Radon inspections: what happens and who does them

A radon inspection is a radon test of a home, usually done by a qualified radon tester during a sale. Very often that tester is a home inspector (EPA, Home Buyer’s and Seller’s Guide to Radon). It measures the radon level over at least 48 hours and reports whether the home is at or above EPA’s action level of 4 pCi/L. Nothing about radon can be seen in a walk-through: testing is the only way to know (EPA).

What happens during a radon inspection

1. Placement. The tester puts one or more devices in the lowest level of the home that could be used regularly, finished or not, in a space that could be a bedroom, family room, den, playroom or workshop. Devices don’t go in closets, stairways, hallways, crawlspaces, kitchens, bathrooms, laundry rooms or furnace rooms.
2. Closed-house conditions. Windows and outside doors stay closed except for normal entry and exit, starting 12 hours before a test shorter than four days.
3. The test. It runs for at least 48 hours. EPA accepts three short-term options in a sale: two passive devices side by side; two passive tests one after the other in the same spot; or a continuous radon monitor.
4. Interference checks. Because someone could open windows or move the device, testers may use monitors that log hourly readings, motion or tamper sensors, tamper seals on windows, and a non-interference agreement signed by the occupants.
5. The report. The home should be fixed if the average result is 4 pCi/L or more.

All from EPA’s Home Buyer’s and Seller’s Guide.

Who does radon inspections

Many states license, certify or register radon testers, and your state radon program can give you a list. States that receive EPA radon grants list only providers credentialed by the state or by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB) (EPA). In states that don’t regulate radon work, ask for a national credential. These come with a photo ID card showing the expiry date, which you can check with the issuing program (EPA, Home Buyer’s and Seller’s Guide).

Buyers often want a tester who has no stake in the sale (EPA, Citizen’s Guide).

If you’re buying

If the seller already tested, you can accept that result or ask for a new test. Before accepting it, find out (EPA):

• the result, and who did the test;
• where in the house it was done, especially if you plan to use a lower floor, such as the basement;
• whether the house, or its heating and cooling system, has changed since.

If there’s no test, have one done as soon as possible. EPA suggests the purchase contract say where the test goes, who does it, what kind of test, when, how buyer and seller share the results and costs, and when any radon fix will happen and who pays.

If the home has a radon system, ask for its test results and operating information. Sellers with a system should give buyers this (EPA, Consumer’s Guide to Radon Reduction). Check that the gauge shows it’s running.

If you’re selling

Test before you list, in the lowest level a buyer might use. If you already tested, share the results, but expect a buyer to ask for a new test if the last one is more than about two years old, if you’ve renovated since, or if it wasn’t done in the lowest usable level (EPA). If you find a problem, fixing it before you sell keeps it from complicating the sale (EPA, Citizen’s Guide).

Disclosure rules

Some states require sellers to disclose what they know about radon. In the six states where we publish full county data:

For other states, ask your state radon program or your real estate agent. If a test comes back high, see how radon mitigation systems work and what they cost.