Radon testing in Calgary

Why test for radon in Calgary?

Because testing is the only way to know a home's level, and elevated results are common in this region. The 2024 Cross-Canada Survey of Radon Exposure found about 1 in 6 houses in the Calgary area at or above 200 Bq/m³source. An earlier University of Calgary-led study, published in 2017, measured 2,382 homes in Calgary and the surrounding area and found about 1 in 8 at or above Health Canada's guidelinesource. Levels differ from one house to the next, even between neighbours on the same street, so a result from next door says little about yourssource. The studies behind these figures are summarized in our Calgary radon map and risk guide.

The age of the house is not a shortcut either. Research led by the University of Calgary found that radon in newly built Canadian houses has been rising since about 1980source. Alberta's building code requires a radon rough-in, a capped pipe stub through the slab, in new homessource, but that pipe does nothing until a test shows it is needed and a fan is connected. A new build in a young community and a 1960s bungalow both need a measurement before anyone can say what is in the air.

Should I choose a long-term or a short-term test?

Choose a long-term test whenever you have the time, because it is the one the guideline is built on. Health Canada recommends measuring for three to twelve months and treats 91 days as the minimumsource. Radon swings with weather, air pressure and how hard the furnace is working, and three months is long enough for those swings to average into a number that represents what the household breathes.

A short-term test usually runs for two to seven dayssource, and Health Canada does not recommend testing for periods under 91 dayssource. A short test answers a narrower question: what was the level in this room during these days? That is useful during a home purchase, as a first screen, or as a quick check that a new mitigation system is doing its job. It is not a sound basis for deciding that a home is fine for the next twenty years.

The device matters as much as the duration. For long-term tests Health Canada recommends two kinds of passive device, alpha track detectors and electret ion chambers, and electronic radon monitors are used as wellsource. An alpha track detector has no battery and no screen. It simply records radon decays on a small piece of film for as long as it is left out, and a laboratory reads it afterwards.

Is a professional test better than a DIY kit?

Not automatically. A long-term kit from a reputable laboratory, placed correctly and left alone for at least 91 days, produces a valid result, and for many households it is the right place to start. A professional test adds three things: placement by someone trained to do it, a documented chain from detector to report, and a person to explain the number and what follows from it. Health Canada recommends using professionals certified by the Canadian National Radon Proficiency Program (C-NRPP)source.

Tests arranged through Calgary Radon Pro are carried out by Plinio Neto, who holds the C-NRPP Radon Measurement Professional certification (CRT-202965). You can confirm it in the C-NRPP directory of certified professionals.

If a kit suits you, our page on radon test kits in Calgary covers the types and how to set one up.

What happens during a professional test?

Four things, and the homeowner's part is small.

1. Placement. The detector is set in the right room at the right height, and its serial number, location and start date are recorded.
2. Waiting. You live normally: usual heating, usual ventilation, usual comings and goings. The detector is not moved, covered or unplugged.
3. Collection. At the end of the test the detector is sealed and sent to the laboratory, or the monitor's data is downloaded.
4. Report. You receive the result in writing, with a plain explanation of what it means for your home and what, if anything, to do next.

For a short-term test the tester will usually ask that windows and outside doors stay closed apart from normal use, starting before the monitor is set and lasting until it is collected. A long-term test has no such condition, because its purpose is to capture the house exactly as it is lived in.

When is the best time to test in Calgary?

Start in the fall. Health Canada asks that at least 91 days of the test fall within the heating season, when windows are closed and indoor radon tends to be at its highestsource. A detector placed in October or November and collected in late winter sits entirely inside that window.

A test can begin at any time of year. One that starts in spring or summer just has to stay in place until it has collected its 91 days of furnace weather, which usually means leaving it out into the following winter. The practical advice is simple: if the heating season has started, start the test now and do not wait for a "better" month. Chinooks, cold snaps and holidays away are all part of how the house is really lived in, and a three-month test absorbs them.

Where should the detector go?

Health Canada's guide puts the detector in a room that is used for four hours a day or more, on the lowest lived-in level, roughly 30 cm or more above the floor and clear of walls, kitchens, bathrooms, laundry rooms, vents, heat sources, direct sunlight and electronicssource.

• Good spots: a basement bedroom, family room or home office, on a shelf or side table at breathing height.
• Poor spots: the furnace room, a cold storage room, a windowsill, the top of a television, or anywhere a pet or a child will move it.
• Basement not used: place it on the main floor, since the guideline follows where people spend their time.
• Basement suite, addition on its own foundation or split-level layout: a second detector is often justified.

Once it is placed, leave it. Write down the start date, the room and the detector's serial number on the day you set it out. Those notes are part of the result.

How long until I get results?

For a long-term test the wait is mostly the test itself: at least 91 days, then the laboratory's turnaround. For a short-term test with an electronic monitor, the readings exist the moment the monitor is collected, and the report is written from them.

A report should state the average concentration in Bq/m³, the start and end dates, the room and floor, the type of device and, for a monitor, the hourly readings. If any of those are missing, the number is harder to use later, for example when a buyer or an installer asks how it was obtained.

What do my results mean?

The Canadian guideline is 200 Bq/m³ as an annual averagesource, and that is the number a long-term result is compared with. Above it, Health Canada recommends reducing radon within one year, and sooner for higher resultssource. Below it the decision is yours: the recommendation to act starts above 200 Bq/m³, no level is risk-free and a lower one is always preferable.

A short-term result needs more care. Well above the guideline, it is a strong signal and worth acting on. Near or below the guideline, it tells you only that those few days were moderate. Our guide to radon levels and the Canadian guideline shows how quickly to act in each range, and the result checker converts and places a number for you.

What about testing when buying or selling a home?

Test before you sell, or after you buy. Health Canada does not recommend conducting a radon test during a real estate transaction, because only a three-month test finds a home's level accuratelysource. Its advice to buyers is a long-term test once they have moved insource. A short reading during a purchase is optional screening and never replaces that test.

The Real Estate Council of Alberta has issued radon guidance to its licenseessource, so most agents have met the topic. Sellers have an easier route: a long-term test started the autumn before a spring listing gives buyers a documented answer. Details are on our page about radon testing for Calgary real estate.

Do I need to test again after mitigation?

Yes. A system is judged by measurement, not by the fact that the fan is running. The installer's short reading after installation shows the system is pulling radon down. The new annual average comes from a long-term test in the next heating season, best done with a laboratory kit that the homeowner places and mails, so the confirmation is independent of whoever did the installation.

Health Canada recommends testing once a system has been installed, again every five years while it is in service, and after any renovation that changes the structure or ventilation of the homesource. Finishing a basement, adding an addition, replacing windows or changing the heating system can all shift how air and soil gas move through a house.

See post-mitigation testing for timing, and radon mitigation in Calgary for how the systems themselves work.

How much does a radon test cost?

The price of a professional test covers the detector or monitor, placement and collection, laboratory analysis or data download, and the written report. A do-it-yourself long-term kit costs less because you do the placing, the record keeping and the mailing. Either way, a test is a small part of what mitigation costs, and it is the step that tells you whether mitigation is needed at all. Our Calgary cost guide sets testing and system prices side by side.