2018 IRC
Effective February 21, 2021 under Ordinance #206-2020-21.
The quick read
One county. One code regime.
Appendix F
“Radon Control Methods” is explicitly included in the adopted appendix list.
0 local pros
No NRPP-listed provider is based in Hartsville or Trousdale County.
112 permits
Building permits reported for 2025, raising the stakes for consistent new-home enforcement.
Mandatory on paper.
Practice is not yet confirmed.
Appendix F is not a suggestion here. The adopting ordinance specifically includes it.
The appendix’s radon-control provisions are therefore part of the enforceable local residential code for new one- and two-family dwellings. The strongest unanswered question is operational: whether the codes office consistently requires the passive radon components on permits.
What the ordinance says
“Adding Appendix A-C, F, H, K-M, Q, T”The same ordinance excludes the 2018 IRC’s sprinkler section and replaces its energy-efficiency chapter with the 2009 version.
First reading: 16 yes, 3 no.
Second reading: 20 yes, 0 no; ordinance approved.
The 2018 IRC adoption became effective.
The risk signal is clear.
The county number is not.
Two independent indexes place Trousdale County in EPA Zone 1, the category for the highest predicted radon potential. But the state testing dashboard’s tiny county polygon could not be reliably selected after repeated attempts.
Publishable
Zone 1
Both city-data.com and RadonResources list Trousdale County in Zone 1.
Withheld
3.6?
State test figures that couldn't be confirmed on repeat checks aren't shown here. A missing figure doesn't mean radon is absent; test your home to know its level.
Dashboard caveat: its 2022–2023 pre- and post-mitigation charts show Mid-Cumberland Region aggregates, not Trousdale-only counts. Selecting a county does not re-filter those charts.
Ask. Verify. Test anyway.
Put radon in the contract
The Tennessee residential disclosure form advises buyers to include a radon inspection contingency. The seller’s disclosure is not a substitute for testing.
For a new build, ask for the Appendix F system
Request documentation of the passive radon-resistant features required by the adopted code. County enforcement practice has not been confirmed online.
Test after occupancy
Radon-resistant construction reduces risk; it does not prove a low indoor level. Testing remains the check that matters for the actual home.
Radon testing resources
Test your home
Free test kits from TDEC ↗
EPA kit & pro guide ↗
Search the NRPP directory ↗
Search the NRSB directory ↗
1-800-SOS-RADON
Buy a test kit by phone: 1-800-767-7236.
1-800-55RADON
Live help with radon questions: 1-800-557-2366.
1-800-644-6999
Fix-It Hotline for guidance on reducing radon.
Certified pros: NRPP 800-269-4174
NRSB 866-329-3474
Free American Lung Association Radon Basics course ↗
~21,000U.S. lung-cancer deaths linked to radon each year
#2 / #1Second-leading lung-cancer cause overall; first among never-smokers
1 in 15U.S. homes estimated to have elevated radon
~9×Increase in lung-cancer risk from smoking plus radon among smokers
Act at 4 pCi/L. EPA recommends fixing at or above 4 pCi/L and considering action between 2 and 4 pCi/L.
Keep testing. Retest at least every 2 years if you have a mitigation system, and after renovations or changes to how you use the lowest floor.
How do I find a certified radon professional in Trousdale County?
Tennessee doesn't license radon testers or mitigators, so national certification is the best way to check qualifications. The Tennessee Radon Program points residents to two directories: search them by ZIP code and widen the radius if nothing is listed nearby.
We don't recommend or rank companies. Before you hire, check the certification number in the directory yourself and ask for a follow-up test after any system is installed. Questions to ask a radon professional.
Read the record.
The underlying EPA zone map could not be cleanly read from the archived PDF, so the Zone 1 classification is presented at two-index confidence rather than primary-source confidence.