Mold Remediation in Ontario
Mold remediation is the process of finding, containing, and removing mold growth from a home or building, then fixing the moisture problem that caused it in the first place. It's a different job from basic mold cleaning: remediation involves sealing off the affected area with plastic sheeting and negative air pressure, removing contaminated materials like drywall, insulation, or flooring, treating surfaces that can be saved, running air scrubbers and HEPA filtration to clear spores from the air, and confirming the job worked with a post-remediation inspection. We list 133 businesses in Ontario that offer this work, ranging from small local operators to larger restoration companies that also handle fire and flood damage.
When you're comparing companies, look for a few concrete things: a written scope of work with a fixed containment plan, IICRC certification (specifically the S520 mold standard), a clear explanation of how they'll test or verify the job is done rather than just "it looks clean," and a separate line item for fixing the underlying moisture source (a leak, poor ventilation, a grading issue). Be wary of anyone who wants to quote a price over the phone without seeing the space.
Our ranked guide to water damage restoration services scores providers on factors like certification, responsiveness, and documented outcomes, using the process explained on our methodology page, so you can shortlist companies faster instead of cold-calling a dozen numbers.
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All mold remediation, ranked by score and relevance
293 businesses. The order weighs each business's overall score by how much of its reviewed work is mold remediation, so a lower-scored specialist can rank above a higher-scored generalist. Filter and sort below, or open the full map view.
Enquiries from our forms may be passed to partner providers who can do the work. We may earn a referral fee, but our rankings and scores are based only on our published method, never influenced by fees.
Common questions about mold remediation
- How much does mold remediation cost in Ontario?
- Small, contained jobs (a bathroom or closet with limited growth) often run in the low hundreds to about $1,500. Larger jobs involving a basement, HVAC contamination, or structural removal can run several thousand dollars. Get a written quote after an in-person assessment, since price depends heavily on square footage and how much material needs to be removed.
- How do I know if I actually need remediation versus just cleaning?
- Small surface mold on a hard, non-porous surface (tile, glass) can often be cleaned with soap and water or a mild bleach solution. If mold covers more than about 10 square feet, has gotten into porous materials like drywall or carpet, or keeps coming back, you're into remediation territory and should get a professional assessment.
- What should I expect during the remediation process?
- Expect an initial inspection and moisture assessment, then containment of the work area with plastic sheeting and negative air machines before any demolition starts. Contaminated materials get bagged and removed, remaining surfaces are treated, and air scrubbers run for a period afterward. A reputable company will also identify and address the moisture source, not just the visible mold.
- How can I judge the quality of a remediation company before hiring?
- Ask whether their technicians hold IICRC S520 certification, whether they provide a written scope and containment plan, and how they verify the job is finished (visual inspection, moisture readings, sometimes third-party clearance testing). Companies that skip containment or can't explain their verification step are worth avoiding.
Guides to choosing mold remediation
- What mold remediation costs in Ontario and what drives the price
Typical mold remediation price ranges in Ontario, what pushes the cost up, and how to tell a fair quote from an inflated one.
- Mold health risks after water damage: what to watch for
What mold exposure after a water leak can mean for your health, who's most at risk, and when to get professional testing rather than guessing.