Confirmed
Clarksville: radon appendix excluded
The city adopted the 2018 IRC with Appendix G only, “excluding all other appendices.” Appendix F—the radon control appendix—does not apply.1
01
The county in three calls
One code finding is definitive, one is still open, and the public-record search found no local radon rule beyond state norms.
Open
County appendix list not verified
Unincorporated Montgomery County uses the 2018 IRC, but Resolution 20-10-6’s appendix list was not retrievable. Treat radon provisions as unresolved, not absent.24
Not found
No extra local radon mandate located
Research found no Clarksville or Montgomery County rule requiring radon tests in public buildings, schools, or real-estate transactions. “Not found” is not proof none exists.
02
Two jurisdictions, one critical difference in certainty
Both governments enforce the 2018 IRC from January 1, 2021. Clarksville’s appendix treatment is confirmed from current codified text; the county’s radon requirement was confirmed by phone on October 16, 2026.
Confirmed
City of Clarksville
- Code
- 2018 IRC
- Authority
- Ordinance No. 40-2020-21
- Adopted
- December 3, 2020
- Effective
- January 1, 2021
- Appendices
- Appendix G only; all others excluded
- Radon result
- Appendix F not adopted; radon-resistant new construction is optional
The controlling phrase is “including appendix G thereto, but excluding all other appendices thereto.”1
Verified by phone
Unincorporated Montgomery County
- Code
- 2018 IRC
- Authority
- Resolution 20-10-6
- Passed
- October 12, 2020
- Effective
- January 1, 2021
- Appendices
- Not verified from available web records
- Radon result
- Radon-resistant new construction is not mandatory — no radon testing is required (Montgomery County Building & Codes, by phone, Oct. 16, 2026)16
The 2011 predecessor adopted only Appendices G, H, and J—excluding radon Appendix F. That precedent is evidence, not proof of the 2020 list.5
03
Average4.6pCi/L
Median1.6pCi/L
Maximum9.4pCi/L
!
Do not publish a Montgomery County test count or “percent above 4.” Selecting Montgomery County narrows the dashboard’s band charts to the Mid-Cumberland Region, not the county. Those pre- and post-mitigation totals are regional aggregates. The county tooltip itself does not show sample size.3
How do I find a certified radon professional in Montgomery 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.
04
New does not mean radon-ready
Clarksville’s construction pace and Fort Campbell’s recurring PCS turnover make a simple buyer message especially important: test the house, even when it is brand-new.13
No. 23Clarksville’s national rank in SmartAsset’s 2026 boomtown report, the highest Tennessee placement cited.6
18%Housing-unit growth over five years in the same boomtown analysis.6
15,000+New housing units the city’s assessment says are needed by 2029.7
The county’s growth story and its radon-code story point in opposite directions.
- 1Test every home, including new construction.
A new-home warranty or code inspection does not substitute for a radon measurement.
- 2Put radon in the inspection contingency.
Do not rely on a seller’s “Unknown” disclosure response or on VA loan requirements to trigger testing.
- 3Use a credentialed measurement professional.
Check current NRPP or NRSB directory credentials and ask who performs mitigation if the result is elevated.
05
Radon testing resources
Straightforward ways to test, get live guidance, find qualified help, and understand what to do with a result.
Test your home
- Free test kit from TDEC, Tennessee’s radon program
- Buy a kit by phone: 1-800-SOS-RADON (1-800-767-7236)
- Live help with your questions: 1-800-55RADON (1-800-557-2366)
- Find a certified pro: NRPP 800-269-4174 · NRSB 866-329-3474
If your result comes back high
- 1-800-644-6999 — the Fix-It Hotline, for general guidance on lowering radon in your home
06
Primary trail and research sources
Direct records are separated from market and context sources. “Live verified” means the value or language was checked on the live source on October 15, 2026.
1
Clarksville Code of Ordinances, Sec. 4-801Municode · live verified · current version dated Aug. 6, 2026
Open source ↗2
Montgomery County Building & CodesCounty page confirming 2018 code adoption and Jan. 1, 2021 effective date
Open source ↗3
Tennessee Radon Testing dashboardCounty tooltip and health-region chart behavior · live verified
Open source ↗5
Montgomery County Commission, Sept. 12, 2011 agendaPrior code adoption listing Appendices G, H, and J
Open PDF ↗8
NRPP professional directoryClarksville ZIP 37040 search · live verified; count caveat applies
Open directory ↗10
Clarksville Building Official adopted-codes noticeRevised Jan. 15, 2021; corroborates 2018 IRC with Appendix G
Open PDF ↗11
EPA Zone 2 corroborationCity-Data Tennessee radon-zone list and RadonResources Tennessee profile · indexed in research; no valid public URL was carried forward
12
Tennessee transaction frameworkT.C.A. §66-5-202 and Tennessee Realtors Form F16 disclosure language; VA-loan testing standard · indexed in research; no valid public URL was carried forward
14
U.S. EPA and CDC radon hotlinesTest-kit ordering, live radon questions, Fix-It guidance, and certification-directory contacts
15
American Lung Association: RadonHealth statistics, recommended testing cadence, and free Radon Basics course
Open source ↗16
Montgomery County Building & Codes — personal communicationPhone call, October 16, 2026 · Asked whether radon testing is required in unincorporated Montgomery County; the respondent stated that no radon testing is required
Research standard: specific values are published only when carried by the source report. The Tennessee dashboard snapshot covers 2022–2023 and is not live-updating here. No county-level test count or band percentage is shown because the dashboard’s band charts aggregate the Mid-Cumberland Region. The “no local rule found” conclusion reflects the records searched, not a guarantee that no uncatalogued policy exists.
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