Cleaning up indoor mould is important for health and safety. The information here is about:
- How to protect yourself and others during cleanup.
- When to call a professional.
- How to safely clean up mould and prevent it from coming back.
If you rent your home or building, talk to your landlord about concerns with mould or moisture. For unresolved health concerns with rental homes, contact
Environmental Public Health.
Safety
Safety is the most important thing when you're dealing with mould. Keep anyone with breathing problems or a weak immune system away from the work area. Then take these precautions for mould cleanup:
- Wear personal protective equipment, including an N95 mask, eye protection, and rubber gloves.
- Open windows and doors to bring in fresh air.
- Put mouldy waste into a plastic bag and seal it. Throw it away in a regular outdoor garbage bin.
If there is more than a small amount of mould:
- Isolate the work area using floor-to-ceiling plastic sheets with a slit entry and covering flap.
- Seal openings or pathways that let air move into the work area, such as air vents, holes around pipes, and electrical outlets.
When you are finished, leave the work area clean, dry, and mould free.
When to hire a professional
When deciding if you need to hire a professional (mould-remediation contractor):
- Check the source of moisture.
- Look at the amount of mould.
- Note what the building is used for and any safety concerns for the people who use it.
Air testing for mould is usually not recommended, especially if you can see mould.
Moisture source
If moisture is from a flood or sewer backup, harmful bacteria may be present. Refer to Flooding Resources and Safety Information for cleaning homes and businesses after a flood.
Moisture problems must be fixed to prevent mould from coming back. You may need to hire a contractor or plumber.
Amount of mould
- Small areas (1 to 3 patches of mould, each less than 1 square metre/10 square feet): You can usually clean up small areas yourself.
- Medium areas (more than 3 patches of mould of patches that are 1 to 3 square metres/10 to 32 square feet): You may be able to clean up medium areas yourself. Use the proper personal protective equipment and cleaning procedures. Consider hiring a professional.
- Hire a professional for rental homes, public facilities (like schools, daycares, and hospitals), and businesses with medium amounts of mould.
- Large areas (more than 3 square metres/32 square feet of dense mould): Hire a professional to clean up large areas.
Building use and occupants
- Consider hiring a professional if the building is mostly used by people with health risks. This includes babies, older adults, and people with breathing problems, mould allergies, or a weak immune system.
- You need to hire a professional to clean up mould in homes used as illegal marijuana grow operations.
Other safety concerns
- You may need to hire a professional for foundation, roof, or exterior wall problems. You may need a plumber for leaky plumbing fixtures or sewer backups.
- Some buildings built before the mid-1990s have asbestos, which is harmful to breathe in.
Steps to clean up mould
Follow these steps if you are cleaning up the mould yourself:
1. Wear personal protective equipment
- Always wear proper personal protective equipment for safety.
- Use a tight-fitting N95 mask, gloves, and eye protection to limit contact with the mould.
2. Clean and remove
- Non-porous materials—like finished wood, glass, metal, plastic—can be cleaned with soap (like dish soap) and water.
- Semi-porous materials—like unfinished wood, concrete—can sometimes be cleaned with soap and water. Remove them if they are badly damaged and won't come clean.
- Porous materials—like drywall, carpet, ceiling tiles, fabric-covered furniture—usually need to be removed and thrown out. If there is a small amount of mould on drywall that wipes clean with soap and water, the drywall doesn't need to be removed.
- Clean surfaces in and around the work area with soap and water to remove mould spores and fragments.
If there is mould in a heating, ventilation, and air-conditioning (HVAC) system, call an HVAC company for help.
Step 3. Dry and prevent
- Dry the work area completely to prevent mould from coming back.
- Improve airflow and lower humidity to prevent mould in the future.
Using biocides (chemicals)
Biocides are products like chlorine bleach that kill living organisms. They should not be used to clean up mould from sufaces.
You may choose to use a biocide after mouldy surfaces have been cleaned very well with soap and water. When you use a biocide, open windows and doors for airflow.
Never mix different types of cleaning chemicals, like bleach and vinegar or ammonia-based products. Mixing them can be dangerous.
