What's included
- Sub-slab depressurization designed to reduce radon below 4.0 pCi/L
- System sized to your foundation from an on-site diagnostic
- Post-mitigation radon testing to measure the result
- Sealed PVC venting routed to code above the roofline
- Fan placement planned around your home’s appearance
- Transparent pricing ranges up front (final price varies by home)
Why Allen County homes need radon mitigation
Radon is a colorless, odorless radioactive gas produced as uranium in the soil breaks down. You cannot see it, smell it, or taste it — the only way to know your level is to test. The EPA sets the action level at 4.0 pCi/L (picocuries per liter), and recommends fixing any home at or above it.
Lima and the rest of Allen County are in EPA Radon Zone 1, the highest-risk tier, where the predicted average indoor level is at or above 4.0 pCi/L. Locally, homes commonly test in the 5.0–7.6 pCi/L range. The reason is geological: Allen County sits on glacial till over fractured limestone bedrock. That uranium-bearing till and the cracked carbonate beneath it let radon-laden soil gas migrate up and collect in basements and lower levels — which is why radon is so common in Lima-area basements.
The health stakes are real: radon is the second-leading cause of lung cancer in the United States after smoking, and the leading cause among people who have never smoked. The good news is that it is completely fixable. A radon mitigation system is a permanent solution that vents the gas safely above your roofline before it ever enters your living space.
How a radon mitigation system works (the stack effect)
Homes naturally pull air upward — warm air rises and escapes at the top, creating a slight vacuum at the lowest level that draws replacement air, and soil gas, in through the foundation. This is called the stack effect, and it is why simply sealing cracks is never enough on its own: the house keeps pulling, and radon finds every remaining gap.
A radon mitigation system reverses that pull at the source. We create a low-pressure zone under your foundation slab and use an inline fan to continuously draw soil gas out from beneath the home and vent it up a sealed pipe to above the roofline, where it dissipates harmlessly. Because the system captures the gas before it enters, it protects the whole house — not just one room.
Radon mitigation system types we install
Active sub-slab depressurization (ASD) is the workhorse of radon mitigation — roughly 90–99% of installations. We core a suction point through the basement or slab floor, connect sealed PVC piping, and run an inline fan that keeps the sub-slab area under constant negative pressure. Piping can be routed through an interior chase or up an exterior wall depending on your home.
Drain-tile depressurization taps an existing perimeter drain-tile loop as the suction network, which can be highly effective when the tile ties the whole footprint together. Sump-pit and hollow-block-wall suction pull from an existing sump pit (sealed with an airtight lid) or from the cores of a block foundation wall — useful where the slab is hard to reach.
Sub-membrane depressurization is the crawlspace solution: we lay a heavy sealed vapor barrier across the crawlspace floor and draw radon from beneath it. Passive systems (common in newer construction with a radon rough-in) can be activated by adding a fan. Air exchangers / HRV dilution is used only as a last resort where soil suction is not feasible. We choose the method after a diagnostic — not off a template.
The radon fan matters — and we size it to your home
The fan is the heart of the system, and one size does not fit all. A tight, low-permeability sub-slab needs a high-suction fan; an open gravel bed under the slab needs high airflow instead. Matching the fan to the soil and foundation is the difference between a system that passes at 1.5 pCi/L and one that limps along at 3.9.
We install and stock proven radon fans and select by your diagnostic results: RadonAway (e.g. the RP145 at roughly 135 CFM, and the higher-suction GP-series), Fantech (e.g. the FR-150, around 243 CFM at 1.6 inches of water column), AMG Maverick (around 220 CFM at 1.88 in. WC), and FESTA fans. Higher water-column-inches means more suction for tight slabs; higher CFM means more airflow for permeable ones. We size for the lowest reliable radon level at the quietest, most energy-efficient operating point.
Our install process, step by step
1. Free diagnostic — we run a soil-communication / pressure-field test (and, where useful, a smoke test) to locate the best suction point(s) and confirm how easily air moves under your slab. 2. System design — we set the number and location of suction points from that diagnostic, not a guess. 3. Suction point — we core a ~5–6 inch hole in the slab and remove roughly 15–20 gallons of soil or gravel to open a collection pit.
4. Piping — we run sealed PVC up through an interior chase or an exterior wall. 5. Fan — mounted in the attic or outside, never in occupied space, per code. 6. Vent termination — the pipe exits above the roofline (at least 12 inches above the eave and clear of windows), per code. 7. Sealing — we seal foundation cracks, the sump lid, and other entry points with urethane caulk so the system does not fight air leaks.
8. Monitoring — we install a U-tube manometer so you can see at a glance the system is running, and a system label with the install date. 9. Final analysis — we verify airflow and suction. 10. Verification — a post-mitigation radon test measures the finished system against the EPA action level of 4.0 pCi/L.
How much does radon mitigation cost in Lima?
Most Lima and Allen County single-family homes fall in the $800–$1,800 range for a complete system. Larger homes, crawlspaces, multiple suction points, block-wall systems, or difficult routing typically run $2,000–$3,500. A radon test runs about $125–$175, a fan replacement about $300–$500, and adding a dedicated electrical circuit for the fan about $150–$450 when needed.
Final price always varies by home — foundation type, square footage, sub-slab conditions, and how the piping has to be routed all move the number. A firm written quote is provided before any work starts. Be cautious of quotes far under this range; a cut-rate system that never gets a home below 4.0 pCi/L is not a bargain.
How the result is measured
The point of a radon system is a measurable result — an indoor level below the EPA action level of 4.0 pCi/L. Rather than assume the result, a post-mitigation radon test measures it. Proper design matters here: fan sizing, suction-point placement, and sealing all determine whether a system actually reaches a low, stable level.
Radon levels naturally fluctuate with weather and season, so a system is judged on a proper post-mitigation test rather than a single spot reading. That measurement is what shows where a specific home stands relative to the action level.
After installation: testing and maintenance
Installation is carried out on site and the work area is left clean when the job is finished. Because radon can only be confirmed by measurement, a post-installation radon test is the step that shows how the finished system is performing.
A radon system needs a fresh test after installation to confirm performance (usually within 30 days), and re-testing every couple of years and after any major foundation or HVAC work is recommended. The mitigation fan itself is a low-maintenance, continuously running unit; the manometer tells you at a glance that it is doing its job.
Why cut-rate radon systems fail
A radon system is only as good as its design, and the cheapest bid is often the most expensive mistake. Under-sizing the fan, guessing at suction-point placement instead of running a diagnostic, skimping on sealing, or terminating the vent incorrectly can all leave a home hovering right at the action level — technically "mitigated," but not actually safe. When that happens, you pay twice: once for the failed system and again to have it corrected.
The tell-tale shortcut is a contractor who tests their own work once, gets a single reading under 3.9 pCi/L, and calls it done. Levels fluctuate, so a one-time squeaker is not proof. A sound approach designs from a diagnostic, sizes the fan to the foundation, and confirms the outcome with a proper post-mitigation radon test.
Why choose a local Lima radon specialist
National lead-gen sites and out-of-town chains route Lima searches to crews who do not know Allen County’s ground and may be hours away when a system needs a follow-up visit. Radon is a local problem with a local cause — our glacial-till-over-limestone geology and the 5.0–7.6 pCi/L levels that come with it — and it is well suited to a contractor who works and tests in the area.
Being local also means working on your timeline, which matters most during a home sale. We know the West-Central Ohio housing stock, carry the fans and materials the job needs, and are down the road if a system ever needs service.
Local to Lima & Allen County
Radon work in Ohio is regulated by the Ohio Department of Health, which licenses radon mitigation contractors (RC#) and radon specialists (RS#), and mitigation professionals are generally NRPP- or NRSB-certified. When hiring any radon contractor, ask to see their current license, certification, and insurance [insurer on file] on the proposal — a legitimate contractor will always show them.
We serve Lima and all of Allen County — Elida, Delphos, Bluffton, Spencerville, Cridersville, Beaverdam, Harrod, and Lafayette — plus the surrounding hubs of Wapakoneta, Ottawa, Van Wert, Kenton, and Findlay. Request a quote through the form and we will follow up with next steps.