Janesville sits in southern Wisconsin's Rock County, classified EPA Zone 1 (highest predicted radon). Wisconsin DHS reporting identifies ZIP codes 53546, 53505, and 53114 as having 59-100% of tested homes returning elevated readings. The area sits on the eastern edge of the Driftless-influenced south-central Wisconsin carbonate belt, with uranium-bearing bedrock contributing to consistent high radon readings.
Geology: Janesville's cold winters drive sustained stack-effect-driven radon influx during closed-house conditions.
Permits: Wisconsin does not require state-level licensing for radon mitigation. City of Janesville / Rock County standard building permits may apply.
Neighborhoods we serve in Janesville: Old Fourth Ward, Courthouse Hill Historic District, Look West, Lustron Historic District, Downtown Janesville, Beloit Road, Highland-Riverside.
All Janesville radon work is performed by NRPP/NRSB-certified partner contractors routed through Wisconsin Radon Experts. Wisconsin does not require a state radon contractor license — national NRPP/NRSB credentialing is the consumer-protection standard.
Rock County averages pCi/L indoor radon — well above the EPA action level of 4 pCi/L. Here's how Janesville's radon profile compares to other Wisconsin cities we serve.
| Metric | Janesville, WI | Wisconsin State Average | US National Average |
|---|---|---|---|
| Average indoor radon | null pCi/L | 5.7 pCi/L | 1.3 pCi/L |
| EPA Radon Zone | Zone 1 | Zone 1 (26 of 70 counties, 37%) + Zone 2 (44, 63%) | Varies (Zones 1–3) |
| % homes elevated (>4 pCi/L) | null% | ~10% (1 in 10) | ~6% |
| Multiple of EPA action level | 0.0x | 1.4x | 0.3x |
| EPA action level | 4.0 pCi/L | 4.0 pCi/L | 4.0 pCi/L |
Active radon mitigation system installation for Iowa homes — sub-slab depressurization is the most common method, reducing indoor …
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Professional radon testing services for Iowa homes — short-term (2-7 day) and long-term (90+ day) testing options. Required for mo…
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Iowa's most common radon mitigation method — sub-slab depressurization (ASD) creates negative pressure beneath the basement slab, …
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Sub-membrane depressurization for Iowa homes with crawl spaces — includes vapor barrier installation, sealing, and active depressu…
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Radon mitigation integrated with existing sump pump systems — uses the existing sump pit as an active depressurization point with …
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Independent verification testing after radon mitigation system installation — confirms that the installed system has reduced indoo…
Learn more →Wisconsin Statute § 709.03 requires sellers to disclose any known radon information via the Real Estate Condition Report (Form WB-3). In practice, most Janesville real estate transactions now include a radon contingency in the purchase agreement — and given that % of Janesville homes test elevated, buyers are increasingly insisting on pre-closing mitigation when results exceed 4 pCi/L.
Our partner contractor network handles closing-timeline mitigations within typical 7–14 day windows, including post-mitigation verification testing to satisfy lender and inspector requirements.
Yes. Janesville's cold Wisconsin winters intensify radon entry through the stack effect — heated indoor air rising creates negative pressure in basements that pulls soil gas into the home at higher rates than warmer climates. Janesville winter radon readings are typically 30–50% higher than summer readings.
EPA recommends radon testing under closed-house conditions, which align naturally with Janesville winters. If your Janesville home tested low in summer, retest in winter for an accurate baseline before deciding on mitigation.
Recent radon mitigation projects across Iowa — every image is geo-tagged to a specific Iowa city and entity-described for transparency and provenance. All work performed by NRPP-certified, IDPH-registered partner contractors.
📍 Madison, Wisconsin 
📍 Milwaukee, Wisconsin 
📍 Wausau, Wisconsin 
📍 Waukesha, Wisconsin Reviews shown with structured detail per our coached-review program — partner contractor, service type, Iowa city, and pre/post radon reduction data are documented for transparency. Placeholders shown pre-launch; real Iowa homeowner reviews will populate this section after the first partner installs complete.
"[Placeholder pre-launch. After first partner installs, this slot will populate with a real coached review including specific pCi/L reduction numbers, the certified partner contractor's name, the Iowa city, and a 1-2 sentence customer experience description. Example format: 'Pre-mitigation reading was 12.1 pCi/L. Post-mitigation came back at 1.4 — 88% reduction. Our partner contractor was punctual, professional, and explained every step.']"
"[Placeholder for coached review from Cedar Rapids partner install. Will include named NRPP-certified partner contractor, real pCi/L reduction data, and customer experience detail. Replace after first 5 partner-completed projects.]"
"[Placeholder for coached review from Iowa City real estate transaction radon mitigation. Will highlight closing-timeline turnaround, partner contractor name, and pre/post radon test results. Replace after first transaction-driven install.]"
Milwaukee County · 10 pCi/L avg
Dane County · 3.1 pCi/L avg
Brown County · pCi/L avg
Kenosha County · pCi/L avg
Racine County · 8 pCi/L avg
Outagamie County · pCi/L avg
Waukesha County · 4.8 pCi/L avg
Eau Claire County · pCi/L avg
Same-day routing to a Rock County NRPP/NRSB-certified partner. Written quote within 48 hours of site assessment.
