We’re proud to be the Granite State, but the same geology that gives us those beautiful ledges and stone walls has a downside most homeowners never think about. Granite contains trace uranium, and as it breaks down it releases radon, a colorless, odorless radioactive gas that seeps up out of the ground and collects in basements and lower floors.
This isn’t a fringe concern here. It’s a New Hampshire problem in particular.
The numbers are not small
Roughly 30% of tested homes in New Hampshire come back above the EPA’s action level of 4.0 pCi/L. The state’s average indoor radon level is estimated somewhere around 5.5 to 5.9 pCi/L, among the highest in the country. The White Mountains region and much of the state’s granite bedrock carry elevated probabilities.
Why it matters: radon is the leading cause of lung cancer among people who don’t smoke, according to the EPA. It’s a slow, invisible exposure, which is exactly why testing is the only way to know.
Testing is cheap and easy
You cannot see, smell, or taste radon, so you test for it. A short-term test kit costs very little, and the New Hampshire Radon Program offers test kits to residents. You place the kit in the lowest lived-in level of the home, leave it for the specified window, and mail it to a lab. If your result comes back above 4.0 pCi/L, it’s time to act. Levels between 2.0 and 4.0 are worth keeping an eye on.
Mitigation actually works
Here’s the reassuring part. Radon is very fixable. A properly installed mitigation system, typically a sub-slab depressurization setup that vents the gas from beneath the foundation up and out above the roofline, can cut levels dramatically, in many cases by up to 99%. This is specialized work and the system itself should be installed by a certified radon mitigation professional. But a lot of the surrounding work is standard home repair: sealing foundation cracks and the sump pit, tightening up the basement envelope, and making sure the space is buttoned up so the system can do its job. That’s work we do all the time.
The part sellers need to hear
If you’re planning to sell, assume the buyer will test for radon. In New Hampshire, it’s a routine part of the inspection process, and a high radon result can stall or reprice a deal at the worst possible moment. Testing before you list, and mitigating if needed, takes that surprise off the table. It’s the same logic behind getting ahead of everything a home inspector is likely to flag before the buyer’s inspector writes it up.
Where we fit
We’re not a radon mitigation contractor, and we’ll tell you plainly when you need one. What we do is help you get the house ready: sealing the foundation and sump, handling the basement prep, and coordinating the pieces so the specialist’s system goes in clean. If you’ve got a result you’re not sure about or a sale on the horizon, reach out and we’ll point you in the right direction.
Sources
- New Hampshire Bulletin and Concord Monitor reporting on radon risk in New Hampshire (percentage of homes above action level, state average levels), 2023.
- U.S. Environmental Protection Agency, radon action level and health guidance.
- New Hampshire Department of Health and Human Services, New Hampshire Radon Program.
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