Did a long-term radon test in our 1965 Toronto bungalow after reading about Health Canada’s updated guidelines. Result came back at 185 Bq/m3 - below the 200 action level but above Health Canada’s 100 reference level. Sharing the whole process.
Why We Tested
Our house sits on a street in the Humber Valley area where one neighbour mentioned elevated results. Bought a Corentium long-term alpha track detector ($48 from Costco), placed it in the basement office (lowest occupied level) for 11 months.
The Result
185 Bq/m3. Not technically requiring remediation at Canada’s 200 threshold, but above the 100 WHO/Health Canada reference level and concerning given we work from home in that basement.
What We Decided
Given we spend 6-8 hours/day in the basement, we decided to install active sub-slab depressurization (ASD) rather than wait and see.
The Mitigation Work
Contractor: certified by C-NRPP (Canadian National Radon Proficiency Program)
Scope:
- Core drilled through basement floor in two locations (slab + soil communication confirmed with smoke test)
- 3-inch PVC pipe run up through utility room and out through rim joist
- Radon fan (RadonAway GP301) installed in conduit in utility room
- Sealed floor core holes with hydraulic cement + polyurethane caulk
Cost: $2,100
Post-Mitigation Test (3 months)
Re-tested with Corentium for 3 months: result 18 Bq/m3. Reduction from 185 to 18 = 90% reduction.
Highly recommend testing if you haven’t. Test kits are $30-$50. The peace of mind is worth it regardless of result.