Hiring a mould removal company in Toronto

What a mould removal listing does and does not record

On the site, the second most common category is mould removal. Among the 294 records, water damage restoration appears in 258, mould removal in 200, fire and smoke restoration in 78, mould inspection and testing in 59, basement flood cleanup in 37, and sewage backup cleanup in 30. Because a single record can belong to several of these categories at once, the category totals add up to more than the index: 151 listings have three categories, 66 have two, and 77 have one.

The meaningful difference is in the overlap within the mould group. A total of 200 companies offer mould removal. Of these, 175 also offer water damage restoration, and 49 also offer mould inspection and testing. Twenty-five carry mould removal with no water damage category on the record. For a homeowner whose ceiling stain appeared with a leak, that 25 is the group most likely to send the water problem back.

Each record also retains the business label assigned by Google Maps, within the site's own six categories. In the full index, that label is water damage restoration service for 211 companies, building restoration service for 29, environmental consultant for 14, asbestos testing service for 13, fire damage restoration service for 9, followed by a short tail of general contractors, plumbers, construction companies, home inspectors and remodelers. An environmental consultant and a water damage restoration service may both appear under mould removal but do quite different work once they arrive.

The category states what a company claims to offer. It does not show crew size, equipment, whether the labour is subcontracted, or how long the business has been trading. The index includes none of that for any of the 294 records.

The water repair sits on a separate line from the mould

Every published Toronto cost guide that supports this site's mould removal cost page splits out moisture repair as a separate scope. Rerouting a bathroom exhaust fan, waterproofing, regrading, and installing a backwater valve are quoted apart from the containment, tear-out, and antimicrobial work that make up remediation. A quote can be complete and correct without touching the cause of the mould.

The attic example reveals the usual pattern. Ultimate Mold Crew in Toronto lists bathroom exhaust fans venting into the attic among the common causes of attic mould, and counts exhaust fan rerouting among the extra work that adds to the attic price rather than part of it. If the sheathing is cleaned while the fan still vents into the attic, the growth comes back on the same timetable that produced it.

The basement version of the same problem is plumbing, not ducting. Premier Plumbing's 2026 Toronto guide puts the cost to install a new sump pump at $782 to $1,750, with most installations around $1,164. The City of Toronto's Basement Flooding Protection Subsidy pays toward that hardware, up to $6,650 per property for work completed on or after November 12, 2025, and none of it goes to mould removal; the per-item caps are on the basement flood cleanup cost page.

That is what the 175 figure means in practice. A company that carries both categories can assess the drying, the removal and the moisture repair in one visit, which does not lower the cost and does make the sequence easier to manage. The 25 mould-only listings and the water damage restoration side of the index require two separate calls.

Why two quotes for the same basement differ by thousands

Square-foot pricing across the GTA does not fit one range. CPR24 Restoration says Toronto cleanup companies usually charge $4.88 to $5.57 per square foot for standard removal and $13.93 to $41.80 for full service, and Ultimate Mold Crew puts professional remediation with air filtration and post-removal cleaning at $10 to $30 per square foot. Both are per-square-foot prices for mould work in the same city; what differs is the scope.

Project prices share the same range. For a small bathroom job, Restoration Mate puts mould removal at $1,000 to $3,000, and CPR24 Restoration puts small surface cleanups, especially in bathrooms, at $696 to $2,090. Restoration Mate puts basement mould remediation at $2,500 to $8,000, while The Mold Guy's 2026 Toronto guide puts whole-home remediation at $10,000 to $30,000 or more. Ultimate Mold Crew prices attic work separately, at $3.50 to $4.00 per square foot of attic floor.

How much of the affected material is porous and must be removed from the building, and how much containment the crew sets up before disturbing it, are the two factors that create the gap. If a quote does not specify either factor, it is not comparable to a quote that does. The scope of testing adds a third variable: Restoration Mate lists initial inspection and testing at $300 to $800, and The Mold Guy lists a post-remediation clearance test at $200 to $400.

The size of the patch decides whether anyone gets hired

Health Canada's residential guidance sets the boundary by area, not by species. A mould area is small if it consists of at most three patches that together cover less than one square metre, about 10.8 square feet, and if an occupant can clean it themselves with a disposable N95 respirator, safety goggles, household gloves, water and dish detergent. Health Canada states plainly that bleach is not needed. A qualified professional should assess and clean any single patch larger than three square metres. Many contractor pages repeat the 10 square foot figure, but that is the US EPA number; the Canadian threshold is metric.

The price split occurs at the same threshold. For a job smaller than one square metre, a complete kit that includes cleaner, N95 masks, gloves, goggles, poly sheeting and heavy garbage bags costs $60 to $150 at Home Depot Canada retail prices, with a 946 mL bottle of Concrobium Mold Control at $12.48 from Home Depot Canada and a ten-pack of 3M 8511 N95 respirators at $38.99 per United Canada Inc. Professional work starts well above that. Because of minimum call-out fees, almost no professional visit costs under about $500, and small area jobs run $500 to $3,000 per Ultimate Mold Crew.

The expensive mistake is about material, not square footage. Drywall, insulation and carpet padding with actual growth have to be removed rather than cleaned, and wiping their surfaces leaves the growth inside the cavity. Mold Inspection Canada sets the cost of that redo at $1,250 to $20,000 once drywall tear-out and remediation are required, with the usual range at $2,500 to $7,500. Running the DIY against professional comparison with the actual square footage and actual material is the step that determines whether any of the 200 companies needs to be called at all.

Ontario licenses none of this, so the checking falls to the buyer

No provincial licence exists in Ontario for mould remediation or water damage restoration. Any person can advertise the service, and the province does not certify, register or inspect the firms that do so. Instead, the industry relies on voluntary credentials: IICRC certification against the S520 mould remediation standard, the AMRT designation for mould technicians, the WRT designation for water damage. Health Canada's guidance takes a similar position: any indoor mould growth should be removed, and the moisture source should be fixed, but it sets no numeric safe exposure level for spores.

None of the 294 companies has certification, licence status, liability insurance or WSIB coverage recorded in this index. The index cannot record those details because Ontario has no public register for this trade that contains them. It records the company name, the area each company lists as its base, the categories it offers, the company's Google rating and review count when available, and a map position for all 294.

Before a contract is signed, two checks remain. The first is documentary: the certificate numbers, the insurance certificate, and the written scope that sets out the containment level, disposal, and how the moisture source will be handled. The second is structural: clearance testing carried out by a company other than the one that removed the material, since no one else in Ontario grades the work.

Where the mould removal companies are based

The listings are concentrated geographically. Of the 294 records, 38 are in Islington-City Centre West, 25 in Burlington, 19 in Willowdale, 17 in Don Mills, 15 each in Markham and Oakville, and 11 in Mississauga. Together, those seven areas contain 140 of the 294 listings, and mould removal firms show the same geographic pattern because 175 of the 200 also handle water damage work and the two categories share the same addresses.

Across the index, ratings are high and tightly bunched. Among the 277 rated companies, the mean is 4.76, the median is 5, and the range is from 1 to 5. The mould group differs little: 191 of the 200 mould removal listings have a rating, and those 191 average 4.82. The review counts behind those averages are small. Across the 277 rated companies, the combined number of reviews is 10,460, with a median of 19 per company and a maximum of 480, and 139 of the 277 have fewer than 20 reviews. When 197 of the 277 rated companies score 4.8 or higher, most of them on a handful of reviews, the rating no longer separates them, and the scope of the quote and the handling of the moisture source do the separating instead.