Radon Mitigation, Installed in a Day, Verified in Writing
A radon system is refreshingly simple: a pipe, a fan, and physics. We arrange licensed installs across the North Shore that pull soil gas from under your foundation and vent it above the roof, then prove the fix with a follow-up test.
How sub-slab depressurization works
Radon enters because the air pressure under your slab pushes soil gas up through every opening it can find. A mitigation system reverses that pressure relationship. The installer cores a small hole through the basement slab, digs out a suction pit, and runs 3- to 4-inch PVC pipe from that pit up and out of the house, with an inline fan pulling continuously. Soil gas that used to seep into your basement now gets collected under the slab and discharged above the eave, where it dilutes to nothing. The fix addresses the cause, not the symptom, which is why a properly sized system holds its number year after year.
Houses vary, so systems do too. Homes with a sump pit or drain tile loop often get suction through the sump with a sealed lid, which uses the drainage layer already under the house as a collection network. Crawlspaces get a heavy sealed membrane over the exposed soil with suction underneath it. Older foundations sometimes need a second suction point or crack sealing to tighten the system. Part of a licensed install is diagnosing which of these your house needs instead of drilling and hoping.
What Illinois requires, and why that protects you
Radon mitigation has been a licensed trade in Illinois since 1998. A compliant install carries a tag right on the vent pipe with the installer's name, phone number, and license number, includes a system gauge you can check yourself, and comes with the state's reminder to re-test every two years. We only work with state-licensed mitigation professionals, and the license number on the tag is yours to verify. The paper trail matters when you sell, too: a tagged, tested system is an asset at the inspection table instead of a question mark.
Permits, handled
North Shore villages treat a mitigation fan and its venting as permitted mechanical work. Northbrook issues mechanical permits through its Development & Planning Services department; Glenview runs permits through its Development Center and, notably, requires the venting work to satisfy the Illinois Plumbing Code specifically, since the village stripped the model code's plumbing chapters in favor of the state's. Evanston's building code adoption includes radon-control amendments of its own. This is paperwork we deal with routinely — it's part of the job, not an extra.
What it costs
Most single-family installs land between $800 and $2,500, with typical jobs around $1,200 to $1,500. The honest cost drivers: foundation type (poured slab vs. crawlspace vs. combination), pipe routing (a hidden interior run costs more than a straight exterior one), and whether one suction point can depressurize the whole footprint. What doesn't change is the sequence: test, quote firm, install in a day, verify with a follow-up test. If you're mid-transaction and the clock is running, our real estate page covers how mitigation fits an inspection timeline.
High test result? It's a one-day fix.
Call (224) 362-4440Frequently asked questions
Will the system be loud or ugly?
Neither, if it's routed with any care. The fan is about as loud as a bathroom vent running behind a closed door, and on most North Shore homes the pipe runs through the garage or a closet chase into the attic, exiting above the eave where you barely see it. Exterior runs are painted to match the house. Route and appearance get agreed on before anything is drilled.
How much does a system cost?
Most installs run $800 to $2,500. A straightforward sub-slab system on a poured foundation with an easy pipe route sits at the low end; crawlspace membranes, multiple suction points, or a long interior route to keep the pipe hidden push toward the high end. The quote is firm before work starts.
How do I know it actually worked?
Two ways, permanently. Every system includes a u-tube manometer on the pipe, a simple gauge that shows at a glance the fan is pulling suction. And every install is followed by a closed-house verification test to confirm the indoor level actually dropped, almost always below 2.0 pCi/L. Illinois also requires a tag on the pipe with the installer's name and license number, plus a reminder to re-test every two years.
Does a mitigation system help with anything besides radon?
Often, yes. The same suction that pulls radon from under the slab pulls out soil moisture and musty soil smells, which is why many basements feel noticeably drier after an install. It's a side benefit, not the design goal, but homeowners mention it a lot.