Radon mitigation across Southwestern Ontario, and the test to prove it.
Radon is the leading cause of lung cancer among people who do not smoke, and you cannot see it, smell it or taste it. We design and install the system that removes it from your home, then we test to show you where your level ended up.
You have the number. We are the fix.
Most people reach us after a test comes back over Health Canada's 200 Bq/m3, or after a neighbour's did. You do not need to wade through the science or wait on another round of testing to get moving. You need it fixed, verified, and off your mind, and that is the entire job.
You already tested
Bring us the number. We design the system to your result and your home, and the post-install test proves where you finished.
Your neighbour tested
Same soil and the same era of construction, but radon varies house to house. A high result next door is a real reason to act, not a guarantee your home is also high. Our guarantee is an absolute number rather than a percentage reduction, so it still means something without a "before" reading.
You are buying or selling
A radon result on a conditional does not have to derail the deal. We handle the fix and give you the documentation the transaction needs, and we run short-term tests for transactions on a timeline.
How can South West Radon help?
Three ways in, depending on where you are. If you already have a high reading, you want mitigation. If you do not have a number yet, you want a test. And if you intend to do the work yourself, you can buy an hour of a certified professional's time rather than guess.
Radon Mitigation
An engineered system that pulls radon out from under your home before it gets in, then a test that proves it worked.
- Sub-slab and sump pit systems
- Crawl space and stone foundations
- Guaranteed below 75 Bq/m3 or ALARA
- Post-install verification included
Radon Testing
Certified short-term testing for real estate transactions, plus the long-term kits and monitors we recommend to homeowners.
- 48-hour and 7-day certified tests
- Calibrated Corentium Pro device
- Detailed hourly report
- Long-term kits and monitors
DIY Consultation
Doing it yourself? Book time with a C-NRPP professional so the system you build actually works and does not create a new problem.
- Virtual or on-site
- System design guidance
- Backdrafting and safety review
- Honest answers, no upsell
What is radon, and why does it matter in Ontario?
Radon is a colourless, odourless radioactive gas produced as uranium breaks down in the ground. It seeps up through foundations and collects in basements and lower levels. Health Canada identifies it as the leading cause of lung cancer among people who do not smoke, and the only way to know your home's level is to measure it.
Canadians die each year from radon-induced lung cancer, more than carbon monoxide, car accidents and house fires combined.
of Ontario homes measured above the 200 Bq/m3 action level in the Health Canada Cross-Canada Survey, 2012.
Guelph homes tested above the action level, one of the highest rates recorded in Ontario (City of Guelph, 18 percent).
References: Health Canada, Radon · Take Action on Radon. Levels vary house to house, so a neighbour's reading is a reason to test rather than a substitute for testing. Last updated August 2026.
From radon number to a safe home in four steps
You want it fixed
Your test came back high, a neighbour's did, or a sale depends on it. Call us with your number, or without one.
Site inspection
A paid, educational walkthrough of your home with a certified professional. You get your options explained and a firm written price, and the fee is credited back in full if you proceed.
One-day install
A typical residential system goes in within a day, clean and tidy, with the vent routed properly to the exterior.
Verified below the limit
We run a post-install test and hand you the reading that proves where your home landed.
What makes a radon system worth paying for?
Any contractor can put a pipe through a slab. What separates a system that works from one that only looks like one is the diagnostic work before it, the fan chosen for the result, and the test afterwards that either proves it or does not.
Diagnostics before design
We take pressure field extension measurements to find out how air actually moves under your slab. That is what decides where the suction point goes and which fan it needs. Skipping it is how a system ends up treating one corner of a basement.
An absolute guarantee
Below 75 Bq/m3, not a percentage reduction. A percentage is only meaningful if you trust the before reading. An absolute number is a promise you can check against the post-install test we hand you.
A documented result
You get a report of the measurements and the post-install reading. It is what proves the work, and it is the document you will want if you ever sell the house.
Sealing done for the right reason
Sealing cracks does not fix radon on its own and we will not sell it as if it does. It makes the installed system more efficient by stopping conditioned air being pulled out from under the home, which is a real benefit and a different claim.
Quiet, and out of the way
Fan noise and an ugly pipe are the two things homeowners regret. Routing and fan selection get planned with you at the walkthrough rather than decided on install day.
Local, and here afterwards
We are based in the region and the person who quotes your job is the person who installs it. If something needs looking at in three years, you are calling the same number.
Where do you install radon systems?
We cover the Waterloo Region and Wellington County: Kitchener, Waterloo, Cambridge and Guelph, plus the surrounding townships. Each city page covers what we actually run into there, because a 1960s Kitchener bungalow, a Cambridge stone basement and a new Waterloo build are three different jobs.
What homeowners in the region say
These are unedited Google reviews from homeowners we have worked with. Nothing here is written by us.
We recently moved to a new place, and decided to do radon mitigation after a few months of testing. We've had several other contractors through in the past few months, and South West Radon was by far the best experience overall. The entire process with South West Radon was outstanding. Phil took the time to do a thorough visit and consultation, explaining the options, steps, showed us examples of different units, noise level, etc., without any feeling of upselling or pushing. During the install, we discovered an issue with the layout of our home that required a modified plan, and they offered us several alternatives. Installation was quick, professional, and competitively priced. We've done continued testing and our radon levels have absolutely plummeted, and are comparable with outdoor ambient levels, with virtually no negatives like noise.
HillsideGoogle reviewWe have been so pleased with our decision to have contracted Phil and his team to complete our Radon Mitigation. Right from the start it was apparent that we were dealing with a knowledgeable professional that had all of the attributes of the ideal contractor. Phil provided a description of every step of the process necessary, answered all questions prior, during and after the job. On installation day he and his crew treated our home as if it was their own and made sure the job was done effectively and neatly. Our readings improved within hours of completion.
Dino GuerraGoogle reviewPhil and his team are the definition of class act! When I contacted him initially, he was patiently explaining of how we shouldn't rush our decision in mitigating and get proper testing for our finished basement. I am very impressed of his professionalism. When we finally decided to mitigate, he showed up early, explained everything that him and his team were going to do. Throughout the day he made sure we were properly informed of all the procedure, and he also cleaned up the house afterward as well. Our radon level now is like barely around 5 bq/m3. If you need someone to take care of your basement radon, contact Phil!
Michael SuryaGoogle reviewRadon mitigation FAQ
How much does radon mitigation cost?
A typical residential radon mitigation system in this area runs about $3,200 to $4,000. The number depends on the house rather than a price list: how the foundation is built, how well air moves under the slab, where the pipe can be routed and what fan the diagnostics call for. The site inspection produces a firm written price for your specific home before any work is booked.
Why do you charge for a site inspection?
Because it is a real assessment by a C-NRPP certified professional rather than a sales visit. You get a paid, educational walkthrough of your home, an explanation of your options, and a firm written price for the work. If you go ahead with the mitigation, the inspection fee is credited back in full against the job, so it ends up costing you nothing.
Do I need to test before you can fix it?
No. Most people come to us with a result already in hand and that is the most direct route, but you do not have to wait for one. Plenty of homeowners mitigate because a neighbour tested high, or simply because they want the protection in place. Because our guarantee is an absolute number rather than a percentage reduction, it still means something without a "before" reading: the post-install test shows exactly where your home has landed.
How long does the installation take?
A typical residential system is installed in a single day. More complex homes, a stone or rubble foundation, multiple slab areas or a crawl space that needs its own treatment, can run longer, and the site inspection tells you which one yours is before you commit.
Will the system need maintenance?
Almost none, and that is deliberate. The system is designed so you can forget about it: there is nothing to service, nothing to empty and nothing to schedule. The fan is the only component with a service life, which is why we specify a good quality one rather than the cheapest that meets spec. If one ever does fail it is a straightforward replacement. We suggest retesting every couple of years or after major renovations, simply because that is good practice.
How much will a system actually reduce my radon level?
Health Canada reports that active sub-slab depressurization reduces radon by more than 80 percent in most homes. In practice we see reductions of 90 to 97 percent on many installs. Rather than quote a percentage, we guarantee an absolute number: below 75 Bq/m3, well under the 200 Bq/m3 at which Health Canada recommends action, or as low as reasonably achievable (ALARA) where a building restriction physically prevents reaching 75.
What areas do you serve?
Kitchener, Waterloo, Cambridge and Guelph, plus the surrounding Waterloo Region and Wellington County townships. If you are just outside that and not sure, call and ask.
Do you offer radon testing as well as mitigation?
Yes. We run certified short-term tests for real estate transactions using a calibrated Corentium Pro, and we recommend long-term test kits and continuous monitors for homeowners who want their own reading. Post-install verification testing is included with every mitigation.
Book your site inspection
Tell us a bit about your home and your radon result, and we will book your site inspection: a paid, educational walkthrough with a C-NRPP certified professional, your options explained, and a firm written price. The fee is credited back in full if you proceed. Prefer to talk now? Call (519) 807-1995.
Book my site inspection
We reply the same day, most days.
Your home either has a radon problem or it does not. Both are worth knowing.
One conversation tells you which one you are dealing with and what it would take to fix. No pressure, no obligation.