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How radon mitigation works, and how to find a licensed Ohio contractor

Most radon systems use a pipe and fan to pull radon from under the house and vent it outside (EPA). In Ohio, a business that does radon mitigation must hold an ODH radon mitigation contractor license (Ohio Adm. Code 3701-69-02).

General information only. This page summarizes public guidance from EPA and the Ohio Department of Health. It is not professional radon or medical advice. For questions about your home, contact ODH radon education staff (614-728-0272, [email protected]) or an Ohio-licensed radon professional (ODH).

How a typical system works

EPA calls this soil suction. In basement and slab-on-grade homes, the most common and usually most reliable method is active subslab suction (also called subslab depressurization): one or more pipes go through the slab into the gravel or soil beneath, and a radon vent fan pulls the radon out and vents it outdoors. Often a single suction point is enough (EPA Consumer's Guide to Radon Reduction). Sealing foundation cracks and openings makes the system more effective (EPA Citizen's Guide). Crawlspace homes have their own methods, and the right system depends on how your home is built (EPA).

What EPA says a proper install includes

• The system is clearly labeled.
• Exhaust vents above the roof surface, 10 feet or more above the ground, and at least 10 feet from windows, doors or other openings (unless it vents at least 2 feet above them).
• The fan is not in or below living space.
• Electrical work meets local code.
• A warning device (often a manometer, a liquid gauge) that shows if an active system stops working, placed where you'll see or hear it.

Source: EPA Consumer's Guide to Radon Reduction, which also tells you to confirm with your contractor that ASTM E2121 is met and to ask for written operating and maintenance instructions and warranties.

After it's installed

• Test within 30 days of installation, but no sooner than 24 hours after the system starts running. EPA recommends a 2 to 7 day test with windows and doors closed, and an independent test (or your own) in addition to any test by the installer (EPA).
• The fan must run continuously. EPA says fans may last five years or more, and they add slightly to your electric bill (EPA).
• Retest every two years (EPA; ODH).

Cost

EPA says most homes can be fixed for about the same cost as other common home repairs, but costs vary with how the home is built and how high the level is. Get one or more estimates from qualified mitigators (EPA Citizen's Guide). We don't publish price figures we can't source.

Finding a licensed Ohio contractor

1. Use the ODH lookup. ODH's "Hire a Professional" page points to its Radon Licensure map for licensed radon testers and mitigation contractors (ODH Hire a Professional; the map itself is on DataOhio).
2. Or ask ODH. The state keeps a list of all licensed radon testers, mitigation specialists and mitigation contractors and must provide a copy on request (Ohio Rev. Code 3723.11). Education staff: 614-728-0272, [email protected]. Licensing staff: 614-752-4425, [email protected] (ODH).
3. Check the license type. The business needs a mitigation contractor license, and on-site supervision of the work needs a licensed mitigation specialist (Ohio Adm. Code 3701-69-02). Ask for the license numbers and confirm them with ODH.
4. Shop it like any repair. EPA suggests getting references and more than one estimate (EPA).

We don't list or recommend specific contractors. Licenses change, so check with ODH directly.

Last updated: 2026-10-22