Radon mitigation cost in Columbus: reading a quote line by line

You have a radon mitigation proposal on the kitchen table, and the only line anyone has talked about is the total. Ohio puts most of your protection in the other lines, and those same lines explain why one Columbus house lands near $1,200 while another lands near $2,400.

What an Ohio proposal has to say before any work

Mitigation in Ohio cannot start on a handshake. The Ohio Radon Mitigation Standards, an appendix to Ohio Administrative Code rule 3701-69-08, require a visual inspection first, recorded on a floor plan drawing that shows the foundation, drains, HVAC equipment, entry points, diagnostic results, pipe layout, and fan location. Then comes a signed proposal, and it has to list:

• Ohio license numbers for the mitigation specialist and the mitigation contractor
• The scope of work and an estimated completion date
• Chemical hazards that come with the work
• A statement that the job complies with the Ohio standards
• What you, the homeowner, will need to maintain
• The installation price plus an estimate of what the system costs to run each year
• Either a guarantee to bring the average under 4 pCi/L, with its conditions, or a statement that no guarantee is offered and why
• A conflict disclosure when the same licensee also tested or advised on the house

A proposal missing the yearly operating cost or either license number is incomplete under Ohio rules, however polished it looks. The Ohio mitigation proposal FAQ covers the signing step itself.

The base price comes from the foundation

Your foundation sets the band:

• Active sub-slab system in a basement or on a slab: $1,200-$2,400
• Crawl space system under a sealed membrane: $1,800-$3,500
• Putting a fan on a passive pipe a builder already ran: $700-$1,200
• Repair or fan work on an existing system: $200-$600

The pricing by foundation type resource walks through each band, and the Columbus cost FAQ has the short answer. Where a quote falls inside its band depends on six line items, and each one maps to a specific Ohio requirement.

The line items that move the number

Communication testing and suction points

When nobody knows what lies under the slab, Ohio requires a communication test first: suction is applied at one small hole and read at others to see how far it travels. Much of Franklin County sits on clay-rich glacial till, and a slab poured over tight fill can leave one end of a basement cut off from the other. If the field fades partway across, the answer is a second suction point, meaning another core, more pipe, and more labor. A proposal that prices two points should tell you what the test showed.

Interior chase or exterior run

The discharge rules pick the route more often than the homeowner does. The exhaust must end above the highest eave and as close to the ridge as possible, at least 10 feet off the ground and 12 inches above the roof surface. It also has to stay 10 feet or more from any window, door, or opening that is less than 2 feet below the exhaust, and from openings into a neighboring building. Rain caps are not allowed. The fan may go only in an attic, in a garage with no living space above it, or outdoors, never in a basement, crawlspace, or conditioned room.

An interior route climbs through a closet or chase to an attic fan and out the roof, so the money goes to carpentry. An exterior route mounts the fan outside and runs pipe up past the eave, so the money goes to pipe and wiring. On close-set lots in Clintonville or German Village, the 10-foot rule toward a neighbor's windows can rule out a whole side of the house.

Sealing scope

The joint where floor meets wall gets urethane caulk, with backer rod behind it anywhere the gap tops half an inch, and a channel drain along that edge has to keep draining. Cracks and utility penetrations are closed too, and any opening that cannot be closed must be disclosed to you in writing. EPA treats sealing as a partner to suction, not a fix by itself. A poured wall in a newer Powell subdivision needs little of this; an older stone foundation in Old North needs far more, and the price follows.

The sump cover

A pit with a working pump in it should not serve as the main suction point, yet it still has to be closed off. The Ohio standard calls for an airtight cover with a view port, strong enough to hold a 155 pound person, sealed with silicone so the pump stays serviceable, and labeled.

Wiring, monitor, and labels

An exterior fan must be hard-wired, with an outdoor disconnect in sight of the fan and no more than 4 feet from it. A cord and plug is allowed only up to 6 feet and never through a wall. Each active system gets a monitor that warns when the fan stops, plus a manometer marked at its start-up reading, and you receive that pressure figure in writing. RADON REDUCTION SYSTEM labels go on exposed pipe on every floor, on the outdoor fan and pipe, and at the breaker. A quote that is cheap because these items are absent is cheap because it does not comply.

The crawl space membrane tier

In a crawl space the membrane is the system, which is why crawls price higher. Ohio sets the minimum at 6 mil polyethylene or 3 mil cross-laminated sheet, heavier when the crawl holds storage or gets regular foot traffic, with seams lapped at least 12 inches and sealed, and edges fastened mechanically to walls and piers.

Two lines that protect you after you pay

The yearly operating cost estimate matters because the fan never rests. EPA guidance says it should never be turned off, so its electricity is a standing household expense, and Ohio makes the proposal name a figure instead of leaving you to discover it on an AEP Ohio bill.

The guarantee statement matters because meeting the standards is not the same as reaching a number; the Ohio standards say outright that compliance guarantees no specific radon level. A proposal can promise an average under 4 pCi/L or explain why it will not, but it cannot stay silent. A no-guarantee line on a stone foundation with a very high starting result can be honest. On a plain poured basement, it deserves a follow-up question.

Red flags before you sign

• A firm price over the phone, with no visual inspection and no floor plan drawing
• One license number or none, and no specialist named (see who needs an Ohio radon license)
• A fan in the basement or crawl space, or an exhaust ending at the rim joist or under an eave
• A pit with a live sump pump as the only suction point
• No monitor, no manometer, or no labels anywhere in the scope
• No operating cost figure, and no guarantee statement in either direction
• The same company ran your test, and the contract never mentions it

Any one of these is reason enough to ask for a revised proposal before you sign.

Check your proposal against the range

Enter your foundation type and home size in the cost calculator and hold the estimate up against your proposal. A price well above the range should be explained by the line items above; a price well below it often means some are missing. Call or text (380) 221-7233 and we will go through the proposal with you, one line at a time.