Niagara Region
Radon testing and mitigation in Thorold, Ontario
Thorold sits on top of the Escarpment along the Welland Canal, with a historic downtown, new subdivisions like Rolling Meadows, and a large student rental market tied to Brock University next door. Here’s what’s known about radon in Thorold, and how to find out about your home.
- Region
- Niagara Region
- Population
- about 24,000
- Public health
- Niagara Region Public Health
- Local factors
- 4 reasons to test
Is radon a problem in Thorold?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Thorold home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, lived-in basements and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Radon in Thorold
Thorold sits on top of the Escarpment along the Welland Canal, with a historic downtown, new subdivisions like Rolling Meadows, and a large student rental market tied to Brock University next door.
The ground under Thorold
Most of the city sits on dolostone cap rock of the Niagara Escarpment, with relatively thin glacial soils above it. Joints and fractures in the rock can carry soil gas. South toward Port Robinson, the land drops onto clay plain.
Thorold’s homes
Older homes downtown, rentals with basement bedrooms, and new homes in Rolling Meadows cover most of the stock. New homes permitted under the 2024 Code have a rough-in, but it’s passive until activated.
What the data says
Ontario homes at or above Health Canada’s 200 Bq/m³ guideline in the 2024 Cross-Canada Survey, more than double the share found a decade earlier.Source: Cross-Canada Survey of Radon Exposure in the Residential Buildings of Urban and Rural Communities (2024)
Roughly how many homes per health region the first national survey (2009–2011) could test. Too few to clear any neighbourhood, which is why public maps can’t tell you about your house.Source: Health Canada — Cross-Canada Survey of Radon Concentrations in Homes, Final Report (2012)
Higher average radon exposure for rural residents than urban residents in a 2024 national study of 42,051 homes, mostly linked to drilled wells.Source: Goodarzi et al., Scientific Reports (2024) — rural communities and drilled-well annuli
Local results
Building a real radon picture for Thorold
Public radon data for Southern Ontario towns is thin. The national surveys tested only a handful of homes per area. So we’re building our own: anonymized long-term results from homes we test, published by area once there are at least 30, so no single home can be identified and small samples can’t mislead.
Thorold: collecting results. Already tested? Check your number and share it anonymously when you book.
Local factors
What can push radon up in Thorold
Not a prediction for any single home, just the reasons a test is worth it here.
Shallow or fractured bedrock
Where rock sits close to the surface, as on the Niagara Escarpment or the limestone plains near Lake Erie, joints and fractures can act as pipelines that carry soil gas toward foundations.
Lived-in basements
Radon is usually highest on the lowest floor. Basement bedrooms, home offices and rental suites mean people spend hours a day where exposure is greatest.
New, airtight construction
Canadian research shows newer homes have tended to test higher than older ones. Bigger, taller and tighter homes create a stronger stack effect that draws soil gas in through the slab.
Century homes
Fieldstone, rubble and early concrete foundations, earth-floor cellars and open sumps give radon many ways in. Older doesn’t mean safer: these homes still need a test.
Where we work
Thorold neighbourhoods and nearby communities
- Downtown Thorold
- Rolling Meadows
- Thorold South
- Port Robinson
- Allanburg
Nearby: Radon in St. Catharines · Radon in Niagara Falls · Radon in Welland · Radon in Fonthill
How it works
From test to fix
- Book
Tell us about your Thorold home. We reply within one business day.
- Test for 91+ days
A certified technician places long-term detectors on your lowest lived-in floor. You get an early reading at 2 weeks.
- Get your result
Lab-verified average, explained against Health Canada’s guideline.
- Fix it if it’s high
A sub-slab system designed for your foundation, at a fixed price, with results guaranteed.
Questions
Radon in Thorold: FAQ
Is radon a problem in Thorold?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Thorold home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, lived-in basements and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Do landlords in Thorold have to test for radon?
Ontario doesn’t currently require landlords to test. Testing basement units is still a sensible step to protect tenants, and Health Canada recommends testing every home.
How much does radon mitigation cost in Thorold?
Most single-family systems in Ontario cost in the low-to-mid thousands of dollars, depending on the foundation, pipe route and number of suction points. We give a fixed quote after a site visit.
Do you offer radon testing and mitigation in Thorold?
Yes. We test and mitigate homes throughout Thorold, including Downtown Thorold, Rolling Meadows, Thorold South, Port Robinson, Allanburg. Call (226) 271-4667 or book online.
Radon is fixable. First, know your number.
Serving Thorold, St. Catharines, Niagara Falls, Welland and Fonthill.