Choosing a Radon Mitigation Contractor

Rutherford County is in EPA Radon Zone 1, so plenty of Murfreesboro, Smyrna and La Vergne homeowners end up hiring a radon contractor after a home inspection or a TDEC test kit. The work is usually done in a day, but the choices made before that day decide how well the system works and how long it lasts. The EPA's Consumer's Guide to Radon Reduction has a section on selecting a contractor. Here's that guidance organized around the decisions you'll actually make.

Who is qualified?

The EPA recommends using a certified or qualified radon mitigation contractor trained to fix radon problems. It warns that without the right equipment and knowledge, a do-it-yourself fix can actually raise radon levels or create other hazards. Tennessee doesn't license radon mitigators (see our permits and licensing guide). For states like Tennessee, the EPA suggests asking whether the contractor holds a professional proficiency or certification credential and follows industry consensus standards. The two national credentials are:

• NRPP, the National Radon Proficiency Program
• NRSB, the National Radon Safety Board

The EPA notes that these programs usually issue a photo ID card with an expiration date. Ask for the number and look it up on the program's site. TDEC's Tennessee Radon Program is another place to ask for information about radon service providers, and the EPA also suggests checking with your county or state consumer protection office.

Before you get a price: questions to ask

The EPA checklist for evaluating contractors asks:

• Will they give you references or photos, and before-and-after test results from past jobs?
• Can they explain what the work involves, how long it takes and exactly how the system will work?
• Will they charge for diagnostic tests? Many give free estimates but charge for diagnostics. Diagnostics can be necessary for an unfamiliar house type or a difficult job.
• Will they inspect the house before giving an estimate?
• Will they review your radon results and whether the test was done properly?

Middle Tennessee has a lot of crawl space and slab homes, plus townhomes with shared walls. Each foundation calls for a different approach, so a contractor who prices the job without seeing it is guessing. See our crawl space guide and townhome guide for what's involved.

Comparing bids side by side

The EPA cautions against comparing on price alone. A cheaper system may cost more to run and maintain or look worse on the house. A more expensive design may suit your home better, and material quality affects lifespan. Lay the bids side by side and check whether each includes:

• Proof of certification or proficiency credentials
• Proof of liability insurance and bonding, and any locally required licenses
• Diagnostic testing before design and installation
• A warning device that alerts you if the system stops working
• A radon test after installation
• A guarantee to reduce radon to 4 pCi/L or below, and for how long

Also note which fan each company plans to use, because that drives your electric bill (see what a radon fan costs to run). Our cost guide covers typical installed prices.

What belongs in the contract

The EPA says to get a contract before any work starts and to confirm it matches the proposal. Its list of contract contents:

1. Total cost, including taxes and permit fees, the deposit and when final payment is due
2. Time needed to complete the work
3. An agreement to get necessary permits and follow building codes
4. A statement that the contractor carries liability insurance and is bonded and insured
5. Responsibility for damage during the job, and for cleanup
6. Details of any guarantee to reduce radon below a negotiated level
7. Warranty details for the fan and other hardware
8. Whether the warranties or guarantees transfer if you sell the home
9. What you're expected to do before work begins, such as clearing the work area

Permits in this area depend on your address. Inside Murfreesboro, the city's Building and Codes Department handles electrical permits. Smyrna has its own Building Safety Department, and much of the rest of the county falls under the state electrical inspection program. Have the contract say who pulls the permit and whether the fee is included.

Inspecting the finished job

The EPA lists basic installation requirements you can check:

• The system is clearly labeled.
• The exhaust vents above the roof surface and at least 10 feet above the ground. It is at least 10 feet from windows, doors and other openings, unless it ends at least 2 feet above them.
• The fan is not in or below a living area. The EPA says it should be in unconditioned space.
• An outdoor fan is rated for exterior use under local code.
• Electrical connections follow local electrical codes.
• A warning device is installed where you can easily see or hear it, and the contractor shows you that it works.
• You receive written operating and maintenance instructions and copies of the warranties.

The follow-up test

The EPA recommends testing within 30 days of installation, but no sooner than 24 hours after the fan starts. A 2- to 7-day test is recommended, with windows and doors closed for 12 hours beforehand and throughout, except for normal entry and exit. The contractor may test their own work, but the EPA recommends an independent measurement as well. That can be a separate tester or a kit you run yourself, which avoids any conflict of interest. Retest at least every two years after that. Our maintenance guide covers the manometer and fan life.

Warning signs

• No certification number, or reluctance to let you verify it
• A firm price without seeing the house or your test results
• No written guarantee, no warning device or no post-test in the bid
• A fan placed in a closet, basement or other living space
• Pressure to sign the same day

Frequently asked questions

Does Tennessee require radon contractors to be licensed?

No. Tennessee doesn't license radon mitigation contractors. Ask for NRPP or NRSB certification and verify it on the program's website.

What should a radon mitigation bid include?

The EPA checklist says to look for proof of credentials and insurance, diagnostic testing, a warning device, a post-installation test and a guarantee to reduce radon to 4 pCi/L or below.

Do I need a contract for a radon system?

The EPA recommends a written contract before work starts, covering total cost, timing, permits, insurance, damage and cleanup, guarantees, warranties and whether they transfer on sale.

When should the system be retested?

Within 30 days of installation, but no sooner than 24 hours after it starts, ideally with an independent test. Retest at least every two years after that.

Is a cheaper radon bid a bad sign?

Not necessarily. The EPA notes a less expensive system may cost more to operate or look worse, so compare what each bid includes rather than price alone.

Where this information comes from

• U.S. EPA, Consumer's Guide to Radon Reduction (2016 PDF)
• U.S. EPA, Find a Radon Test Kit or Measurement and Mitigation Professional
• National Radon Proficiency Program (NRPP)
• National Radon Safety Board (NRSB)
• Tennessee Department of Environment and Conservation: Tennessee Radon Program
• City of Murfreesboro, Building & Codes
• City of Murfreesboro, Residential Electrical Permit Application (2026)
• Town of Smyrna, Building Safety permits and electrical permit information
• Rutherford County Building Codes, Electrical Permit
• EPA Map of Radon Zones, county data (Rutherford County, TN: Zone 1)