Your long-term test came back over 200 Bq/m3, and the basement is where the kids sleep. Before you call anyone for a quote, it’s worth knowing what a radon mitigation system actually is, because once you understand the pipe, the fan and the little U-tube on the wall, the quotes stop sounding like a sales pitch and start sounding like plumbing.
Nearly every system installed in a Prairie house uses the same design: sub-slab depressurization, also called active soil depressurization. A pipe goes through the basement floor, a fan pulls air from under the slab, and that air is vented outside. That’s the whole idea. The details are where one job differs from the next.
A quick word on units. Radon is measured in becquerels per cubic metre (Bq/m3). Health Canada’s guideline is 200 Bq/m3, averaged over a year, in the part of the house someone uses four or more hours a day. That’s about 5.4 pCi/L if you’re comparing against American figures. It is a guideline, not a law: neither Manitoba nor Saskatchewan requires homeowners to test or to fix anything.
So why bother? Health Canada says radon is the number one cause of lung cancer in non-smokers and the second leading cause overall, linked to more than 3,000 lung cancer deaths in Canada each year. That’s the reason. We’ll leave it there and get practical.
What a radon mitigation system does under your floor
Health Canada explains the problem as a pressure difference. The air pressure inside your home is usually lower than in the soil around the foundation, so the house draws soil gas in wherever it can. The usual entry points are cracks in the floor and walls, construction joints, gaps around service pipes, floor drains, sumps and cavities inside walls. You can’t see, smell or feel any of it.
A sub-slab system turns that around. The fan makes the pressure under the slab slightly lower than the pressure in your basement, so gas under the floor heads for the pipe instead of your rec room. Health Canada describes it as reversing “the air pressure difference between the house and soil.”
How much does it help? Most of Health Canada’s pages say a system will cut radon by more than 80% in most homes. Its September 2026 factsheet on reducing radon puts it at 90% or more. Those are Health Canada’s general figures, not a forecast for your house, and nobody can honestly promise you a post-mitigation number before the system is in and tested.
For comparison, Health Canada says balanced ventilation (an HRV or ERV) generally reduces radon by only 20% to 50%. When a big reduction is needed, active soil depressurization is almost always the recommended approach.
No result yet? Test first. A long-term test of at least 91 days in the heating season is the number a mitigation professional should be designing around. Call (204) 555-0173 or send us a note, and we’ll point you toward a long-term test. There’s more on how to run one on our radon testing page.
The parts of a sub-slab depressurization system
A system looks simple once it’s on the wall, but each part has a job, and a good quote will explain every one of them.
The suction point is a hole cored through the concrete slab into the crushed rock or soil underneath. Most houses need one. Some need several, depending on what’s under the floor and how the basement was built, and that is a judgment a professional makes on site, not over the phone.
The pipe, usually PVC, runs from the suction point to the fan and then outside. Its route depends on your walls, ceilings and finished rooms. In a finished basement the installer may need to go through a closet, a utility room or a bulkhead.
The fan runs 24 hours a day. Health Canada’s 2014 guide is blunt about this: the fan should never be turned off, because the system only works while it runs.
The discharge is where the gas leaves the house. Health Canada says a fan installed indoors is usually vented sideways through the rim joist at ground level, while a fan in a garage or attic is typically vented up above the roof. That choice matters on the Prairies. Health Canada notes that a fan and pipe outside the living space will cool in winter, which leads to condensation and possibly ice that can damage the fan. Putting the fan indoors with a shorter pipe discharging near ground level reduces that problem.
Sealing comes next. An open sump gets an airtight cover, and if the sump also works as a floor drain, a trap goes in the cover so it can still drain. Cracks and gaps around pipes are sealed so the fan isn’t just pulling basement air. Health Canada is clear that sealing on its own is not a standalone fix. We cover lids and traps in more detail in radon sump pit sealing.
The manometer is a small U-tube gauge on the pipe, with coloured liquid inside. When the fan is pulling, the liquid sits at different heights on each side. If the two sides are level, something has stopped working. Our post on reading a radon manometer shows what normal looks like.
How a radon mitigation system goes in on install day
Health Canada says a system can usually be installed in less than a day. That’s the working day on site, after a visit and a quote.
The installer looks at the foundation first: where the sump is, which rooms are finished, where the furnace and water heater sit, and which outside wall makes sense for the discharge. Then they core the slab, which takes a concrete coring drill. This is specialist equipment and it’s one reason this is not a weekend project.
After the pipe and fan are in, the fan needs power. How that’s handled varies by house, so ask the quote to spell it out. Before the installer leaves, the system should be checked so it doesn’t cause backdrafting of combustion appliances. Health Canada names furnaces, water heaters, fireplaces and wood stoves. A system that pulls exhaust back into the house has created a new problem.
Health Canada recommends using a C-NRPP certified mitigation professional. C-NRPP is the Canadian National Radon Proficiency Program, run by CARST with Health Canada oversight. It’s voluntary: no province regulates radon professionals, so certification belongs to the individual who quotes and does the work. You can check a name in the C-NRPP directory before you sign anything.
What a radon mitigation system costs to install and run
No city has a single “price” for a system. What exists is what individual installers advertise. Winnipeg installers advertise systems from about $1,500 to $3,000; a Regina installer quotes $2,500 to $3,500. We found no published price from an installer in Saskatoon, Brandon, Moose Jaw or Prince Albert, so if you live there, treat the Winnipeg and Regina figures as a reference point, not a local rate.
| Item | Figure (CAD, tax excluded) | Source and scope |
|---|---|---|
| Installed system, Winnipeg | about $1,500 to $3,000 | Advertised by Winnipeg installers |
| Winter install, Winnipeg | extra 20%, 30 Nov to 20 May | One Winnipeg installer’s advertised off-season charge |
| Installed system, Regina | $2,500 to $3,500 | One Regina installer; crawl spaces or multiple suction points “could be much higher” |
| Installed system, national | $2,000 to $3,000 | Health Canada, 2014 |
| Replacement fan | $200 to $300 | Health Canada, 2014, national |
| Fan electricity | about $50 to $75 a year | Health Canada, 2014, national |
The fan figures are old national estimates. Nobody has published a current Prairie fan price or a Manitoba Hydro or SaskPower running cost that we could find.
Some help exists. The Canadian Lung Association’s Lungs Matter program offers up to $1,500 to households with income below the provincial median. It needs a C-NRPP test of 90 days or more showing over 200 Bq/m3, a quote from a C-NRPP professional, and it won’t cover work already done. Funding is limited. In Manitoba, the Manitoba Lung Association runs it, and Manitoba Hydro’s Home Energy Efficiency Loan covers radon mitigation up to $5,000 over five years at 6.2% (O.A.C.), paid on your energy bill, with a C-NRPP certified contractor.
In Saskatchewan, Lung Saskatchewan has offered reimbursement in the past; check its site for the current status. Lung Saskatchewan also says radon mitigation counts as an eligible expense under the Saskatchewan Home Renovation Tax Credit, but confirm that with CRA before you count on it. There is currently no federal radon tax credit that we could find. For more on the numbers, see our radon mitigation cost page.
Three Prairie houses, three different installs
These are composite examples to show how the design changes with the house. They are not real customers.
Take a 1962 bungalow in St. Vital with a finished basement bedroom and an open sump in the utility room. The long-term test came back over the guideline. Here the sump is both a leak and an opportunity. Health Canada describes capping and sealing a sump so it keeps draining water and also serves as the suction point. If a floor drain connects to it, a trap seal is needed. With the fan in the utility room and a short run out through the rim joist, the pipe stays warm and out of the bedroom. The Winnipeg advertised range of about $1,500 to $3,000 is the reference point. If the owner books between 30 November and 20 May, one Winnipeg installer adds 20%, so ask about that before picking a date.
Now a 2015 Winnipeg build with a capped radon rough-in pipe that was never activated. Manitoba adopted the rough-in requirement on 1 April 2011, and it’s commonly a 100 mm pipe below the basement floor, sealed and labelled. The building code itself says the rough-in “does not actively reduce radon levels.” Someone still has to add a pipe route to the outside and a fan. The pipe also tells you nothing about the level in the house, so test first. And don’t assume it’s easy to reach: a 2013 study of Winnipeg Parade of Homes houses found rough-ins in all but one, with “almost half” in inaccessible locations. Whether the rough-in lowers the price is something only a site visit and quote can tell you. Our post on radon rough-ins in new homes goes further.
Last, a library radon monitor reading 480 Bq/m3 in a Regina rec room after a three-week loan. That’s worth taking seriously. Among the Regina homes tested in the 2024 Cross-Canada survey, 46.6% came in at or above 200 Bq/m3. But a three-week digital monitor is a screening tool, not a result to design a system around. The next step is a long-term test of at least 91 days. If that confirms a high level, a Regina installer quotes $2,500 to $3,500, and says crawl spaces or multiple suction points can cost much more. In Saskatoon, by comparison, roughly 1 in 6 tested homes in the same survey were at or above 200, which is lower, but it isn’t zero.
Have a high long-term result? Call (204) 555-0173 and we’ll put you in touch with a C-NRPP certified mitigation professional who can look at your basement and quote the job. Prefer to write it down? Use the contact form. You can read how the process works on our radon mitigation page.
After the install: retesting, the manometer and the fan
A system isn’t finished when the installer packs up. Health Canada’s current advice has three steps.
First, once the system is on, a certified professional should do a short-term test to confirm the level is below the guideline. Second, during the first heating season, do a long-term test in the same spot as your original test. Third, inspect the system regularly and retest every five years. You should also retest after an energy retrofit, since tightening a house can change how air moves through it.
Between tests, glance at the manometer now and then. Uneven liquid means the fan is pulling. Level liquid, a new rattle or a fan that has gone quiet all mean it’s time to have it looked at. Health Canada’s 2014 guide says a fan lasts five to ten or more years. If yours is noisy or dead, our radon fan replacement page explains what’s involved.
One more thing: don’t switch it off to save a few dollars on power, and don’t unplug it because the hum bothers you in winter. A system that isn’t running is just a pipe.
Frequently Asked Questions
Does a radon mitigation system have to run all the time?
Yes. Health Canada says the fan should never be turned off, because the system only reduces radon while it’s running. Its 2014 national estimate for fan electricity is about $50 to $75 a year, depending on the fan and your energy rates.
Can I install a radon mitigation system myself?
No law in Manitoba or Saskatchewan stops you, but Health Canada recommends a C-NRPP certified mitigation professional. The job involves coring concrete, sealing the sump correctly and checking for furnace or water heater backdrafting. Lungs Matter and the Manitoba Hydro loan both require C-NRPP, so a DIY install also rules out that help.
Does sub-slab depressurization work with a crawl space or a sump pit?
Health Canada says installers adapt the system for a slab, a crawl space or a sump pit, and a sealed sump can serve as the suction point. Crawl spaces and multiple suction points usually mean more work, and a Regina installer says those jobs can cost much more than the standard range. A site visit is the only way to know.
Can I open windows or run a basement fan instead?
Neither is a fix for a high result. Health Canada says balanced ventilation generally reduces radon by only 20% to 50%, and that active soil depressurization is almost always the recommended approach when a large reduction is needed. Whatever you try, a long-term retest is the only way to know where you stand.