Does Ohio require a radon test before selling a house?

We have not found an Ohio rule requiring a radon test for a sale. Ohio's residential property disclosure form asks sellers to disclose known radon gas, and EPA recommends that buyers know the radon level of any home they consider buying.

How long does a radon test take during a home sale?

EPA's Home Buyer's and Seller's Guide says a short-term test should run at least 48 hours under closed-house conditions.

Is a seller's old radon test good enough?

EPA suggests checking who did it, where it was placed and whether the house has changed. A buyer may ask for a new test if it isn't recent (for example, within two years) or if they'll use a lower level than was tested.

Buying a Home in Summit or Cuyahoga County: Radon and Basement Checks

Last reviewed Oct 29, 2026 · Sources linked in the text

Basements are one of the best features of Northeast Ohio homes, and one of the places where surprises hide. If you're buying, a little homework on radon and water before closing can save you money and worry later. Here is what the public sources say, in plain language.

Why radon matters here

The U.S. EPA calls radon the second leading cause of lung cancer after smoking, and says testing is the only way to know a home's level (EPA). EPA's radon map places Summit County in Zone 1, its highest predicted potential, and Cuyahoga County in Zone 2. Our radon guide has the local details. A county zone doesn't tell you about a specific house, though. Neighboring homes can test very differently, so it's worth testing the one you're buying.

What EPA recommends for buyers

EPA's Home Buyer's and Seller's Guide to Radon recommends that you "know what the indoor radon level is in any home you consider buying." It suggests you:

Ask the seller for any radon test results, and for information about a radon-reduction system if the house has one.
Test if the home hasn't been tested.
Test the lowest level you could use regularly. A buyer may plan to use a basement the seller never did.

Before relying on a seller's earlier test, EPA suggests checking who did it, where in the house it was placed, and whether there have been structural or heating and cooling changes since. EPA also notes a buyer may ask for a new test if the last one isn't recent (for example, within two years), the home was renovated, or the buyer plans to live in a lower level than was tested (EPA).

How a test during a sale works

According to EPA's guide, a short-term radon test should run at least 48 hours. For tests of 2 to 4 days, "closed-house conditions" (windows closed, doors closed except for normal coming and going) should be kept for at least 12 hours before and during the test. Disturbing the device or the closed-house conditions can invalidate the result (EPA).

What number to watch for

EPA recommends fixing a home at 4 picocuries per liter (pCi/L) or higher, and suggests considering a fix between 2 and 4 pCi/L (EPA Citizen's Guide). A high result doesn't have to end a deal. Buyers and sellers often negotiate who pays for mitigation. Your real estate agent or attorney can tell you how that is usually handled.

Licensed testers in Ohio

The Ohio Department of Health licenses radon testers (RT), mitigation specialists (RS) and mitigation contractors (RC). Its "Hire a Professional" page links to a map for finding licensed professionals (ODH). If the same company tests and then fixes the home, Ohio rules require the written contract to say so (OAC 3701-69-05). You can browse local radon testing and radon mitigation companies on this site.

What Ohio's seller disclosure form covers

Ohio law requires a residential property disclosure form for many home sales. Under the Ohio Administrative Code, the form covers the source of water supply, the sewer system, the condition of the structure "including the roof, foundation, walls, and floors," hazardous materials "including lead-based paint, asbestos, urea-formaldehyde foam insulation, and radon gas," and material defects "within the actual knowledge of the transferor" (OAC 1301:5-6-10; ORC 5302.30).

Two things to keep in mind. The form reflects what the seller knows, not a test. And some sales are exempt. Read the form carefully, and ask follow-up questions about anything checked "yes" about water or the foundation.

Basement checks during showings and inspection

A home inspector will look at the basement, but it helps to know what to notice yourself. Things worth noticing (the first three are warning signs local contractors list; see our wet basement guide for sources):

Water stains, damp spots or a musty smell
White chalky residue (efflorescence) on block walls
Cracks, or walls that bow inward
Fresh paint or new paneling on only the lower part of the walls
A sump pump that runs often, or a dehumidifier working hard
Gutters and downspouts that empty right next to the house, or soil that slopes toward it

Good questions for the seller: Has the basement ever had water? What was done about it, and by whom? Is there a written waterproofing warranty, and does it transfer to a new owner? Has a sewer line ever backed up?

If an inspector flags water or a wall issue, you may want a specialist to look before your inspection period ends. A waterproofing or foundation repair contractor can explain the cause and give a written estimate. Our contractor checklist and cost guide can help you compare.

Need a quote before closing?

Timelines in a home sale are short. If you need a radon test, mitigation quote or basement estimate quickly, use the free form on this page. We'll share your request with up to 3 local contractors in Summit or Cuyahoga County.