Radon Testing at Home

Radon is a radioactive gas that seeps into homes as uranium in the soil around the foundation decays. Long-term exposure to high levels of radon causes lung cancer. More about the risks of radon.

Fond du Lac County buildings are prone to radon exposure. More about radon in WI.

Testing is simple. Fixing the problem is fairly straightforward too.

  1. Pick up a radon test kit at the Fond du Lac County Health Department (160 S. Macy, Fond du Lac; 3rd Floor).
  2. Start with a short-term 4-7 day test kit ($10).
  3. If you have a high result on a short-term test, try a long term test kit for 90+ days ($23).
  4. Set the device in the lowest, livable level of your home. This might be the basement if it is finished. Or it might be the first floor of your home if you don’t have a basement or never use it.
  5. Make sure the device is positioned at least 12 inches from exterior walls and from the ceiling, 3 feet from any opening (door or window) in an exterior wall, and 4 inches from any other object.
  6. When the testing period is over, mail it in the enclosed packaging.
  7. You will receive your results by mail.

Interpreting Results: Radon is measured in Pico Curies per Liter (pCi/L). The EPA has set the health standard for radon at 4pCi/L.

  • If your result is 4pCi/L or less, you do not need to take any action. You have little or no radon in your home.
  • If your result is 4-8pCi/L, you may want to consider re-taking a short-term test, or trying a long-term test to verify the result. You may also decide to do nothing or to mitigate your home.
  • If your result is greater than 8pCi/L, you will want to consider mitigation.

Radon mitigation ($400-700) in an existing home is done by a process called “sub-slab depressurization.” The basement is tightly sealed, and a 4″ diameter pipe is extended from below the slab in the basement out the roof. This pipe becomes a vent for any gas below the foundation to be released above the house. Find a certified radon mitigation professional.

If radon levels are still high in your home after doing the above procedure called “passive mitigation,” a fan can be installed at the top of the pipe in the attic making it “active mitigation.”  The fan creates negative pressure and actively sucks radon from below your foundation to vent it out the roof. It is important to find a certified mitigation contractor to do this work to ensure that it is done correctly and doesn’t further endanger the health of your family.
If constructed properly, a radon mitigation system is barely noticeable from the inside (shown here in a basement) or outside (an extra pipe is visible on the roof line.)

Building a radon-resistant new home.

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