Most homeowners have heard of mold. Fewer have heard of radon, and that's a problem: Health Canada names it the second-leading cause of lung cancer after smoking. Radon is a naturally occurring radioactive gas that seeps up from the ground. It has no smell, colour or taste. You can't tell it's there without a test.
Metro Vancouver isn't a radon hotspot the way parts of the BC Interior are, but lower risk isn't no risk. Radon levels vary from house to house depending on the foundation, the soil and how airtight the home is. The only way to know your levels is to test.
What is radon, and why does it matter?
Radon forms from the natural breakdown of uranium in soil and rock. It enters homes through foundation cracks, sump pits, gaps around pipes and other openings where the house meets the ground. Once inside, it can build up, especially in basements and lower floors with little air exchange.
Health Canada's guideline sets the action level at 200 Bq/m³ (becquerels per cubic metre) as an annual average. Above that, Health Canada recommends reducing the level. The higher the level and the longer the exposure, the greater the health risk.
Why Vancouver homes aren't automatically safe
A few local factors are worth knowing:
- Older housing stock. Many Vancouver and Fraser Valley homes have basements or crawlspaces with foundation cracks or unsealed penetrations, which are easy entry points for soil gas.
- Tighter building envelopes. Renovations and energy-efficient construction add insulation and air sealing, so less outdoor air mixes with indoor air. That helps heating bills, but it can also let radon build up instead of dissipating.
- Lot-to-lot variation. Radon potential can change from one lot to the next within the same neighbourhood, depending on the geology underneath. A neighbour's clean test tells you nothing about your home.
When you should test
- Before buying a home, especially one with a basement, crawlspace or slab-on-grade foundation.
- Before selling. A clean radon test gives buyers confidence and removes a negotiation point.
- After a major renovation. Air sealing, new windows or a finished basement can change how air moves through the house.
- In a new build. Tighter modern construction doesn't guarantee low radon. It changes how the gas behaves once it's inside.
- Every few years as routine maintenance, since levels can shift with seasons and changes to the house.
How radon testing works
Short-term tests (2 to 7 days) give a quick snapshot and are useful during a real estate purchase. Long-term tests (91 days or more) give a more accurate annual average, because radon levels change with weather, ventilation habits and seasons. Foxhound can add radon testing to your home inspection, so you get the building's condition and its radon results from one visit.
If your levels come back high
A high reading doesn't mean you need to move. The most common fix is a sub-slab depressurization system, which draws gas from under the foundation and vents it outdoors. It's a well-established method, and a certified mitigation contractor can usually bring levels well below the action level.
The bottom line
Radon is easy to overlook because you can't see, smell or feel it. That's exactly why a test beats intuition. Whether you're buying your first home, listing a property or just want to know what your family is breathing, a radon test is a small cost with long-term value.
Book a home inspection with radon testing with Foxhound Inspections, serving Metro Vancouver and the Fraser Valley, or call 604 779 3043.