripping and causing mould to grow.
• Unplug and remove humidifiers.

 

Basement

• Run a dehumidifier in your basement to help reduce dampness year-round, if necessary. Make sure the windows are closed when the dehumidifier is running.
• Check plumbing pipes for condensation. Dry pipes and insulate them with foam insulation.
• Keep areas and storage spaces free of clutter, especially if near an outside wall.
• If you use the basement for storing items, use plastic bins with lids instead of cardboard.
• Never place cardboard boxes directly on the basement floor.
• Consider removing any carpets from the basement floor.

 

General considerations

• Ensure prompt and complete cleanup after a flooding event.
• Store firewood in the garage or shed, not inside the house.
• Have family and friends take off their shoes at the door before entering your home.
• Keep beds, bedding and furniture away from outside walls for good airflow.
• Keep closets and storage spaces free of clutter, especially if near an outside wall.
• Vacuum often. Use a vacuum with a high efficiency particulate air (HEPA) filter, or a central vacuum vented outdoors.
• Clean hard floors with a damp mop.
• Never use bleach to clean up mould.

 

Note: If renting a house or an apartment unit speak to the property owner about any moisture or mould problems. Information on landlord/tenant issues, rights and responsibilities is available from your provincial/territorial government.

For more information, please visit Health Canada's indoor air quality webpage or contact us at air@hc-sc.gc.ca.