Niagara Region
Radon testing and mitigation in Grimsby, Ontario
Grimsby sits on the narrow strip between Lake Ontario and the Escarpment, and has been one of Niagara’s fastest-growing towns. Here’s what’s known about radon in Grimsby, and how to find out about your home.
- Region
- Niagara Region
- Population
- about 29,000
- Public health
- Niagara Region Public Health
- Local factors
- 4 reasons to test
Is radon a problem in Grimsby?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Grimsby 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, converted cottages and crawlspaces and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Radon in Grimsby
Grimsby sits on the narrow strip between Lake Ontario and the Escarpment, and has been one of Niagara’s fastest-growing towns. New townhomes and condos near the lake share the town with the painted Victorian cottages of Grimsby Beach and homes on the Escarpment brow.
The ground under Grimsby
Below the Escarpment, the town sits on the Iroquois Plain: lake sands, silts and clays over red shale. Above it, “Grimsby Mountain” sits on dolostone with thin soils. Forty Mile Creek and other streams have cut through both.
Grimsby’s homes
Grimsby Beach cottages and older homes downtown often sit on shallow or patched foundations. Newer homes and townhouses are tight and tall. Homes on the Escarpment brow are built close to rock. Any of them can test high.
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 Grimsby
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.
Grimsby: collecting results. Already tested? Check your number and share it anonymously when you book.
Local factors
What can push radon up in Grimsby
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.
Cottages and crawlspaces
Lakeshore cottages converted to year-round homes often sit on crawlspaces, piers or patched slabs. Once winterized and heated, they can start pulling in soil gas they never did as summer places.
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
Grimsby neighbourhoods and nearby communities
- Downtown Grimsby
- Grimsby Beach
- Grimsby on the Lake
- Grimsby Mountain
- Smithville (West Lincoln)
Nearby: Radon in Beamsville · Radon in Hamilton · Radon in St. Catharines
How it works
From test to fix
- Book
Tell us about your Grimsby 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 Grimsby: FAQ
Is radon a problem in Grimsby?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Grimsby 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, converted cottages and crawlspaces and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Can townhouses have high radon?
Yes. Any unit with floor or walls in contact with soil can. In attached homes, results can also differ unit to unit. Each owner should test their own lowest lived-in level.
How soon can you test in Grimsby?
We typically place long-term detectors within a week or two of booking, and we serve Grimsby, Winona and West Lincoln on the same routes.
Do you offer radon testing and mitigation in Grimsby?
Yes. We test and mitigate homes throughout Grimsby, including Downtown Grimsby, Grimsby Beach, Grimsby on the Lake, Grimsby Mountain, Smithville (West Lincoln). Call (226) 271-4667 or book online.
Radon is fixable. First, know your number.
Serving Grimsby, Beamsville, Hamilton and St. Catharines.