How to get rid of mould in the home

HomeMaintaining a homeHouse
Updated on July 8, 2026
3 mins reading time
A woman, looking troubled, looks at the mould stains on the walls of her basement.

Mould can take hold in just 48 hours on any wet or damp material. Wood, gypsum board and some textiles are the most vulnerable materials in your home. Since mould can affect your indoor air quality and your health, act fast. Fix the moisture source, then clean.

What is mould?

Health Canada defines mould as very small fungi that grow on damp materials or food. Mould is a natural part of the environment, but once it builds up indoors it can trigger health problems and degrade your indoor air quality.

How to spot mould in the home

Watch for these common signs:

  • Green, black or brownish stains
  • Fuzzy or powdery deposits
  • White filaments behind materials like wallpaper
  • A strong musty or earthy smell

A ceiling corner contaminated with mould that a person is trying to clean using a spray bottle and a cloth.
How to find the cause before cleaning

Mould always comes back to one thing: excess moisture. The usual culprits are:

  • A plumbing failure in the bathroom or elsewhere
  • Excessive humidity
  • Condensation in the walls

Fix the source of the excess moisture first—a small water leak, for example—before you worry about cleaning. If you skip this step, the mould will be back before you know it.

Can you clean up mould yourself?

You can do it yourself if you’re in good health and if:

  • The contaminated area is roughly 100 sq. ft. or less
  • The mould was caused by clean water

First, gear up with:

  • A suitable dust mask (type N95 or equivalent)
  • Safety glasses
  • Rubber gloves or disposable household gloves
Expert’s insight

“Keep everyone away from the work area throughout the entire job. If necessary, seal off the area with polyethylene vapour barrier sheeting to keep other rooms clean. Keep the area under negative pressure to prevent mould from spreading throughout the home.”

Yves AllardAssistant Director, Residential, CAA-Quebec

How to clean mould effectively

First, vacuum up the surface particles with a HEPA vacuum. Do not dry-brush, as this scatters spores into the air and only makes the problem worse.

If building materials like gypsum board or wood are badly contaminated, you will probably need to remove and replace them.

Products to favour and to avoid

Reach for mild cleaners suited to the surface and skip the bleach.

  • It can give off irritating fumes.
  • On porous materials, it doesn’t always reach the mould underneath.

Cleaning mould on different surfaces

Surface

Cleaning solution

Technique

Smooth surfaces (including silicone joints)

Water + mild detergent (unscented dish soap)

Wipe with a damp cloth, rinse, and dry well so no moisture lingers.

Gypsum board (small areas)

Water + mild detergent or baking soda

Wipe gently with a barely damp cloth. Be careful not to soak the material. Check to see if the back is affected, too.

Wood (e.g., window frames)

Water + mild unscented detergent

Scrub with a damp cloth or sponge, and dry quickly.  Sand lightly if needed and vacuum as you go.

Concrete

Water + unscented soap

Heavy contamination: Trisodium phosphate diluted with water (biodegradable TSP)

Wet, brush, rinse and repeat as needed.

Once you’re done, ventilate the room well until everything is completely dry.

What if the mould comes back?

If the mould returns or the contamination is significant, it’s time to call a company that specializes in decontamination or post-disaster response.

These professionals can treat the root cause and prevent the spores from spreading.

Is mould covered by home insurance?

Insurers usually won’t cover damage caused by the gradual deterioration that mould causes.

That said, you may be compensated if the mould resulted from sudden and accidental water damage that is covered by your home insurance.

Benefit from personalized advice

Do you have questions about your home, need specific information, or are you looking for referrals to find an Approved Supplier?

To contact our Residential Advisory Services
1-877-803-1118