Radon in Wisconsin Homes
Radon is common in Wisconsin and the only way to know your home’s radon level is to test.
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil and rock. It can move through the ground and enter a home through openings in and around the foundation. Because radon has no color, odor, or taste, elevated levels can go unnoticed without testing.
Any home can have a radon problem, regardless of its age, foundation type, construction quality, or location.
Why Radon Matters
Long-term exposure to radon increases the risk of lung cancer. According to the U.S. Environmental Protection Agency, radon is the second-leading cause of lung cancer in the United States and the leading cause among people who do not smoke.
The risk is especially high for people who smoke or previously smoked, but prolonged radon exposure presents a health risk to everyone.
Radon does not typically cause immediate symptoms. The concern comes from breathing elevated levels over an extended period. Testing and mitigation can reduce that exposure.
Why Wisconsin Homes Should Be Tested
Elevated radon levels have been found throughout Wisconsin. Levels can vary significantly from one home to another—even between neighboring properties.
A neighbor’s test result cannot tell you what the radon level is in your home.
Wisconsin homes may have several possible radon entry routes, including:
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Cracks in concrete floors and foundation walls
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Open or improperly sealed sump basins
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Floor drains and plumbing penetrations
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Gaps around utility lines
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Construction joints
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Exposed soil in crawl spaces
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Openings around foundations and slabs
Basements and crawl spaces are common in northern Wisconsin, but homes built on slabs can also have elevated radon. New homes are not automatically protected, and a tightly constructed home can still test high.
Weather, soil conditions, heating systems, ventilation, and changes to the home can all affect indoor radon levels. That is why testing the individual property is essential.
Understanding Your Radon Test Result
Radon is measured in picocuries per liter of air, written as pCi/L.
The EPA recommends taking corrective action when a home’s radon level is 4.0 pCi/L or higher. Because no level of radon exposure is considered completely risk-free, the EPA also recommends considering mitigation when levels are between 2.0 and 4.0 pCi/L.
A single test provides information about the home during that testing period. Radon levels naturally fluctuate, so the appropriate next step may depend on:
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The radon level measured
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The type and duration of the test
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Where the test was placed
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Whether closed-building conditions were maintained
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Whether the result is part of a real-estate transaction
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Whether additional testing is recommended
If you are uncertain about a test result, a certified radon professional can help you determine the appropriate next step.
How Radon Enters a Home
Air pressure inside a home is often slightly lower than the pressure in the surrounding soil. This pressure difference can draw soil gases, including radon, into the building.
Radon may enter through cracks and openings that are visible, but it can also enter through gaps that are too small to easily identify. Sealing visible openings can be an important part of a mitigation project, but sealing alone is generally not a reliable method of controlling elevated radon.
An effective mitigation system is designed to collect radon-containing soil gas beneath the home and safely vent it outdoors before it enters the living space.
How Radon Mitigation Works
The most common residential mitigation method is active soil depressurization. A properly designed system uses one or more suction points and a continuously operating radon fan to create negative pressure beneath the foundation.
This helps redirect radon-containing soil gas through the system and discharge it safely above the home.
Depending on the property, a system may include:
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One or more suction points
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Interior or exterior vent piping
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A radon mitigation fan
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A system-performance indicator
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A sealed sump cover
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Sealing of accessible foundation openings
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A sealed crawl-space membrane
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Warning labels and system documentation
The appropriate design depends on the home’s foundation, soil conditions, drainage system, finished areas, additions, crawl spaces, and other construction details.
Every Home Requires Its Own Evaluation
Radon mitigation should not be approached as a one-size-fits-all installation.
Two homes with similar test results may require very different systems. Before finalizing a design, it may be necessary to evaluate:
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Foundation type and layout
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Slab and sub-slab conditions
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Sump and drain-tile configuration
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Crawl spaces and additions
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Finished basement areas
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Possible pipe and fan locations
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Electrical availability
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Airflow beneath the foundation
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Accessible areas requiring sealing
Diagnostic testing helps determine how air moves beneath the home and whether the proposed suction locations are likely to provide adequate coverage. This information allows the system to be designed around the property rather than relying on assumptions.
What Happens After Mitigation?
Every radon mitigation system should be followed by an independent radon test to verify its performance.
Post-mitigation testing should begin only after the system has operated for the required period and should be conducted according to the test manufacturer’s instructions and applicable testing protocols.
The system’s performance indicator should also be checked periodically. This device shows whether the fan is creating pressure within the system, but it does not measure the home’s radon level. Only a radon test can confirm the radon concentration inside the home.
Homeowners should also retest periodically and after significant changes to the property, such as:
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Foundation repairs
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Basement remodeling
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New additions
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Heating or ventilation changes
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Drainage or sump modifications
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Changes to the mitigation system
Can Radon Be Reduced?
Yes. Elevated radon levels can usually be reduced with a properly designed and installed mitigation system.
The goal is to reduce radon as much as reasonably achievable—not simply to install a fan and pipe. System performance depends on proper evaluation, appropriate equipment, thoughtful pipe and suction-point placement, professional installation, and post-mitigation testing.
Radon Mitigation for Northern Wisconsin Homes
Northern Radon Mitigation provides property-specific radon mitigation services throughout northern Wisconsin.
Our standard installations include diagnostic testing and are designed around the construction and conditions of the individual home. We focus on effective system performance, clean workmanship, and clear communication throughout the process.
To begin, complete our quote questionnaire with information about your home and radon test results. We may request photographs or a short video walkthrough before determining whether we can prepare a proposal remotely or whether an on-site assessment is appropriate.
Take the Next Step
If your home has tested at or above the EPA action level or you would like help understanding your results, we are ready to review your property.