Norfolk & Haldimand
Radon testing and mitigation in Caledonia & Haldimand County, Ontario
Haldimand County follows the Grand River from Caledonia to Dunnville, with Hagersville, Cayuga and Jarvis in between. Here’s what’s known about radon in Caledonia, and how to find out about your home.
- Region
- Norfolk & Haldimand
- Population
- about 49,000 (Haldimand County)
- Public health
- Grand Erie Public Health
- Local factors
- 4 reasons to test
Is radon a problem in Caledonia?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Caledonia 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, cracking clay soils, rural drilled wells and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Radon in Caledonia
Haldimand County follows the Grand River from Caledonia to Dunnville, with Hagersville, Cayuga and Jarvis in between. Caledonia has grown quickly as a commuter town for Hamilton, while most of the county is farmland with homes on private wells.
The ground under Caledonia
Much of the county sits on the Haldimand Clay Plain, dense clay laid down in glacial lakes. Clay slows soil gas, but it shrinks and cracks in dry summers, and the gravel under slabs and around weeping tile gives gas a ready path to the foundation. Along the Grand, river deposits are sandier.
Caledonia’s homes
Caledonia’s new subdivisions bring large, tight homes, many with finished basements. Older homes in Cayuga, Dunnville and Hagersville and farmhouses across the county add stone foundations, sumps and wells to the mix.
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)
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
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)
Local results
Building a real radon picture for Caledonia
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.
Caledonia: collecting results. Already tested? Check your number and share it anonymously when you book.
Local factors
What can push radon up in Caledonia
Not a prediction for any single home, just the reasons a test is worth it here.
Clay plains
Dense clay slows soil gas, but it cracks in dry spells. Gas then follows the easiest route: the gravel backfill, weeping tile and utility trenches that lead straight to a basement.
Rural homes on drilled wells
A 2024 national study of over 42,000 homes found rural residents were exposed to about 30% more radon than urban residents, with most of the gap linked to drilled wells. Researchers suspect gas travels up the gap around the well casing.
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
Caledonia neighbourhoods and nearby communities
- Caledonia
- Hagersville
- Cayuga
- Dunnville
- Jarvis
- Selkirk
- York
- Townsend
Nearby: Radon in Hamilton · Radon in Brantford · Radon in Port Dover
How it works
From test to fix
- Book
Tell us about your Caledonia 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 Caledonia: FAQ
Is radon a problem in Caledonia?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Caledonia 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, cracking clay soils, rural drilled wells and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Does clay soil protect my Caledonia home from radon?
Not reliably. Clay slows gas through the ground, but cracks, trenches and the gravel layer under your slab create shortcuts. Clay-soil homes test above the guideline too, which is why Health Canada recommends testing every home.
Do new homes in Caledonia need radon testing?
Yes. Homes permitted under the 2024 Ontario Building Code include a rough-in, not an active system. A long-term test after occupancy tells you whether to add the fan. Earlier homes usually have no rough-in at all.
Do you offer radon testing and mitigation in Caledonia?
Yes. We test and mitigate homes throughout Caledonia & Haldimand County, including Caledonia, Hagersville, Cayuga, Dunnville, Jarvis and nearby. Call (226) 271-4667 or book online.
Radon is fixable. First, know your number.
Serving Caledonia, Hamilton, Brantford and Port Dover.