Radon questions answered

Remediation, mitigation, removal: are they the same thing?

Yes. All three mean lowering the radon in your home with a system. Installers say mitigation. There is no way to remove radon from the ground; the system keeps it out of the house.

Is radon mitigation loud?

The fan runs all the time and makes a low hum close to it. Installers put it in a utility room, an unfinished part of the basement, an attached garage or the attic, away from bedrooms.

How long does a test take, and when?

A long-term test runs for 91 days or more, best between October and April. A short-term test of a few days is a screen, not a number to decide on.

Is radon testing free?

Usually not. A kit costs about $50 with the lab fee. In Thunder Bay, free health unit kits were one-off studies in 2014 and 2017. Library detectors are free to borrow. EcoSuperior

Is there a radon map of Thunder Bay?

The ward table on our Thunder Bay page is the closest thing. It comes from the health unit's 2014/15 study of tested homes, ward by ward, from McIntyre at 43% down to Westfort at 0%. Two homes on the same street can still test differently, so the table tells you to test, not to skip it.

What radon level is safe?

Health Canada's guideline is 200 Bq/m3 as a yearly average. Between 200 and 600, fix it within two years. Above 600, within one year. Lower is always better. Health Canada

I am buying a house. Can I ask for a test?

Yes. Ask the seller for a long-term result if they have one. If not, a short-term test can be done before closing as a screen, with a long-term test after you move in. For a new build, see the next question.

Does my new build have a radon system?

Probably not. Since April 1, 2025, the Ontario Building Code requires a radon rough-in in new houses, which is a capped pipe under the slab. It is not a working system. Test the house. If the result is high, Tarion's warranty covers radon in homes under seven years old. HCRA

How do I check an installer is certified?

Ask for the C-NRPP number and look it up. Every installer we work with is listed there. C-NRPP certification check

Will sealing cracks fix it?

On its own, no. Health Canada says sealing entry routes helps, but how much depends on how high your level is. Sealing is part of a system, not a replacement for one. Health Canada

Does a radon system help with moisture or smells?

Often the basement feels drier, because the system also pulls damp air from under the slab. We do not promise that. The system is for radon.

When should I retest?

Right after a system goes in, to confirm it works. Then within five years, and after any renovation that touches the foundation or the heating system.

How much does it cost?

Your installer gives you a written quote before any work starts, and the quote depends on the house. We do not publish prices on this site.