After radon mitigation the retest that checks the fan
A system that pulls under the slab and exhausts above the roof lowers radon while the fan runs and the pipe stays tight. A U-tube or manometer shows suction. It does not show becquerels per cubic metre.
The check is a new test in the same room as before the work, the lowest lived-in room, for 91 days, during the heating season. A two-day reading on installation day answers a deadline. It does not replace the season. In the 2012 survey protocol, Health Canada asked people to act within two years between 200 and 600 Bq/m³ and within one year above 600. The retest says whether the action was enough.
When to do it again
Retest after an addition, a new basement floor, or a replaced fan. The usual cadence is in how often to retest. Switching the fan off in summer “to save power” puts soil gas back in play as soon as the house closes up.
Price is a different page
What changes the price. How the pipe is routed.
The 4-day test is a first reading. The 91-day test is the length Health Canada uses to judge a heating season. Both are $59 before tax. Shipping, the prepaid return and the lab are included. Tax is extra. The PDF report is emailed within 2 business days after the lab receives the detector.
Above 200 Bq/m³, the fix is a fan that pulls soil gas from under the slab and exhausts it above the roof. Gaz Radon is C-NRPP certified for testing and for mitigation, and ships kits across Canada. Start from the Canada test page.
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