What Radon Mitigation Costs in Knoxville (2026 Price Guide)

Most Knox County homes land between $900 and $2,500 installed. A straightforward basement system with an interior chase and an attic fan sits at the low end. A crawlspace needing a full sealed membrane, or a house where the pipe has to run outside, sits at the top. Anything quoted under about $700 deserves a hard look at what is being left out.

What actually drives the price

Foundation type. This is the biggest single factor. A poured slab or basement floor takes one core-drilled suction point. A crawlspace needs heavy sealed membrane across the entire floor, which is materials plus a day of labor in an awkward space, and it costs more.

Pipe routing. Where the pipe goes is both the cost driver and the thing homeowners care about most. An interior route through a closet or mechanical chase to an attic fan is cheapest and least visible. An exterior route, sometimes the only option in a finished basement, means more pipe, more sealing and more labor.

Number of suction points. Most homes need one. Large footprints, additions with separate slabs, or homes where a communication test shows poor sub-slab connectivity need two or more, and each one adds cost.

Sealing work. Slab cracks, an open sump pit, exposed soil in part of a crawlspace and gaps around utility penetrations all have to be closed for the system to hold suction. Minor sealing is normally in the quote. An unlined crawlspace or a badly cracked slab is a bigger job.

Foundation depth and access. Knox County has plenty of hillside houses with walkout basements and split levels. Awkward access costs labor.

What should be included in any quote you accept

• A pre-installation diagnostic, not just a walk-around
• All materials, the fan, the manometer and the labor
• Sealing of accessible cracks, the sump lid and utility penetrations
• Electrical connection to code for the fan
• A post-installation verification test, in writing, after the system has run
• A written guarantee of the result, not a promise of best effort
• Any permit required by the jurisdiction

Ongoing cost

The fan runs continuously and uses roughly the electricity of a light bulb, call it $3 to $8 a month depending on fan size and your rate. Radon fans typically last eight to twelve years and cost a few hundred dollars to replace. There are no filters and no consumables. Re-test every two years and after any major foundation or HVAC work.

Is it worth it

At a $1,400 average, mitigation is one of the cheapest permanent health interventions available for a house, and in a transaction it is small enough that it routinely gets absorbed as a credit. In Knox County, an EPA Zone 1 county, it is also one of the more likely repairs to come up. Test first. If your number is low, you have spent $150 and you are done.

Call (865) 563-8112 for a fixed written quote.