How Long Does a Radon Test Take? Short-Term vs Long-Term Timelines
Ask “how long does a radon test take” and you’ll get two different answers, because there are two different clocks. One clock is how long the device sits in your home. The other is how long until you hold a real number.
A short-term device can finish its run in 2 days. But you might wait another week or two for the lab result. A long-term test is the opposite. The device runs for 91 days, then the report comes back fast.
Here’s the honest breakdown of both clocks, so you can plan around whichever test fits your home.
The short version:
- A short-term test runs 2 to 7 days. Real estate tests can finish in 48 to 72 hours.
- A long-term test runs 91 days or more. It’s the number Health Canada trusts most.
- The device run time and the “when do I get my result” time are two separate things.
- DIY kits add 1 to 2 weeks of mail-in and lab time after the run ends.
- A continuous monitor shows a first reading in a day, with no lab wait.
- We hand you a written report within a few days of picking up the device.
The two clocks: run time vs result time
Most confusion comes from mixing up two things. Let’s split them.
Run time is how long the device measures the air. This is set by the test type. You don’t get to shorten it.
Result time is how long until you actually know your number. For DIY kits, that includes mailing the device to a lab and waiting for analysis.
A DIY charcoal kit might run for 3 days. Then you mail it. Then the lab reads it. You could wait 10 to 14 more days for the email.
A pro test skips most of that wait. The device is dropped off, picked up, and the report is written for you. No trip to the post office on your end.
Short-term radon test: 2 to 7 days
A short-term test is the fast option. It gives you a screening number in under a week of run time.
Health Canada sets the floor at 48 hours. Anything shorter isn’t valid.
Here’s what the short-term clock looks like:
- Run time: 2 to 7 days in the lowest level you live in
- Closed-house setup: windows and outside doors shut for 12 hours before you start
- DIY result time: add 1 to 2 weeks for mail-in and lab analysis
- Pro result time: a written report within a few days of pickup
Short-term tests are a snapshot. They tell you if your home is probably fine or probably high. They swing more with weather, so they’re a first screen, not the final word.
Real estate radon test: 48 to 72 hours
Buying or selling a home puts you on a deadline. You can’t wait 91 days when closing is 2 weeks out.
A real estate radon test runs 48 to 72 hours under strict closed-house rules. It’s built for transaction timelines.
This test uses a continuous monitor set to a locked protocol. The house stays closed the whole time. That keeps the reading conservative and defensible for the deal.
Our real estate test is $399 with a 48 to 72 hour turnaround. You get a signed report you can hand to the other side of the deal. If you’re buying, our buyer’s playbook for radon tests covers the clause wording and timing.
Long-term radon test: 91 days or more
Here’s the twist. The longest test gives the fastest result once it’s done.
A long-term test runs for at least 91 days.
Why so long? Because radon levels swing a lot. They rise in winter and fall in summer. A 91-day run averages those swings out.
Health Canada calls the long-term test the best way to decide whether to fix your home.
If you want the most trustworthy single number, this is it. We break down the full process in our guide to long-term radon monitoring in Ontario.
Why longer tests are more accurate
A short test is like checking the weather once. A long test is like tracking the climate.
Radon comes up from the soil. In winter, warm air rises inside your house and pulls soil gas up through the basement. This is the stack effect.
Closed windows and a running furnace trap that gas inside. So winter readings run higher than summer ones. We cover this in detail in our post on why radon spikes in winter.
A 2-day test in July can miss a real winter problem. It might read low while your true yearly average is well above the guideline.
The tradeoff is simple. Short tests are fast but noisy. Long tests are slow but steady.
How long until you get your result
Run time is only half the story. Here’s the full timeline for each option, start to finish.
| Test type | Device run time | Extra wait for result | Total time to your number |
|---|---|---|---|
| DIY charcoal (short-term) | 2 to 7 days | 1 to 2 weeks (mail + lab) | About 2 to 3 weeks |
| DIY alpha track (long-term) | 91+ days | 2 to 4 weeks (mail + lab) | About 3.5 to 4 months |
| Continuous monitor (own) | First reading in 24 hrs | None | 1 day, stable by day 7 |
| Pro short-term test | 2 to 7 days | A few days | Under 2 weeks |
| Pro real estate test | 48 to 72 hrs | A few days | Under 1 week |
| Pro long-term test | 91 days | 1 to 2 weeks | About 3.5 months |
The pattern is clear. DIY kits cost less but add mailing and lab time. Pro tests and monitors cut the wait.
DIY kit vs hiring a pro: which is faster for you?
A DIY kit works fine for most homeowners with no deadline. A pro test is worth it when the clock matters. Here’s the honest split.
When DIY makes sense
You own your home. You’re curious. You have no deadline.
Buy a long-term alpha track kit for about $40. Leave it out for 91 days. Mail it in. You’ll have your number in roughly 3.5 months, and it’ll be a solid one.
DIY works because the lab process is the same one a pro uses. The chemistry doesn’t care who dropped the kit off.
When to book a pro instead
Some situations call for a certified test with a fast, signed report.
- Buying or selling. Your closing date is weeks away. A pro short-term or real estate test fits the window.
- Filing a Tarion warranty claim. Tarion needs a certified measurement, not a mail-in slip.
- Confirming mitigation worked. The check-up test after a system goes in should be independent.
- You tested high once already. A second test by a different method removes doubt before you spend on a fix.
The middle path: a continuous monitor
A $250 monitor shows a first reading in a day. No lab. No mailing. It keeps reading month after month.
Once you own one, you never buy another kit. For families with kids in basement bedrooms, it’s often the right call.
How our timeline works
We use continuous monitors for every Breathe Radon Free test. That cuts the wait on your end.
Here’s the flow. We drop off the device. It runs for the set time. We pick it up and write your report.
- Residential test: $99 flat. Runs 2 to 7 days. Written report within a few days of pickup.
- Real estate test: $399. Runs 48 to 72 hours. Fast report for closing deadlines.
- Long-term test: $299. A 91-day run for the most reliable yearly average.
You reach a co-founder, not a call centre. Every test follows Health Canada protocol. Radon is the second-leading cause of lung cancer in Canada, so getting the number right matters more than getting it fast.
Book a radon test in 60 seconds.
Frequently asked questions
How long does a radon test take, start to finish?
It depends on the test. A DIY short-term kit takes about 2 to 3 weeks total, counting mail-in and lab time. A pro short-term test gives you a report in under 2 weeks. A long-term test runs 91 days plus a week or two for the lab. A continuous monitor shows a first reading in 24 hours.
What is the minimum time for a radon test?
Health Canada requires at least 48 hours for a valid short-term measurement.
How long does a radon test for real estate take?
A real estate transaction test runs 48 to 72 hours under closed-house conditions. You get a signed report within a few days. It’s built to fit the inspection window in a home sale.
Why does a long-term radon test take 91 days?
Radon levels swing with the seasons and the weather. A 91-day run averages those swings out, so the number reflects your real yearly exposure. Health Canada considers it the best basis for deciding whether to fix your home.
Can I get radon results the same day?
Only with a continuous monitor you own. It shows a live reading within 24 hours and a stable average after about a week. Mail-in kits always add lab time, so same-day results aren’t possible with them.
Get a radon test booked in 60 seconds →
Authored by the Breathe Radon Free Team. Every claim is backed by a primary source. Full bibliography at /sources.
Ready to test your home?
Get a quote in 60 seconds. Published prices, no sales follow-up.