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. The 2024 Cross-Canada survey found about 13% of Ontario homes exceed the guideline.

Typical Mitigation Cost in Ontario

$2,200–$3,800

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 1–8 of 8 professionals in London

MITIGAIR

London, ON

5.0(3)Google

MITIGAIR, based in London, ON, designs and installs radon mitigation systems that draw radon from beneath a home's foundation and vent it outdoors. It also offers radon test kits and serves homes across the Province of Ontario.

TestingMitigation

(647) 237-4662Call View Profile

EXP Service Inc.

London, ON

4.2(11)Google

EXP Service Inc. is a C-NRPP certified radon testing and mitigation professional serving London, ON. They offer complete radon solutions from initial testing through to mitigation system installation.

TestingMitigation

(519) 963-3000Call View Profile

JAM (2005) Enterprises

London, ON

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

Testing

(519) 709-0673Call View Profile

T. Harris Environmental Management Inc.

London, ON

T. Harris Environmental Management Inc. is an environmental and occupational health and safety consulting firm in London, ON, serving industrial, commercial, institutional and residential clients. Its services include radon testing alongside asbestos, mould and indoor air quality assessments.

Testing

(519) 685-9048Call View Profile

VIP Properties Management Ltd.

London, ON

VIP Properties Management Ltd. is a residential property management and rental agency in London, Ontario that also offers repairs, maintenance and renovations. Its listing includes radon testing, with Yumeng Chen holding C-NRPP certification.

Testing

(226) 602-0018Call View Profile

Advanced Basement Systems

Chatham, ON

4.9(593)Google

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

TestingMitigation

(519) 351-3500Call View Profile

Radon Checks

St. Thomas, ON

Radon Checks is a C-NRPP certified radon testing professional serving St Thomas, ON. Their certified inspectors provide accurate radon measurements for homes and businesses.

Testing

(519) 495-2206Call View Profile

North Air Ventilation

Stratford, ON

Testing

View Profile

Local radon data

How common is high radon in London?

Lower

1 in 37

homes tested in the London area had radon above Health Canada's action level of 200 Bq/m³. Your home can be very different from its neighbours, so the only way to know your level is to test.

London

1 in 37

Ontario

1 in 7.6

Canada

1 in 5.6

Postal areas nearby with the highest estimates

76 homes tested in the 2024 Cross-Canada survey. Source: the RadonFinder.ca radon map of Canada, built on the 2024 Cross-Canada survey, Health Canada data and Statistics Canada census data.

Open London on the radon map

Test before you call a pro

Know your radon level in London first

A home monitor tells you whether you need mitigation at all, and later confirms it worked. Health Canada bases decisions on a 3-month average, ideally through winter.

Best Overall

Airthings Corentium Home

~$170–190 CAD C-NRPP tested

View on Amazon.ca

Newest Model

Airthings Corentium Home 2

~$230–250 CAD

View on Amazon.ca

Compare all detectors · As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.

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 $2,200 and $3,800 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 and 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.