Radon is one of those home hazards most people have heard about—but few truly understand. It’s invisible, odorless, and tasteless, yet it can pose a serious health risk when allowed to build up indoors. In a city like Ottawa, where climate, geology, and housing styles can all influence radon levels, many homeowners are left wondering: Do I actually need radon mitigation, or is this just another overblown home concern?
The short answer is: maybe—but there’s a clear way to find out.
This article walks you through everything Ottawa homeowners need to know about radon: what it is, why Ottawa homes can be vulnerable, how to test properly, how to interpret your results, and when mitigation is truly necessary. By the end, you’ll be able to make an informed, confident decision about your home and your family’s health.
What Is Radon and Why Should You Care?
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil and rock. Outdoors, it disperses harmlessly into the air. Indoors, however, it can become trapped and accumulate—especially in lower levels of a home.
The health concern comes from long-term exposure. According to Health Canada, radon is the second leading cause of lung cancer after smoking, and the leading cause among non-smokers. Thousands of radon-related lung cancer deaths occur in Canada every year.
What makes radon especially dangerous is that you won’t know it’s there unless you test. There are no symptoms, no smells, and no visible warning signs.
Is Radon a Problem in Ottawa?
Yes—radon is a known concern in Ottawa, though levels vary widely from home to home.
Ottawa sits on geological formations that can contain uranium-bearing rock and soil. When uranium decays, radon gas is released and can migrate upward through the ground. If your home has even small openings in the foundation, radon can enter and build up inside.
Areas With Higher Potential Risk
While radon levels are unpredictable on a house-by-house basis, elevated readings have been found in many parts of Ottawa and the surrounding region, including:
- Homes with full basements or crawl spaces
- Older homes with foundation cracks or stone foundations
- Newer, airtight homes with limited natural ventilation
- Properties built on certain soil types common in Eastern Ontario
Importantly, your neighbor’s test result doesn’t predict yours. Two identical homes side by side can have very different radon levels.
How Radon Gets Into Homes
Radon enters homes through contact with the ground. Common entry points include:
- Cracks in foundation walls or floors
- Gaps around pipes, sump pumps, or floor drains
- Construction joints
- Porous concrete blocks
- Crawl spaces with exposed soil
Once inside, radon can accumulate—especially during Ottawa’s long winter months, when windows stay closed and warm indoor air draws gases up from the soil below.
How to Know If You Need Radon Mitigation
You only need mitigation if your radon levels exceed recommended guidelines—and the only way to know that is through proper testing.
Step 1: Test Your Home
Radon testing is simple, affordable, and non-invasive. There are two main types:
Short-Term Tests
- Duration: 2–7 days
- Useful for quick screening
- Influenced by weather and ventilation
Long-Term Tests (Recommended)
- Duration: 90 days to 12 months
- Provides a more accurate yearly average
- Best reflection of actual exposure
Health Canada recommends long-term testing for the most reliable results, especially in climates like Ottawa’s where seasonal changes are significant.
Step 2: Understand Your Results
Radon levels are measured in becquerels per cubic metre (Bq/m³).
According to Health Canada guidelines:
- Below 200 Bq/m³: No immediate action required
- 200 Bq/m³ or higher: Radon mitigation is recommended
The higher the level and the longer the exposure, the greater the health risk. Even levels below 200 Bq/m³ may still be worth addressing if they are close to the guideline or if someone in the home is a smoker or has respiratory concerns.
Common Signs Your Home May Be More Vulnerable
While you can’t detect radon without testing, certain characteristics increase the likelihood of elevated levels:
- You spend a lot of time in the basement
- Your home feels “tight” with limited airflow
- You have visible foundation cracks
- Your home has a sump pit without a sealed cover
- You recently completed energy-efficiency upgrades
None of these guarantee high radon—but they make testing especially important.
What Is Radon Mitigation?
Radon mitigation refers to systems or techniques that reduce radon levels inside a building. The most common and effective solution for Ottawa homes is active soil depressurization.
How It Works
- A pipe is inserted through the basement floor or foundation
- A quiet fan continuously draws radon gas from beneath the home
- The gas is safely vented above the roofline
- Radon levels inside the home are significantly reduced
When properly installed, mitigation systems can reduce radon levels by up to 90% or more.
Does Every Ottawa Home Need Mitigation?
No. Only homes with elevated radon levels need mitigation.
Many Ottawa homes test below the guideline and require no action beyond periodic retesting. Others may benefit from simple improvements like sealing cracks or increasing ventilation—but these steps alone are usually not enough when radon levels are high.
The key is testing first, then acting based on data—not assumptions.
When Should You Test for Radon?
You should test your Ottawa home if:
- You’ve never tested before
- You’re buying or selling a home
- You’ve renovated the basement or foundation
- You’ve improved insulation or air sealing
- You’ve changed how the basement is used
- More than 5–10 years have passed since your last test
Testing is especially important during fall and winter, when radon levels tend to be higher due to closed windows and stack effect.
Is Radon Mitigation Worth the Cost?
For homes that exceed guidelines, yes—unequivocally.
Radon mitigation is typically a one-time investment with long-term benefits:
- Reduces lung cancer risk
- Improves indoor air quality
- Adds reassurance for current and future occupants
- Can increase resale confidence and value
Compared to the potential health consequences, mitigation is widely considered cost-effective.
Can You Do Radon Mitigation Yourself?
Basic steps like sealing cracks or improving airflow can help slightly, but effective radon mitigation should be performed by trained professionals.
Improper installation can:
- Fail to reduce radon adequately
- Create backdrafting issues with combustion appliances
- Increase energy costs unnecessarily
Professionals trained under Canadian radon standards understand Ottawa’s building styles, climate conditions, and best practices.
The Bottom Line: How to Know If You Need Radon Mitigation in Ottawa
You don’t need to guess. You don’t need to panic. And you don’t need mitigation unless testing proves it’s necessary.
Here’s the clear path forward:
- Test your home, ideally with a long-term radon test
- Review your results using Health Canada guidelines
- Mitigate only if levels are elevated
- Retest after mitigation to confirm effectiveness