Blog 1


By Apollo Windows President Extract from Feb 24,2023

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:



  • 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.


  • 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.


  • 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



Footnote 1

Health Canada. (2007). Residential Indoor Air Quality Guidelines: Mould. Government of Canada, Ottawa, Canada.

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Footnote 2

Hung LL, Caulfield SM, Miller JD. (2020). Recognition, Evaluation, and Control of Indoor Mold, 2nd edition (AIHA Green Book). American Industrial Hygiene Association, Falls Church VA, USA.

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Footnote 3

Chew GL, Horner WE, Kennedy K, Grimes C, Barnes CS, Phipatanakul W, Larenas-Linnemann D, Miller JD. (2016).; Environmental Allergens Workgroup. Procedures to assist health care providers to determine when home assessments for potential mold exposure are warranted. J Allergy Clin Immunol Pract. 4(3):417-422.e2.

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Footnote 4

Berry P., & Schnitter, R. (Eds.). (2022). Health of Canadians in a Changing Climate: Advancing our Knowledge for Action. ( Ottawa, ON: Government of Canada.

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Footnote 5

Eykelbosh A., Steiner L. (2018). National Collaborating Centre for Environmental Health. Growing at Home: Health and Safety Concerns for Personal Cannabis Cultivation. (

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Footnote 6

Palaty C, Shum M. (2010, rev. 2014). National Collaborating Centre for Environmental Health. Mould Assessment Recommendations. (

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Footnote 7

New York City Department of Health and Mental Hygiene (NYCDHMH). (2008).

Guidelines on Assessment and Remediation of Fungi in Indoor Environments ( 25 p.

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Footnote 8

National Institute for Occupational Safety and Health (NIOSH). (2018). Dampness and Mold Assessment Tool for General Buildings - Form & Instructions. ( Cox-Ganser J, Martin M, Park JH, Game S. Morgantown WV: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2019-115.

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Footnote 9

Health Canada. (2021). Infographic: Flood clean up and indoor air quality. (

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Footnote 10

Institute of Inspection Cleaning and Restoration Certification (IICRC). (2015). ANSI/IICRC S520 Standard and IICRC R520 Reference Guide for Professional Mold Remediation.

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Footnote 11

Mendell MJ, Adams RI. (2022). Does evidence support measuring spore counts to identify dampness or mold in buildings? A literature review. J Expo Sci Environ Epidemiol. 32(2):177-187.

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Condenstation is a recurrent theme on all windows conversation, Condenstation on windows is a big Humidity problem present on your place, not a windows problem. You need to control the humidity levels inside your house for healthy reasons.