Specialist confirmation

    Radon Testing & Mitigation

    Radon cannot be seen or smelled, and levels vary house to house. Health Canada recommends long-term testing to establish a level for a specific home.

    Quick Overview

    Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil and rock. It seeps into homes through foundation cracks, floor drains, and construction gaps — and accumulates in basements.

    Present in:All Canadian provinces
    Health risk:High
    Health Canada limit:200 Bq/m³

    How to Identify Elevated Radon

    • • Purchase a long-term alpha track test kit at hardware stores
    • • Place detector in lowest occupied level for minimum 91 days
    • • High-risk: basements of older homes with exposed soil, floor drains, sump pits
    • • Higher risk geology: granite bedrock, marine shale, glacial till
    • • High-risk provinces include Manitoba, Saskatchewan, New Brunswick, Ontario (Bancroft area)
    • • Radon has no smell, colour, or taste — testing is the only detection method

    Major Risks

    • • Health Canada identifies radon as a leading cause of lung cancer in Canada after smoking
    • • Risk generally increases with concentration and duration of exposure
    • • Basement levels are typically higher than outdoor air
    • • Smokers with elevated radon exposure face a compounded risk of lung cancer
    • • Often no symptoms — lung cancer may not appear for many years
    • • Radon can enter homes of any age or foundation type — testing is the only way to know your level

    Budgeting for Testing and Mitigation

    Long-term test kit (DIY):Check retailer pricing
    Professional radon test:Ask for a written quote
    Sub-slab depressurization (ASD):Get itemized contractor quotes
    HRV/ERV upgrade (supplemental):Get itemized contractor quotes
    Post-mitigation follow-up test:Ask for a written quote

    Costs vary by scope, region and contractor — collect written quotes from C-NRPP certified contractors before deciding.

    Professional Recommendations

    Immediate Actions:

    • • Purchase a long-term alpha track test kit and place in the basement
    • • Test for at least 91 days during the fall/winter heating season
    • • Keep windows closed during the test for accurate results
    • • Seal visible foundation cracks and floor drain gaps as a first step

    If Levels Exceed 200 Bq/m³:

    • • Hire a C-NRPP certified radon mitigation contractor
    • • Sub-slab depressurization (ASD) is the most effective solution
    • • Retest 24 hours post-installation, then again after 30 days
    • • Ensure your mitigation contractor provides a written post-mitigation test

    Look for C-NRPP certified professionals in your area — certification can be verified through the Canadian National Radon Proficiency Program. Always verify contractor certification before hiring for mitigation work.

    Radon Resources & Tools

    Specialized radon testing, mapping, and mitigation resources for Canadian homeowners.

    RadonAbatement.ca

    Radon abatement resources

    RadonDetectors.ca

    Radon detector guides

    RadonFan.ca

    Radon fan & ventilation

    RadonInspectors.ca

    Certified radon inspectors

    RadonLab.ca

    Lab testing & analysis

    RadonMap.ca

    Canadian radon zone mapping

    RadonRisk.ca

    Radon risk assessment

    RadonSpecialists.ca

    Mitigation specialists

    RadonSystem.ca

    Mitigation systems

    Common questions

    Frequently Asked Questions About Old Canadian Houses

    Common questions from buyers and owners of older Canadian homes, answered with era context and pointers to the professionals who can confirm anything on a specific property.

    Have a question not answered here? Browse our full inspection guide or explore all resources.