Radon Professionals in Ontario

About Radon in Ontario

Last updated: March 2026

Ontario has widely varying radon risk depending on geography. The Ottawa Valley, eastern Ontario, and areas underlain by the Canadian Shield — including parts of Sudbury, Elliot Lake, and the Bancroft region — have elevated radon due to uranium-rich granite bedrock. Southern Ontario's clay and limestone geology generally produces lower levels, though local hotspots exist in any region. Health Canada estimates roughly 7% of Ontario homes exceed the guideline.

Typical Mitigation Cost in Ontario

$1,800–$3,200

Near national average

Costs vary significantly between the GTA, Ottawa, and northern Ontario due to labour markets and home construction types.

  • •Foundation type — poured concrete, block, or slab
  • •Basement finish level — unfinished installs are faster and cheaper
  • •Pipe routing complexity in finished or split-level homes
  • •GTA vs. rural Ontario labour rate differences
  • •Age of home — older homes may require additional sealing work

Showing 1–15 of 80 professionals in Ontario

Kingston Radon Solutions

Glenburnie, ON
Basic
5.0(54)Google

Locally owned & operated, C-NRPP certified, offering radon testing, mitigation & DIY solutions. Installs Airwell™ systems for radon & other contaminants. Serving Kingston, Napanee, Gananoque, Belleville & surrounding areas.

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Radon Hero

Ottawa, ON
Basic
5.0(10)Google

C-NRPP certified professional radon testing & mitigation services in Ottawa. Offers a risk-free guarantee: don't pay until radon levels are below 100 Bq/m³.

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Custom Build Standard Construction Corp.

Richmond Hill, ON
Basic
4.8(46)Google

Full-service construction company specializing in custom homes, multiplexes, and renovations. Offers framing, structural steel, insulation, and drywall services in Toronto & the GTA.

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Mr. Radon

Greenbank, ON
Basic
4.9(27)Google

Family-owned & operated since 2005, providing radon testing & mitigation services throughout Ontario. Guarantees include lowering radon levels & cleanliness.

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613environmental

Kinburn, ON
Basic
5.0(21)Google

Offers C-NRPP certified radon gas measurement and mitigation, from testing to custom system installation with guaranteed results. Serving Ottawa and Eastern Ontario.

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MITIGAIR

London, ON
Basic
5.0(3)Google

Provides radon mitigation services throughout the Province of Ontario. Certified Professional Mitigators design and install systems to extract radon and minimize its concentration.

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Mr. Radon Inc.

Greenbank, ON
Basic
4.9(27)Google

Family-owned and operated since 2005, providing radon testing and solutions throughout Ontario. Guarantees to lower radon levels below 100Bq/m³ and ensures a clean worksite.

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Rival Home Inspections

Ajax, ON
Basic
5.0(190)Google

Offers radon services. Serves Ajax, ON, Toronto, Durham, York, Peel, Halton, Simcoe, Brant, Dufferin, Kawartha Lakes, Hamilton, Waterloo, Peterborough, and all GTA Regions.

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Radon Safe Northwest Ltd.

Thunder Bay, ON
Basic
5.0(1)Google

Certified provider of radon gas measurement and mitigation services in Thunder Bay and surrounding areas.

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Michèle Légaré

Ottawa, ON
Basic
5.0(45)Google

Offers comprehensive radon testing and mitigation services in Ottawa, ON. A 5-star rated service with experienced, licensed technicians providing customized systems.

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Stephen Vares

Thunder Bay, ON
Basic
5.0(1)Google

Certified radon gas measurement and mitigation provider in Thunder Bay, ON. Services the city and surrounding areas for homeowners concerned about radon gas.

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Basement Boss

Neustadt, ON
Basic
5.0(4)Google

Provides radon measurement & mitigation services throughout Southwestern Ontario.

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Advanced Basement Systems

Chatham, ON
Basic
4.9(532)Google

Offers radon mitigation inspection and services to reduce hazardous radon levels for homeowners in Southwestern Ontario, including Chatham.

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South West Radon Pros Inc.

Kitchener, ON
Basic
5.0(44)Google

Offers C-NRPP certified radon testing, mitigation, and DIY fix solutions. Serving Kitchener, Waterloo, Cambridge, Guelph, and surrounding areas, they guarantee reduced radon levels in residential settings.

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Barrhaven Home Inspectors, Inc

Ottawa, ON
Basic
4.9(41)Google

Licensed and certified experts offer radon and IAQ analysis in the Ottawa area.

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Browse by City in Ontario

Top cities by professional count

Radon mitigation in Ottawa, Ontario
9 local professionals listed
Radon mitigation in London, Ontario
4 local professionals listed
Radon mitigation in Mississauga, Ontario
4 local professionals listed
Radon mitigation in Thunder Bay, Ontario
3 local professionals listed
Radon mitigation in Kitchener, Ontario
3 local professionals listed
Radon mitigation in Guelph, Ontario
3 local professionals listed
Radon mitigation in Markham, Ontario
3 local professionals listed
Radon mitigation in Greenbank, Ontario
2 local professionals listed
Radon mitigation in Stoney Creek, Ontario
2 local professionals listed

Other areas with radon professionals

Sault Ste MarieBurlingtonTorontoSt. ThomasEtobicokeBarrieGlenburnieRichmond HillKinburnAjaxNeustadtChathamNew DundeeKingstonRussellCharing CrossGananoqueNepeanWaterlooTecumsehKomokaNorth YorkElliot LakeVaughanPickeringWhitbyAlmonteMitchellOrleansTilburyShannonvilleHamiltonBramptonPetawawaDundas, Ancaster, BurlingtonCarleton PlaceKenoraOrangevilleSt. CatharinesKemptvilleSudbury

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Frequently Asked Questions: Radon in Ontario

Ottawa, Kingston, Sudbury, and communities in the Ottawa Valley and Canadian Shield region tend to report higher radon levels. However, localized hotspots can exist anywhere in Ontario, so testing is recommended province-wide.
Radon testing is not legally required in Ontario real estate transactions, but it is increasingly common in home inspection agreements, particularly in Ottawa and the surrounding region where awareness is higher.
Ontario follows Health Canada's national guideline of 200 Bq/m³. If your home tests above this level, Health Canada recommends taking action to reduce radon within two years (or sooner if levels are very high).
The Canadian Shield's granite and gneiss bedrock contains naturally elevated uranium concentrations, which decay into radon gas. Homes built directly over or near Shield geology — particularly in eastern and northern Ontario — face a higher risk of elevated indoor radon.
Health Canada recommends a long-term test of at least three months, conducted in the lowest livable area of the home during the heating season (fall through spring) when windows and doors are kept closed most of the time.
Units on upper floors of high-rise condos are generally at low risk because radon dissipates quickly above grade. Ground-floor units and basement suites are more susceptible and worth testing. Townhouse-style condos with basements should always be tested.
Use the city search above to find certified radon professionals serving your area. All listings on RadonFinder.ca hold current C-NRPP certification.
Most Ontario homeowners pay between $1,800 and $3,200 for a complete active sub-slab depressurization system. Ottawa homes with complicated configurations or multiple entry points may reach the higher end of this range.

Radon Resources for Ontario

Tools and guides to help you understand radon risk and take action.

Check your radon risk
Estimate your risk based on province, home age, and foundation type.
Understand your test results
Learn what Bq/m³ means and when action is required.
DIY radon test kits
Compare test kit options starting from $10.
Radon guides & articles
In-depth guides on testing, mitigation, and health risk.
Browse all provinces
Find certified professionals anywhere in Canada.
Radon FAQ
Answers to the most common questions about radon.