Why Everyone in Ottawa Is Talking About Radon Testing Right Now (And You Should Too)

If you have never tested your Ottawa home for radon, October is the right time to start.

A long-term radon test needs to run for at least 90 days. Starting in October means your test will cover the colder, closed-window months when homes are typically sealed and radon levels can be higher. You can then receive a more reliable picture of the air your family is breathing during the heating season.

Radon is a serious indoor air quality concern, but the solution is manageable. Test first, understand the result, and take professional action if needed.

What Is Radon and Why Does It Matter?

Radon is a radioactive gas created naturally when uranium in soil and rock breaks down. It can enter your home through:

Cracks in the foundation or basement floor
Floor-to-wall joints
Sump pits and basement drains
Crawl spaces
Gaps around pipes and utility penetrations
Dirt floors
Well water in some situations

Radon is invisible, odourless, and tasteless. You cannot detect it by walking into a room or opening a window. A home can look clean, well-maintained, and completely normal while still having elevated radon levels.

Outdoors, radon is diluted by the open air. Indoors, especially in a basement or lower level, it can accumulate. When you breathe radon decay products over a long period, radioactive particles can damage lung tissue and increase the risk of lung cancer.

The good news is simple: testing is the only way to know your home’s level, and testing is straightforward.

Why Are Ottawa Homeowners Paying More Attention to Radon?

Ottawa homes can be exposed to radon because of naturally occurring uranium in the soil and underlying rock. However, levels can vary significantly from one neighbourhood and property to another.

That means your neighbour’s result cannot tell you what is happening in your home.

Older homes may have more foundation cracks, aging floor drains, or unfinished basement areas where soil gas can enter. Newer homes can also have elevated radon levels, particularly when construction makes the building more airtight without providing enough fresh-air exchange.

You should be especially motivated to test if:

You live in an older home built before the 1980s.
Your home has a basement, crawl space, or slab-on-grade foundation.
You have recently completed renovations that changed airflow or ventilation.
Your family spends several hours a day in the basement.
You have never completed a radon test.
You are buying, selling, or building a home in the Ottawa area.

No home is automatically safe from radon based on its age, location, or appearance. Measurement, not guesswork, is the only reliable answer.

Why Is October the Best Month to Start a Radon Test?

So, you’ve discovered that radon is invisible and that levels can vary from home to home. When should you test?

Start in October if possible.

Health Canada recommends a long-term test lasting at least three months. October is an ideal starting point because the test will run through the heating season, when:

Windows and exterior doors are usually kept closed.
Furnaces and heating systems operate more often.
Indoor and outdoor air pressure differences can draw soil gas into the home.
Families spend more time indoors.
Natural ventilation is reduced.

Think of it like checking your home during its most realistic high-use period. A summer test with windows open may not represent the conditions your family experiences in January or February.

October is not the only acceptable month to begin. However, it gives you a practical opportunity to measure your home during the closed-window months and receive your results early in the new year.

It is a simple step, but timing makes the result more useful.

How Does a Three-Month Radon Test Work?

A long-term test measures the average radon concentration in your home over a minimum of 90 days. The device is placed in an appropriate location, left undisturbed, and then sent to a laboratory or reviewed according to the monitor’s instructions.

For the most meaningful result, place the detector:

On the lowest level of your home that you regularly occupy
In a bedroom, family room, or other lived-in area
Away from windows, exterior doors, vents, fireplaces, and direct sunlight
Away from kitchens, bathrooms, laundry rooms, and high-humidity areas
At least some distance from the floor, following the device instructions

If your basement is unfinished and rarely used, the main floor may be the correct testing location. If you regularly spend time in a basement family room or bedroom, that lower level may be more appropriate.

The test should remain in place for the full testing period. Do not move it from room to room, and avoid changing the conditions around it unnecessarily.

You can choose a do-it-yourself kit or hire a certified professional. A DIY kit can be a practical option when you carefully follow the instructions. A professional radon measurement service adds accurate placement, equipment guidance, documentation, and help interpreting the result.

Explore our radon testing and measurement services in Ottawa or review our radon measurement products.

What Does 200 Bq/m³ Mean?

Health Canada’s guideline for indoor radon is 200 becquerels per cubic metre (200 Bq/m³).

A becquerel is a measure of radioactive activity. In everyday terms, the result tells you how much radon is present in the air over time.

Long-term test result	What you should do
Below 200 Bq/m³	Continue sensible home maintenance and consider retesting after major renovations or changes to ventilation.
At or above the guideline	Speak with a qualified radon professional about the result and appropriate next steps.
Significantly above 200 Bq/m³	Arrange mitigation promptly, particularly if the level is substantially elevated or your family spends considerable time in the affected area.

A high result can feel alarming. The good news is that elevated radon is a fixable indoor air quality problem. You do not need to move out or panic. You need a properly planned solution.

What Happens If Your Radon Level Is High?

If your long-term test shows elevated radon, the most reliable solution is usually a radon mitigation system. In many homes, this involves sub-slab depressurization.

Think of the system like a controlled exhaust route beneath your home. Instead of allowing soil gas to enter through cracks and openings, the system draws radon from beneath the slab and directs it safely outdoors through a vent pipe.

A professional mitigation assessment considers:

Your foundation type
Basement or crawl-space construction
Sump pits and floor drains
Cracks and other entry points
The location of occupied rooms
Your measured radon concentration
The best route for the venting system

Health Canada reports that a properly installed mitigation system can reduce radon levels substantially, often by more than 80%. After installation, the home should be retested to confirm that the system is working effectively.

Visit our radon mitigation services page to learn more.

Sealing cracks and improving ventilation may help as supporting measures, but these actions are not a standalone solution for a high radon result. Radon needs to be measured, controlled, and verified.

What Does the Ontario Building Code Change Mean for New Homes?

Radon is also receiving more attention because of a recent Ontario Building Code change.

Since April 1, 2025, the 2024 Ontario Building Code has required new homes and qualifying Part 9 residential construction to include a radon rough-in for a future subfloor depressurization system. The rough-in typically includes components such as a pipe beneath the slab and construction measures designed to help control soil gas.

This does not mean every new home automatically has low radon.

A rough-in makes future mitigation easier if post-occupancy testing identifies elevated levels. You should still test a new home after moving in, because the only way to know the actual indoor concentration is to measure it.

If you are building or buying a new home, ask:

Was a radon rough-in installed?
Where is the capped pipe located?
Was the soil-gas barrier properly installed and sealed?
Has the completed home been tested for radon?

The building code provides an important foundation. Testing confirms the result.

Should You Test This October?

Yes, especially if you have never tested.

Start your long-term radon test now so it can run through the winter. Keep the device in place for at least 90 days, follow the instructions carefully, and review the result when the test is complete.

If you prefer professional assistance, our team can help with radon testing in Ottawa, equipment placement, measurement, reporting, and mitigation recommendations. We provide clear advice without unnecessary alarm, so you can make a confident decision for your home and family.

For additional guidance, review:

Radon is invisible, but your next step does not have to be complicated. Test this fall, understand your result, and take action if needed. That is the clearest path to safer indoor air and peace of mind for your family.