How to Choose a Radon Mitigation Contractor in Chattanooga: 7 Questions to Ask

Your test came back at 8.2 pCi/L. Now you have three bids on the kitchen table ranging from $1,100 to $2,400, all of them promising to fix it, and no obvious way to tell which one is worth the money. Radon mitigation is one of those trades where the finished work is mostly hidden — a pipe, a fan, a patched hole — so the only leverage you have is the questions you ask before anybody starts drilling.

Here are the seven that actually separate the bids.

1. Are you certified, and can I see the number?

Radon mitigation professionals hold certification through the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). These aren't decorative. Certification means the installer has been trained on diagnostic testing, system design, and the national mitigation standards, and holds continuing education to keep it. Ask for the certification number and verify it yourself — it takes two minutes online. A contractor who deflects on this question has told you everything you need to know.

2. Will you do a communication test first?

This is the single best question on the list, and it's the one most homeowners never ask. Before choosing where to put the suction point, a good installer drills a small test hole and measures how far a vacuum actually travels under your slab. Chattanooga sits on varied ground — some homes have clean gravel under the slab, others have compacted clay that barely moves air at all, and plenty of houses on the ridges have a mix.

A contractor who skips this and puts the pipe wherever it's easiest to route is guessing. Guessing is how you end up with a system that runs, looks professional, and drops your level from 8.2 to 6.0.

3. Where will the pipe run, and where does it discharge?

You want two answers here. Interior routing — up through a closet, the garage, or a chase to the roofline — is generally tidier, quieter, and less prone to freezing than a pipe strapped down the outside of the house. Exterior routing is cheaper and sometimes the only practical option; it isn't wrong, but you should know it's what you're buying.

Discharge matters more. The standard puts the exhaust above the roof eave and well away from windows, doors, and any operable opening, so the soil gas you just pulled out of the house doesn't get drawn back in. If a bid has the pipe terminating at ground level or under a deck, that bid is not compliant.

4. What fan are you installing, and is it sized to my house?

Fan selection is a real engineering choice, not a catalog default. Low-permeability soil needs a high-suction fan; loose gravel needs higher flow at lower pressure. Ask for the make and model, ask what it draws in watts, and ask what the warranty is — quality radon fans typically carry a five-year manufacturer warranty and run continuously for a decade or more.

Also ask where the fan goes. It belongs outside the conditioned space — attic, garage exterior, or outdoors — never in a basement or crawl space, where a cracked housing would push soil gas back into the house.

5. Is a manometer included, and will you show me how to read it?

That small U-shaped tube of colored liquid on the pipe is your only ongoing indicator that the system is working. Every compliant install includes one. Every good installer walks you over to it, shows you the normal reading, and tells you what a level line means (fan failure, call us). If nobody mentions it during the walkthrough, ask.

6. Is post-mitigation testing included in the price?

A system that isn't retested is a system nobody has proven works. Retesting should happen no sooner than 24 hours and no later than 30 days after installation. Some contractors include it; some charge separately; some leave it to you. Any of those is acceptable as long as it's clearly stated in the bid — what isn't acceptable is a contractor who treats the question as unusual.

7. What happens if the level is still high?

Ask this one directly and listen carefully. Some homes need a second suction point, a sub-membrane system in a crawl space, or sealing work at a sump pit or floor-wall joint. A confident installer will tell you upfront that a follow-up is included in the original price if the first configuration doesn't get you under 4.0 pCi/L. A guarantee in writing is the difference between a contractor and a salesman.

Comparing the bids

Once you've asked all seven, the price spread usually explains itself. The cheap bid skipped diagnostics and is routing outside with a generic fan. The expensive one may include a second suction point your house genuinely needs. Look at what each system will actually do, not just what it costs.

We're glad to answer every one of these on the phone before you ever schedule. Learn more about how our mitigation systems are designed, or start with a test if you don't have a current number. Call (423) 529-4385 for a free quote.