Best Radon Testing & Mitigation in London

About Radon in London, Ontario

Last updated: March 2026

London is served by C-NRPP certified radon professionals listed on RadonFinder.ca. 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 16 of 6 professionals in London

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.

TestingMitigation
Basic

London, ON provider of accurate radon measurement, testing, mitigation, and consultation services. Committed to promoting healthy living through reliable results.

Testing

Guoyan Liu

London, ON
Basic

Provides accurate radon measurement, testing, and mitigation services in London, ON. Ensuring home wellness with reliable results and expert consultation.

Testing
Basic
4.2(11)Google
TestingMitigation
4.9(532)Google

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

TestingMitigation

Frequently Asked Questions: Radon in London

RadonFinder.ca lists C-NRPP certified radon testing and mitigation professionals serving London, Ontario. Browse the directory above to compare professionals by services offered, certifications, and reviews.
Most homeowners in Ontario pay between $1,800 and $3,200 for a complete radon mitigation system. Actual cost depends on your foundation type, home size, and the complexity of the installation. Request quotes from multiple professionals to compare.
London 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 for levels between 200 and 600 Bq/m³, and within one year if above 600 Bq/m³.
Yes. Health Canada recommends testing every home in Canada, regardless of age, construction type, or location. Radon levels vary from house to house — even neighbouring homes can have very different readings. A long-term test of at least 91 days during the heating season is the most reliable method.
The most common system is active sub-slab depressurization (ASD). A certified professional installs a pipe through your foundation slab connected to a fan that draws radon from beneath the home and vents it safely above the roofline. Installation typically takes one day.

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Radon Resources for London

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