We build sub-membrane depressurization systems into a fully sealed crawl space — drawing soil gas out from beneath the barrier and exhausting it above the roofline.
All of Wilson County carries the EPA's Radon Zone 1 designation — the highest of three risk levels. The limestone bedrock that underlies Mt. Juliet, including the karst terrain around Cedar Creek and the Old Hickory Lake basin, contains trace uranium that decays into radon gas. That gas migrates upward through fractured rock and soil and collects under any foundation in its path, whether the home overlooks the lake or sits in a brand-new section off Providence Parkway.
Most of Mt. Juliet's housing stock went up between the early 2000s and today, and the typical build is a vented crawl space finished with thin 6-mil builder plastic laid loose on the dirt — never sealed at the seams or foundation walls. Radon slips past that plastic easily, then rides air currents up through subfloor gaps, plumbing and HVAC penetrations, and open foundation vents into the rooms above. Stack effect in two-story homes, common in Providence-area neighborhoods, actively pulls that soil gas upward.
For crawl space homes, the EPA-recognized approach is sub-membrane depressurization. We cover the entire crawl space floor with a heavy-duty sealed vapor barrier, run it up the foundation walls, and lock down every seam and penetration. A suction point goes in beneath the membrane, tied to PVC piping and a quiet inline radon fan that runs around the clock. Instead of drifting into your house, soil gas is captured under the barrier and pushed out above the roofline where it dilutes harmlessly.
Your system comes with a sealed 20-mil reinforced vapor barrier serving as the radon membrane, fully sealed seams and penetrations, a correctly sized suction pit, a low-watt inline fan rated for continuous duty, exterior PVC routed and terminated above the roofline per EPA guidance, a manometer-style system monitor so you can confirm the fan is pulling, and post-install radon testing to verify readings have fallen below 4 pCi/L.
Mt. Juliet crawl spaces also fight humidity, especially in low-lying lots near Cedar Creek and the lake. The same sealed membrane that blocks radon doubles as a full moisture barrier, so mitigation pairs naturally with crawl space encapsulation. If your home is already encapsulated, we can retrofit a suction point and fan to the existing barrier rather than starting over.
Every quote depends on the square footage under the house, how many suction points it takes to hold negative pressure beneath the membrane, whether an encapsulation already exists, and where the vent stack can run on the exterior. We put it all in a free written estimate after walking your Mt. Juliet crawl space in person.
We inspect your Mt. Juliet crawl space, look over any radon test results you have, and map out the suction layout your foundation needs.
An itemized scope and price, including any sealing or encapsulation work required for the system to hold negative pressure.
Membrane, suction pit, PVC routing, fan, and exterior termination — installed cleanly and code-aware.
We retest to confirm radon has dropped below the EPA action level and leave you with a working system monitor.
Yes. Wilson County is designated EPA Radon Zone 1, the highest-risk category, and homes across Mt. Juliet — from Providence-area subdivisions to older properties near Old Hickory Lake — test above the 4 pCi/L action level. The limestone bedrock under Wilson County is the driver, so no neighborhood is automatically safe.
Newer construction is not protection. Radon comes from the geology beneath the foundation, and Mt. Juliet's 2000s–2020s subdivisions were built fast on the same uranium-bearing limestone as the rest of Middle Tennessee. Many were finished with thin, unsealed builder plastic in the crawl space, which does nothing to stop soil gas.
We seal a heavy-duty vapor barrier across the crawl space floor and up the foundation walls, place a suction point beneath it, and connect that point to a quiet inline radon fan through PVC piping. The fan runs continuously, drawing soil gas out from under the membrane and venting it above the roofline.
Inline radon fans are built for continuous, quiet operation. Mounted on an exterior wall and properly isolated, the fan is typically barely audible from inside a Mt. Juliet home.
The fan is low-wattage, so the added cost is modest even running 24/7. Because the sealed membrane also cuts crawl space humidity, many homes see reduced HVAC load that helps offset it.
Yes. A pre-install test establishes your baseline, and a post-install test after at least 24 hours of continuous fan operation verifies the system is holding levels below 4 pCi/L.
Schedule a free crawl space evaluation. We'll walk the space, review any test results you have, and give you a clear plan.
Get My Free InspectionTell us a little about your home and we'll be in touch soon to schedule a no-pressure visit.
