2026-01-18 · 5 min read
Radon Mitigation Cost in Tennessee (2026): What to Expect
Radon risk in Tennessee is concentrated in the eastern counties — particularly along the Ridge and Valley region near Knoxville. Here's what mitigation costs.
Tennessee Radon: An Eastern Problem
Tennessee's radon story is largely a geographic one. Eastern Tennessee — running from Chattanooga through Knoxville and up to the Tri-Cities (Johnson City, Kingsport, Bristol) — sits on the Ridge and Valley geological province. The limestone, shale, and uranium-bearing formations there produce consistent radon concentrations, with many areas placing in EPA Zone 1.
Middle and West Tennessee (Nashville, Memphis) have significantly lower average radon levels, though testing is always recommended regardless of location.
Tennessee Average Costs by Foundation Type
| Foundation Type | Typical Range | Notes |
| Basement | $900–$1,900 | More common in East TN |
| Slab-on-grade | $800–$1,700 | Dominant in Nashville area |
| Crawl space | $1,300–$2,500 | Very common across all of TN |
| Block/stone foundation | $1,400–$2,800 | Older East TN homes |
Regional Price Breakdown
Knoxville Metro (Knox, Blount, Anderson Counties)
The highest-radon metro in Tennessee. Good contractor density driven by consistent demand.
- Sub-slab depressurization: $900–$1,900
- Crawl space with vapor barrier: $1,400–$2,500
Chattanooga (Hamilton County)
Elevated risk in parts of the area. Competitive market with several established contractors.
- Sub-slab depressurization: $850–$1,800
Tri-Cities (Johnson City, Kingsport, Bristol)
Northeast Tennessee — elevated risk similar to Knoxville. Smaller market, slightly fewer contractors.
- Sub-slab depressurization: $950–$2,000
Nashville Metro (Davidson, Williamson, Rutherford Counties)
Lower average radon risk — Middle Tennessee's geology produces less radon. Still test, but urgency is lower.
- Sub-slab depressurization: $800–$1,700 (fewer specialist contractors)
Memphis (Shelby County)
Lowest radon risk in the state. Mississippi alluvial plain geology. Still worth testing, but rare to need mitigation.
Tennessee's Crawl Space Challenge
Tennessee has one of the highest rates of crawl space construction in the South. Crawl space mitigation in Tennessee typically involves:
- Sub-membrane depressurization: Suction pipe placed under a vapor barrier across the crawl space floor
- Vapor barrier installation: Heavy-duty poly barrier (6–20 mil) sealed to walls and piers
- Foundation vent sealing: Closing off existing vents that allow humid outside air in
A full crawl space job — barrier + sealing + radon fan — typically runs $1,800–$3,200 in Tennessee. Don't let a contractor skip the vapor barrier; it's essential for both radon and moisture control in Tennessee's humid climate.
Tennessee Resources
- TDEC Radon Program: tn.gov/environment/radon or 888-891-TDEC
- Verify NRPP: radonproficiency.org
- Verify NRSB: nrsb.org
Frequently Asked Questions
Where is radon worst in Tennessee?
Eastern Tennessee — particularly the Ridge and Valley region running through Knoxville, Morristown, and Kingsport — has the highest radon concentrations. The geology there includes limestone, shale, and uranium-bearing soils. Middle and West Tennessee have lower average levels.
How much does radon mitigation cost in Tennessee?
Tennessee homeowners typically pay $800–$2,000 for a sub-slab depressurization system. Knoxville and Chattanooga have competitive markets. Nashville's lower-risk geology means fewer contractors specialize in radon there, which can affect pricing.
Does Tennessee require radon testing?
No state law requires radon testing or mitigation. However, buyers in East Tennessee increasingly request radon testing due to regional awareness. The Tennessee Department of Environment and Conservation (TDEC) recommends testing all homes.
What certifications do Tennessee radon contractors need?
Tennessee doesn't license radon mitigators, so NRPP or NRSB national certification is the standard. Verify at radonproficiency.org or nrsb.org.
Find a Certified Mitigator Near You
Every contractor on RadonBase is NRPP or NRSB certified — mitigators only, no testers.
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