Radon Mitigation in Wisconsin

If a test came back at or above the EPA action level of 4.0 pCi/L, the next step is a mitigation system, and in Wisconsin that usually means active sub-slab depressurization. Whether you are racing a home-sale deadline or planning ahead after a winter test, Badger State Radon connects you with independent local radon mitigation contractors who do this work across the state. We are a free matching service, not a contractor, so the sections below explain the process plainly and route you to the professional who will actually design and install your system.

How a sub-slab depressurization system works

Radon is a naturally occurring radioactive gas that seeps up from the soil and collects indoors. An active sub-slab depressurization system reverses that pressure. A radon professional cores a hole through the basement or slab, runs a sealed pipe down into the gravel or soil beneath, and connects it to a continuously running inline fan. The fan pulls radon from under the foundation and vents it above the roofline, where it disperses harmlessly. Because the system keeps the area under the slab at lower pressure than the house, radon takes the pipe out instead of rising into your living space. The EPA Consumer's Guide to Radon Reduction describes this as the most common and dependable approach.

System types by foundation

The right design depends on how your home sits on the ground. A radon professional matches the system to the foundation:

• Poured basement or slab: a single sub-slab suction point is often enough to treat the whole footprint.
• Block or hollow-wall foundations: hollow block can carry radon through the walls, so the system may add wall depressurization.
• Crawl space: a sealed plastic membrane over the soil, with suction drawn from beneath it, is called sub-membrane depressurization. See crawl space and basement radon.
• Homes with drain tile or a sump: the system can draw from the drain-tile loop or a sealed sump lid.

Sealing visible cracks and the sump opening supports the system, but sealing alone is not a fix. The depressurization is what lowers the level, and a post-mitigation test proves it worked.

What radon mitigation costs in Wisconsin

Wisconsin DHS estimates a contractor-installed system typically costs $1,000 to $2,000. The number moves with your foundation type, the square footage the system has to cover, how many suction points are needed, the fan size, and how visibly or discreetly the pipe is routed. A straightforward single-suction basement job lands near the low end; a home with multiple foundations or a finished basement sits higher. After installation the only recurring cost is the fan running around the clock, which adds a few dollars a month to the electric bill. Our Wisconsin radon mitigation cost guide breaks the pricing down further, and publishing honest ranges is deliberate, because it helps you plan.

Testing before and after

Mitigation starts and ends with a test. If you have not tested yet, or your only number came from a real-estate test, radon testing explains the short-term, long-term, and continuous-monitor options. After the system is installed, the radon professional runs a follow-up test to confirm the level dropped below 4.0 pCi/L. The EPA recommends retesting every two years and after any major renovation, since changes to the home can change how it breathes.

Who you are matched with

Wisconsin does not license radon contractors, so the market is an open one. The independent professionals we connect you with work locally and can hold the voluntary national credentials from the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Badger State Radon does not perform the work, does not hold any radon certification, and does not vouch for credentials it cannot confirm. What we do is match you quickly with a local contractor and step back so you can compare the quote and the plan yourself. For the full statewide picture, see the Wisconsin radon guide.