Black Mould Removal Toronto
Black mould removal Toronto homeowners search for usually follows the discovery of dark patches on a wall, ceiling or window frame, and the first question is whether it is dangerous.
Fully licensed and insured
Monday to Sunday: Open 24 hours
What "black mould" really means
Dark or black growth is common, and the colour is the part people notice, but colour does not tell you which species you have or how risky it is. Health Canada's guidance on moisture and mould indoors does not single out any colour. It says the risk depends on how much mould is growing, whatever the species, and it recommends cleaning up visible mould whatever type it is. We follow that approach: we treat dark growth like any other, by size, location and cause.
What does matter is how much there is, where it is and what it is growing on. A small spot on bathroom grout is a different job from dark staining spreading across a basement ceiling or the underside of attic sheathing.
Where black mould shows up in Toronto homes
In Toronto's older brick houses, dark growth often appears on basement walls, around the base of window frames and behind stored items against an exterior wall. In postwar bungalows and semis, it is common on ceilings below bathrooms and on the north side of closets. In newer houses and condominiums, it often forms behind furniture on cold exterior walls and around window sills where winter condensation collects.
After a flood or sewer backup, carpet underlay, baseboards and the bottom of drywall can turn dark within days if they are not dried properly. If a wet area was not opened and dried, dark growth in the cavity is likely even when the surface looks fine.
What to do and not do when you find it
- Do not scrub or disturb a large area, because that can spread material through the air
- Do not paint over it, because the growth continues underneath
- Do find and stop the water source if you can, for example a dripping pipe
- Do keep the area ventilated and keep children and anyone with breathing problems away
- Do photograph the area and call for an assessment
How we remove it
The process is the same for dark growth as for any mould. We inspect the area and the likely moisture source, seal the work area, filter the air, remove materials that cannot be cleaned and clean what can be, then dry the structure fully. A written scope and price come first, and the assessment is free.
Because Health Canada does not recommend routine air testing, we rely on a thorough visual inspection and moisture readings rather than on collecting samples. If you or your insurer need a particular report, ask us at the visit and we will tell you what we can provide.
Steps in a black mould job
- Call and describeTell us where the growth is and what has happened in that area.
- Free assessmentWe inspect and trace the water.
- Written scope and priceProvided before removal.
- Removal and dryingContainment, removal, drying and rebuild.
When the mould came from water: the City's flood protection subsidy
Black mould in a Toronto basement usually follows a leak or a flood, and removing it does not stop the water returning. The City of Toronto's subsidy program pays up to 80 percent of eligible protection work completed on or after 12 November 2025: a backwater valve up to 1,600 dollars (two at most), a sump pump and alarm up to 2,250 dollars, a battery backup up to 300 dollars, weeping tile capping up to 400 dollars and a plumbing assessment up to 500 dollars, with 6,650 dollars as the limit per property. These are the City's program limits, not our prices; our assessment is free and a written scope and price come before any repair work.
The program is for registered owners of homes with up to four units, and the contractor must hold a valid City of Toronto business licence. Funding is first come, first served.
Black mould questions
Is black mould more dangerous than other mould?
Health Canada's guidance does not distinguish by colour. It says risk depends on the extent of growth, and visible mould should be cleaned up whatever its type. If anyone in your home has symptoms, speak to their doctor.
Will bleach fix it?
Bleach on a surface does not address growth inside porous materials or the water behind it. Have anything larger than a small surface mark assessed.
How soon should I call?
Soon. Growth spreads while the moisture is present, and the affected area is easier to deal with when it is small.
Request a quote
Tell us what you need and we will get back to you. In a hurry? Calling is fastest.