Kamloops sits in one of British Columbia's higher-radon regions, and as the heating season arrives each fall, it becomes the single most important time of year to think about the air inside your home. Radon is a naturally occurring radioactive gas that seeps up from the soil and rock beneath a building. You cannot see it, smell it, or taste it — but Health Canada identifies it as the second-leading cause of lung cancer after smoking. For Kamloops homeowners, fall is when radon levels tend to peak and when testing gives the most reliable reading, so it is the right moment to understand the risk and what construction solutions actually work.
Why Kamloops Has a Radon Problem
Radon comes from the natural breakdown of uranium in soil and bedrock. The Thompson-Okanagan and the broader BC Interior have geology that produces more radon than coastal regions, and the BC Lung Foundation's testing data consistently places Kamloops-area homes among the higher-reading communities in the province. It is common for homes here to test well above Health Canada's guideline of 200 becquerels per cubic metre (Bq/m³) — and some come back several times higher.
The gas enters through the parts of your home in contact with the ground: cracks in the foundation slab, gaps around plumbing and service penetrations, sump pits, unfinished crawl spaces, and the joint where the slab meets the foundation wall. In winter, when your home is sealed up and warm air rises and escapes through the upper floors, it creates a slight vacuum at the basement level that actively draws radon-laden soil gas indoors. That "stack effect" is exactly why fall and winter readings in Kamloops are the ones that matter.
Testing First — It's Cheap and It's the Only Way to Know
Two identical houses on the same Kamloops street can have completely different radon levels, so you cannot predict your result from a neighbour's. Testing is the only answer, and it is inexpensive.
- Long-term test kits (91 days or more) are the gold standard and cost roughly $40 to $60. Because they run through the heart of the heating season, they capture your true average exposure. Order one in September or October and you will have a solid result by winter's end.
- Short-term tests (a few days to a week) run $30 to $50 and are useful for a quick screen — for example, before a real estate closing — but they are far less reliable and should be confirmed with a long-term test.
- Professional measurement by a C-NRPP-certified measurement professional typically runs $150 to $300 and is worth it when you are buying or selling, or want documented results.
Place the test in the lowest lived-in level of the home — a finished basement, a basement bedroom, or the main floor if you have no basement. If your long-term average comes back above 200 Bq/m³, Health Canada recommends you take action; above 600 Bq/m³, you should act promptly.
What Mitigation Actually Costs in 2026
The good news for Kamloops homeowners is that radon is very fixable, and the fix is a well-understood piece of construction. The most effective and widely used method is active sub-slab depressurization. A contractor cores a hole through the basement floor slab, installs a suction pit and piping, and connects it to a quiet, continuously running radon fan that vents the soil gas up through the roofline before it ever enters your living space. Done properly, this routinely cuts radon levels by 80 to 90 percent or more.
Realistic 2026 costs in the Kamloops area:
- A standard active sub-slab system: roughly $2,500 to $4,500 installed, depending on foundation type, the number of suction points needed, and how the vent stack is routed.
- Homes with a crawl space that needs sealing with a sealed membrane and sub-membrane depressurization: often $3,500 to $6,500.
- Sealing work alone (caulking slab cracks, sealing the sump, closing service gaps): a few hundred dollars, but on its own it rarely brings high readings down enough — it is a supporting measure, not a standalone fix.
- Post-mitigation re-test: budget another $40 to $60 to confirm the system worked.
A follow-up test after installation is not optional. It is how you prove the system is doing its job, and any reputable contractor will expect you to run one.
Building New in Kamloops? Radon Is Already in the Code
If you are building a custom home in Kamloops, the BC Building Code already requires radon protection. New homes must include a radon rough-in: a gas-permeable layer under the slab, a sealed soil-gas barrier, and a capped vent pipe run from beneath the slab up through the roof. This "passive" system sometimes reduces radon on its own, and it makes activating a full system later — by simply adding an in-line fan — dramatically cheaper than retrofitting an occupied home.
We always recommend Kamloops clients go one step further and have the rough-in installed so that adding a fan is a half-day job rather than a floor-coring project. It is a small cost during construction that can save thousands down the road, and it fits naturally alongside the air-sealing and ventilation work required under the BC Energy Step Code. In a tightly built, energy-efficient Kamloops home, good radon control and good ventilation go hand in hand — the tighter the envelope, the more deliberate you have to be about managing soil gas and fresh air.
Permits, HRVs, and Getting It Right
Most radon mitigation retrofits in a single-family Kamloops home are straightforward, but the electrical connection for the radon fan should be done to code, and any structural or significant alteration may involve a City of Kamloops permit — your contractor can confirm what your specific job requires. If your home has a heat recovery ventilator (HRV), balancing it correctly also helps, though an HRV alone will not solve a high radon reading; it is a complement to a proper depressurization system, not a substitute.
The most important thing is to work with someone who understands soil-gas dynamics and will test, mitigate, and re-test rather than just installing a fan and hoping. A system that lowers your reading from 500 to 450 is a failed system, even if it looks finished.
Take the First Step This Fall
Radon is one of the few serious home-health risks that is invisible, common in Kamloops, and completely fixable once you know it is there. Fall is the ideal time to start a long-term test, and if your results come back high, mitigation is a proven, affordable piece of construction — not a renovation nightmare. Whether you are retrofitting an existing home, planning a basement development where radon control matters most, or building new and want the rough-in done right, our team can help you plan the work and get it inspected and tested properly. [Request a free estimate from Hodder Construction](https://www.hodder.ca/estimate) and let's make sure the air in your Kamloops home is as healthy as it should be.