Radon Testing and Mitigation in Cleveland, Ohio: What to Know Before You Remodel | CLE Remodeling Co.

If you're planning a basement finish, an addition, or a whole-house remodel on an older Greater Cleveland home, there's a question worth asking before the first wall comes down: has this house ever been tested for radon? It's not a dramatic word, but it's a real one Northeast Ohio's geology is exactly the kind the EPA and Ohio's own health department both treat as a real, ongoing risk rather than a rare one, and a renovation is often the first time anyone actually opens up the areas where radon collects. Get it wrong and you can spend money finishing a space that still needs work done to it later. Get it right up front and it becomes one line item in a bigger project instead of a surprise after the drywall is up.

This guide walks through what radon actually is, when it becomes relevant to a remodel, what a mitigation system costs, who's legally allowed to install one in Ohio, and what the disclosure rules mean if you're renovating ahead of a sale. CLE Remodeling Co. has worked on 1,000+ projects across Greater Cleveland over 20+ years, including a lot of basements in the area's older housing stock — this is the version of the radon conversation we'd actually have with a client.

1. What Radon Is, and Why It Matters for a Cleveland Remodel

Radon is a colorless, odorless gas produced by the natural breakdown of uranium in soil and rock. It seeps into homes through foundation cracks, sump pits, and gaps around pipes, and it tends to concentrate in the lowest occupied level of a house  which, in most Greater Cleveland remodels, means the basement. According to the U.S. Environmental Protection Agency, radon exposure causes an estimated 21,000 lung cancer deaths in the United States every year, making it the second-leading cause of lung cancer after smoking.

The EPA's action level is a radon concentration of 4 picocuries per liter (pCi/L) of air. At or above that level, the agency recommends fixing the home; between 2 and 4 pCi/L, it recommends considering a fix. Ohio's geology puts a meaningful share of the state, including Cuyahoga County, in the range where elevated indoor readings show up regularly enough that testing before a major renovation is a reasonable default, not an overreaction.

2. When a Remodel Should Include a Radon Test

You don't need to test before every project a kitchen refresh on the second floor isn't going to change your radon exposure. But a few kinds of work make testing worth doing first:

• Basement finishing. You're about to spend years of your life in a space that, if untested, might be the highest-radon room in the house. Test before you finish it, not after.
• Any project that opens the foundation or slab. Sump pump replacement, foundation repair, or new plumbing penetrations can change how soil gas moves into the house.
• Older homes changing hands or being renovated for the first time in decades. If nobody has a record of a prior test, treat the house as untested.
• Additions built on a new slab or crawl space. New construction touching the ground is a natural point to build in radon-resistant features rather than retrofit them later.

A short-term test kit runs about $10–$30 for a DIY version, or roughly $125–$400 for a professional test with lab processing, according to HomeGuide's 2026 cost data. That's a small number to spend before committing to a basement remodel that could otherwise need to be reopened.

3. What a Radon Mitigation System Actually Involves

If a test comes back at or above 4 pCi/L, the standard fix is an active soil depressurization system: a sealed pipe run from beneath the slab (or through a sump pit) up through the house and out above the roofline, with an inline fan that continuously pulls soil gas out and vents it outside before it can enter the living space. It's a mechanical system, not a one-time repair — it runs continuously, similar to a sump pump, and needs periodic monitoring.

For a basement remodel specifically, timing matters. Installing the pipe run before you close up walls and finish the ceiling is dramatically simpler and cheaper than routing it through finished space afterward. This is one of the reasons we bring up radon early in the planning conversation on basement projects, alongside the same egress and moisture questions covered in our guide to basement egress window requirements.

4. What Radon Mitigation Costs in 2026

Per HomeGuide's 2026 cost data, a radon mitigation system installed nationally averages $1,200 to $2,000 , with a national average around $1,600 and a full range of roughly $500 to $8,000 depending on foundation type and system complexity. Wall-based systems, sometimes used on older stone or block foundations common in Cleveland's pre-war housing stock, run $500–$3,000 depending on the approach. Add professional testing ($125–$400), a permit ($25–$150 depending on the municipality), and about $70–$80 a year in electricity to run the fan continuously.

That's a modest line item next to the rest of a renovation for comparison, our basement remodel cost guide and basement finishing cost breakdown put most Greater Cleveland projects well into five figures. A mitigation system is a fraction of that, and it's far cheaper to build in during the remodel than to retrofit into a finished space later.

5. Who's Legally Allowed to Install One in Ohio

Unlike some home systems, radon mitigation isn't a do-it-yourself-friendly trade in Ohio. Under Ohio Revised Code Chapter 3701-69, the Ohio Department of Health (ODH) licenses radon testers, radon mitigation specialists, and radon mitigation contractors separately, and each requires approved training and a passing exam score. Per ODH's own reporting to the state legislature, a Radon Mitigation Contractor license currently costs $800 on a biennial renewal cycle, and Ohio licensees install an average of roughly 10,000 radon mitigation systems statewide every year, on the back of about 50,000 tests.

Practically, that means the same rule applies here as with any specialty trade: verify a contractor's ODH license before hiring them for testing or mitigation work, the same way you'd confirm a general contractor's registration before a larger project see our breakdown of what Ohio law requires of a licensed Cleveland contractor. As a remodeling company, we coordinate mitigation work with licensed radon specialists as part of the broader project rather than performing that specific scope ourselves.

6. Radon and Selling Your Cleveland Home

If part of the reason you're renovating is to get a house ready for market, radon has a legal dimension worth knowing about. Under Ohio Revised Code Section 5302.30, anyone selling residential real property in Ohio must complete a property disclosure form that specifically covers hazardous materials and substances including radon gas, lead-based paint, asbestos, and urea-formaldehyde foam insulation along with any known material defects. If you've never tested, you can generally disclose that honestly; but if a prior test turned up an elevated reading, that's disclosable information a buyer's inspection will likely catch anyway.

Addressing radon as part of a pre-sale renovation the same way you'd handle the issues covered in our EPA lead paint renovation rules guide for pre-1978 homes tends to be less disruptive and less costly than dealing with it during a real estate transaction under a closing deadline. It's also a detail buyers increasingly ask about directly in a market where renovation ROI is scrutinized project by project.

7. Folding Radon Into Your Renovation Plan

The practical version of all this: if you're finishing a basement, adding onto an older Cleveland-area home, or opening up a foundation for any reason, get a radon test scheduled before design gets locked in. If the result comes back elevated, build the mitigation pipe run into the framing plan rather than treating it as a change order later. And if a contractor tells you mitigation "isn't a big deal, we can wing it," that's a sign to ask about their ODH license.

At CLE Remodeling Co., we walk Greater Cleveland homeowners through this as one part of a bigger project plan — permits, code, moisture control, and radon all get discussed up front, not discovered mid-project. If you're planning a remodel that will need permits anyway, it costs nothing to ask the radon question at the same time.

Frequently Asked Questions

Ready to talk through radon, permits, and everything else before you start a basement or whole-home renovation? Contact CLE Remodeling Co. for a free, transparent estimate at (216) 505-0352.