Radon Testing in Winona and Winona County
You cannot smell radon, see it, or taste it. Your neighbor's result tells you nothing about your house. Testing is cheap. Fixing blind is not. This page covers how to get a number you can trust.
Three ways to test, and when each one fits
Short-term test
2 to 7 days on the lowest lived-in level. This is the right first step for most homeowners. If the result lands at 4.0 pCi/L or higher, confirm with a second test or move straight to a mitigation quote.
Long-term test
91 days to a year. Radon swings with the seasons. A Minnesota winter usually reads higher than summer because the house stays sealed and heated. A long-term test gives the truest picture of your yearly exposure.
Real estate test
Buying or selling starts the clock. A real estate test follows stricter placement and timing rules so the result holds up in the transaction. Minnesota law requires licensed measurement when it is done for hire.
Selling a house? Minnesota's disclosure law follows the radon
Since January 1, 2014, the Minnesota Radon Awareness Act has required sellers of residential property to disclose, in writing, any known radon results or past tests before a purchase agreement is signed. The seller also hands over the MDH publication on radon in real estate. A high result does not disappear. It travels with the house until someone fixes it.
For sellers around Winona this cuts two ways. An unmitigated high result can stall a closing or hand the buyer a bargaining chip. A mitigated home with an MDH-tagged system and a clean post-test reads as a selling point instead. Buyers' inspectors in Winona County order radon tests as a matter of routine, so learning your number before you list beats learning it during the option period.
High result on a deal deadline? Mitigation is usually a one-day job, and quotes come back fast. Get one here. The full guide for buyers and sellers, including who usually pays, is radon in a Winona home sale.
Testing right: the details that change the number
- Test the lowest level you use. A finished basement counts.
- Keep windows and doors closed for 12 hours before and during a short test. Normal coming and going is fine.
- Keep the kit away from drafts, sump pits, exterior walls, and humidity sources like bathrooms.
- Winter numbers run higher than summer numbers in Minnesota. A borderline summer result deserves a winter recheck.
- Retest every 2 years, after any foundation or HVAC work, and after a mitigation install to confirm it worked.
Want the local picture first? See radon levels in Winona and Winona County.