Introduction:

Homeowners in Ottawa take various steps to ensure their homes are safe — from installing smoke detectors and carbon monoxide alarms to inspecting for mold and asbestos. But there’s one invisible threat that often gets overlooked, despite being one of the leading causes of lung cancer in Canada: radon gas.

Radon is a naturally occurring radioactive gas that can accumulate in homes and buildings, especially in basements and lower floors. You can’t see it, smell it, or taste it — but it could be in your home right now.

If you’re asking, “How do I know if I need radon testing in Ottawa?” — the answer is almost always yes. But to make an informed decision, you need to understand what radon is, how it behaves, why it’s particularly problematic in Ottawa, and which homes are most at risk. For more info visit https://www.simonairquality.com/services/radon-testing/

What Is Radon and Why Does It Matter?

The Basics of Radon Gas

Radon is produced when uranium — found in soil, rock, and groundwater — breaks down naturally. As it decays, it releases radon gas, which can seep into homes through:

  • Cracks in foundations and basement walls
  • Gaps around pipes, sump pumps, and drains
  • Crawl spaces and unfinished floors

Once inside a building, radon becomes trapped, and its concentration can rise to harmful levels over time.

The Health Risk

Radon is a proven carcinogen. According to Health Canada and the World Health Organization:

  • It’s the second leading cause of lung cancer after smoking.
  • It causes about 3,000 lung cancer deaths each year in Canada.
  • Long-term exposure to radon significantly increases the risk of developing lung cancer — especially for smokers.

Radon is not a surface issue — you won’t see signs like cracks or stains. It’s airborne and only detectable through testing.

Why Is Radon Testing Crucial in Ottawa?

Ottawa’s Unique Risk Profile

Ottawa is one of the Canadian cities most affected by high radon levels due to:

  • Uranium-rich granite and shale bedrock
  • Clay-heavy glacial till soils, which trap and transport radon
  • Cold winters, which seal homes and limit natural ventilation

Because of these conditions, radon accumulates more easily and remains undetected in indoor environments. Studies show that 1 in 5 homes in Ottawa test above Health Canada’s recommended action level of 200 Bq/m³ (becquerels per cubic metre).

In some neighborhoods, more than 40% of homes have tested above this threshold.

So… Do You Need Radon Testing?

If you live in Ottawa or surrounding areas, you should test for radon — even if you believe your home is low-risk. But here are specific scenarios and risk factors that make testing essential.

1. You Live in a House With a Basement or Slab Foundation

Radon typically enters through the lowest part of the house. If your home has:

  • A full or partial basement
  • A crawl space
  • A slab-on-grade foundation

…then radon has a direct path into your living space.

Basements often lack ventilation, making them ideal for radon buildup — especially in finished basements where people spend time.

If you use your basement regularly, testing is even more important.

2. You’re Living in a Newer, Energy-Efficient Home

While newer homes are better insulated and sealed, this airtight construction can actually trap radon more effectively. Without natural airflow, radon builds up quickly — even in homes that meet modern building codes.

Health Canada has found that newer homes can have some of the highest radon levels, particularly in tightly sealed winter conditions.

Don’t assume your new home is safe — test to be sure.

3. You Spend a Lot of Time Indoors (Especially in Winter)

Ottawa experiences long, cold winters, during which homes are sealed tightly to conserve heat. This reduced ventilation can result in elevated radon levels.

If you:

  • Work from home
  • Have a home gym or office in the basement
  • Have children or elderly family members who stay indoors frequently

…you’re potentially being exposed to higher radon concentrations over time.

4. You’re Buying or Selling a Home in Ottawa

Radon is becoming a key consideration in real estate transactions. While not mandatory in Ontario, many buyers are requesting radon test results before finalizing deals.

Sellers who can show low radon levels (or proof of mitigation) often:

  • Close faster
  • Instill buyer confidence
  • Increase home value

If you’re buying, test to avoid a costly surprise later. If you’re selling, test to offer peace of mind.

5. Your Neighbor Had High Radon Levels

Radon concentration can vary dramatically from house to house — even on the same street. Factors include:

  • Soil composition beneath your home
  • Foundation type and condition
  • Ventilation systems

If your neighbor has high levels, it’s a warning sign — but it doesn’t guarantee your levels are the same.

You still need to test your own home.

6. You’ve Never Tested Your Home Before

Radon levels can change over time due to:

  • Soil moisture
  • Home renovations
  • HVAC system changes

Even if you’ve lived in your home for years without symptoms, that doesn’t mean you’re not at risk.

If you’ve never tested, especially in Ottawa, now is the time.

7. You Have a History of Smoking

Radon exposure multiplies the risk of lung cancer if you’re a smoker or ex-smoker. In fact:

  • A smoker exposed to 200 Bq/m³ has a 1 in 3 chance of developing lung cancer.
  • A non-smoker at the same level has a 1 in 20 risk.

If you or a household member smokes, radon testing becomes even more urgent.

How to Test for Radon in Ottawa

DIY Test Kits

Cost: $40–$80

Duration: At least 91 days for accuracy

Where to Buy: Hardware stores, online, or through Health Canada-approved labs

These kits include:

  • A passive radon detector (like an alpha track)
  • Setup instructions
  • A return envelope for lab analysis
  • Email or mail-in results

Professional Radon Testing

Cost: $150–$400

Equipment: Digital Continuous Radon Monitor (CRM)

Best for: Fast results, real estate, consultation

Certified Radon Pros in Ottawa:

  • Radon Works
  • Canadian Shield Radon
  • RadonCare
  • Healthy Home Center (Radon Ottawa)

Health Canada recommends long-term testing (91+ days) for reliable results, especially during the heating season (October–April).

Understanding Test Results

Radon Level (Bq/m³)Risk LevelHealth Canada Advice

0–99 Low No action required

100–199 Moderate Consider mitigation

200–600 High Fix within 2 years

600+ Very high Fix within 12 months

 

If you test over 200 Bq/m³, you’ll need to mitigate.

What If Your Test Shows High Levels?

Radon Mitigation Works — And It’s Permanent

The most common solution is a Sub-Slab Depressurization (SSD) system, which:

  • Installs a pipe through the foundation slab
  • Uses a fan to draw radon from beneath the home
  • Vents the gas safely outdoors

Cost: $2,000–$3,500

Effectiveness: Reduces radon by 90–99%

Time: Installed in 1–2 days

Noise: Quiet, low-maintenance fans

Re-testing after mitigation confirms the fix worked.

Ottawa Radon Statistics: Know the Numbers

  • Over 20% of homes exceed the safety limit of 200 Bq/m³.
  • In some neighborhoods, more than 40% of homes test high.
  • Radon is found in new and old homes alike.
  • Ottawa’s average is significantly higher than the national average (6.9%).

The bottom line? Don’t assume. Test.

Government and Community Support

Health Canada

  • Sets national radon guidelines
  • Lists certified labs and professionals
  • Offers free resources for homeowners

Take Action on Radon

  • National campaign offering free test kits in some Ottawa communities
  • Encourages long-term testing and awareness
  • Runs school and municipal outreach programs

Ottawa Public Health

  • Promotes radon education
  • Supports radon testing in schools and public buildings

Frequently Asked Questions (FAQs)

1. I live in a condo on the third floor — do I need to test?

Radon is usually concentrated at lower levels. If your unit is ground level or basement, yes. Otherwise, the risk is lower — but still possible depending on building design.

2. Will home insurance cover mitigation?

Typically not. However, some mortgage lenders and energy-efficiency programs offer incentives or rebates.

3. Should I re-test after renovations?

Yes. Major work that changes airflow or foundation integrity can affect radon levels.

4. Can I test in summer?

Yes, but winter testing is more reliable, since homes are sealed and radon concentrations peak.

Conclusion: Yes — You Likely Need to Test

If you live in Ottawa and haven’t tested your home for radon, the answer is clear: you need to. The city’s geology, construction trends, and climate create ideal conditions for elevated radon levels — and the health consequences are too serious to ignore.

Radon is invisible, but it is not invincible.

Testing is easy, affordable, and potentially life-saving. Don’t wait for symptoms. Don’t assume your neighbor’s test result applies to you. Take charge of your indoor air quality today and protect your health for years to come.