Question 1

What is radon?

Accepted Answer

Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil and bedrock. It is colourless, odourless and tasteless, so it can only be detected with a test. Health Canada identifies radon as the second leading cause of lung cancer after smoking, responsible for roughly 3,200 lung-cancer deaths in Canada every year.

Question 2

What is radon gas and where does it come from?

Accepted Answer

Radon gas (Rn-222) is produced by the radioactive decay of radium, which itself comes from uranium in soil and rock. Outdoors it dilutes harmlessly in the air, but it can seep into a home through cracks in the foundation, floor-wall joints, sump pits, floor drains, construction joints, and gaps around service pipes. Once inside an enclosed space it can build up to dangerous levels.

Question 3

Is radon a problem in Windsor-Essex and Southern Ontario?

Accepted Answer

Yes. Cross-Canada surveys by Health Canada have found elevated radon in every region, and Windsor-Essex sits on bedrock and glacial soils that can release radon. Roughly 1 in 5 homes tested in Ontario exceeds the Health Canada action level of 200 Bq/m³. Newer homes are not exempt — tighter building envelopes can actually trap more radon indoors.

Question 4

What is a radon detector and which kind should I use?

Accepted Answer

A radon detector measures the concentration of radon in the air. There are two broad types: passive detectors (alpha-track or activated charcoal) that you place for 91+ days and mail to a lab, and active electronic continuous radon monitors (CRMs) that give hourly readings. For a result you can act on, Health Canada recommends a long-term test of at least 3 months — ideally during the heating season.

Question 5

Are DIY radon test kits accurate?

Accepted Answer

Yes — when you use a C-NRPP-approved long-term alpha-track kit and follow the instructions (correct location, undisturbed for 91+ days, returned promptly to the lab), DIY kits are accurate enough to make decisions on. Short-term charcoal tests (2–7 days) are more variable and should only be used for screening or real-estate timelines, ideally followed by a long-term test.

Question 6

Where can I get a radon test kit?

Accepted Answer

You can buy long-term radon test kits from Canadian Lung Association affiliates, Take Action on Radon, most major hardware retailers, and directly from C-NRPP labs. They typically cost $30–$60 with lab analysis included. We also provide professional measurement services using continuous radon monitors if you need faster, certified results.

Question 7

How do I test for radon — what is the right process?

Accepted Answer

Place the detector in the lowest lived-in level of the home (basement rec room or main floor if there is no basement), at least 50 cm from exterior walls and 150 cm above the floor, away from drafts, heat and humidity. Keep the home in normal closed-house conditions: windows closed except for routine entry/exit, HVAC running as usual. Leave it in place for at least 91 days, then send it to the lab.

Question 8

What is a radon mitigation system?

Accepted Answer

A radon mitigation system is permanent equipment installed in a home to reduce indoor radon to a safe level. The most common design is active soil depressurization (ASD): a sealed PVC pipe is run from beneath the basement slab up through the building and out above the roofline, with a continuously running inline fan that pulls radon-laden soil gas out before it can enter the home. Properly designed systems routinely reduce radon by 80–99%.

Question 9

How does radon mitigation work?

Accepted Answer

It works by reversing the air-pressure relationship between the soil and the house. The fan creates a slight negative pressure under the slab, so soil gas (including radon) follows the path of least resistance — up the mitigation pipe and out above the roof — instead of leaking through cracks into the basement. Sealing of major entry points (sump lid, large slab cracks, floor-wall joint where appropriate) supports the suction and improves performance.

Question 10

How is a radon mitigation system installed?

Accepted Answer

A C-NRPP-certified mitigator performs a building inspection and diagnostic measurements, cores a 4–5 inch hole through the basement slab and excavates a small suction pit, runs sealed 4-inch (100 mm) PVC pipe up through the house (often through a closet or utility chase) and out above the roofline, installs an exterior or attic-mounted radon fan above all living space, adds a manometer to confirm the system is running, seals major radon entry points, and finally performs a post-mitigation radon test to verify the result.

Question 11

Can I install a radon mitigation system myself (DIY)?

Accepted Answer

Technically you can — but Health Canada and the C-NRPP strongly recommend hiring a certified mitigator. Poorly designed DIY systems often discharge radon too close to windows, use undersized fans, or place fans in the basement (which can pressurize and leak radon back into living space). A certified install includes diagnostics, post-mitigation verification, and warranty. If radon is a real health hazard, treating it like a roofing job is the wrong tradeoff.

Question 12

What does a radon mitigation fan do, and how long does it last?

Accepted Answer

The radon fan is the heart of the system: a quiet, continuously-running inline fan that creates suction in the under-slab pipe network. Typical fans draw 40–90 watts continuously and last 10–15 years. Replacement is straightforward and usually costs $150–$400 in parts plus labour. The fan is always installed outside the building envelope or in a vented attic so any leaks discharge outdoors, never into the home.

Question 13

How much does a radon mitigation system cost?

Accepted Answer

In Windsor-Essex and across Southern Ontario, a typical residential radon mitigation system costs between $2,300 and $3,800 installed. The range depends on the home's foundation type (poured slab vs. block, slab-on-grade, crawlspace), the routing of the pipe through the house, the fan size required, and whether you choose an exterior or interior pipe run. Complex homes (multiple slabs, additions, deep crawlspaces) can cost $4,500–$6,000+.

Question 14

How much does a radon test cost?

Accepted Answer

A C-NRPP-approved DIY long-term test kit costs roughly $30–$60 including lab analysis. A professional measurement using a continuous radon monitor (CRM) — typically used for real-estate transactions or quick screening — costs about $150–$300 for a short-term test, or $300–$500 for a longer placement with a written report.

Question 15

How do I choose a radon mitigation company?

Accepted Answer

Hire only mitigators certified by the Canadian National Radon Proficiency Program (C-NRPP). Ask for the certification number, proof of liability insurance, a written scope of work, a post-mitigation test included in the price, and a warranty on the system and fan. Avoid anyone who quotes without inspecting the home or who refuses to do verification testing.

Question 16

Are there rebates for radon mitigation in Ontario?

Accepted Answer

There is no province-wide rebate program in Ontario as of 2026, and the federal Canada Greener Homes program does not currently cover radon mitigation. Some municipalities have run pilot rebates — check with your local public health unit. Take Action on Radon and the Canadian Lung Association also occasionally run subsidized testing campaigns.

Radon questions, answered straight.

Radon basics

Testing & detection

Radon mitigation systems

Cost & companies

Still have questions about radon in your home?