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radon testing


If you are buying a home or selling your home, have it tested for radon.

  • For a new home, ask if radon resistant construction features were used and if the home has been tested.

  • Fix the home if the radon level is 4 picocuries (pCi/L) or higher.

  • Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced.

  • Take steps to prevent device interference when conducting a test.

The EPA estimates that radon causes thousands of cancer deaths in the U.S. each year.

*Radon is estimated to cause about 21,000 lung cancer deaths per year. The numbers of deaths from other causes are taken from the Centers of Disease Control and Prevention's 1999-2001 National Centers for Injury Prevention and Control Report and 2002 National Safety Council Reports.


Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water, and gets into the air you breathe. Radon typically moves up through the ground to the air above, and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.

Any home can have a radon problem, including new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home since that is where you spend most of your time.

Nearly one out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more). Elevated levels of radon gas have been found in homes in your state.

  • Who should test for radon? Testing is the only way to find out your home's radon levels. The Surgeon general recommends testing all homes below the third floor for radon.

  • Can you fix a radon problem? After testing, if you find the home to have a high radon level, a Radon Remediation system can be installed to lower the radon levels in the home.

  • If you are selling a Home...

The EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point.

radon tester
House for Home Inspection


The EPA recommends that you know what the indoor radon level is in any home you are considering buying. Ask the seller for their radon test results. If the home has a radon-reduction system, ask the seller for information they have about the system.

If the home has not yet been tested, you should have the house tested.

If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.

These radon testing guidelines have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference. These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estate situations.


Have a test taken as soon as possible. If you can, test your home before putting it on the market. You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations.

The radon test result is important information about your home's radon level. Some states require radon measurement testers to follow a specific testing protocol. If you do the test yourself, you should carefully follow the testing protocol for your area or the EPA's Radon Testing Checklist. If you hire a contractor to test your residence, protect yourself by hiring an InterNachi qualified Certified Master Home Inspector.

The inspector will notify you that the test is going to be performed and make arrangements for placement and retrieval of the unit. For passive testing a Charcoal Canister, alpha-track detector, charcoal liquid scintillation, or an electretion chamber detector is placed in the lowest level of the home suitable for occupancy. This means the lowest level that you are going to use as living space which is finished or does not require renovations prior to use. The inspector will retrieve the unit in 48 hours to take to a local laboratory for testing. The inspector gives lab personnel your email address so that results can be sent directly to you. If this is not convenient for you, you and the inspector will discuss other arrangements. The inspector also receives a copy of the laboratory results of the radon test. If there are any concerns, the inspector will contact you and set up a second test to verify the first findings. If, in fact, the second test verifies the level of concern the inspector will contact you with remediation recommendations.

House for Home Inspection
Radon Inspection


In a new home, the cost to install passive radon-resistant features during construction is usually between $350 to $500. In some areas, the cost may be as low as $100. A qualified mitigator will charge about $300 to add a vent fan to a passive system, making it an active system and further reducing radon levels. In an existing home, it usually costs between $800 to $2,500 to install a radon mitigation system.

The EPA publishes, "Home Buyer's and Seller's Guide to Radon". Ask your Certified Master Inspector for a copy for you to read and keep.

ADVANCED PROPERTY INSPECTION, INC. 406-855-4349 is available to answer any questions you may have on Radon, Radon Testing, or Radon Remediation.

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