Radon is invisible, odorless, and common enough that every homebuyer, renovator, or concerned homeowner eventually runs into it. I have spent years installing radon mitigation systems and supervising testing across varied houses, from century-old brick homes in St. Louis neighborhoods to modern slab-on-grade builds in the suburbs. This article collects the questions homeowners ask most often, and it answers them with practical details you can act on today.
Why radon matters Radon is a radioactive gas produced when uranium in soil decays. It seeps through cracks, gaps around pipes, sump pits, and porous concrete into basements and living spaces. Long-term exposure to elevated radon increases lung cancer risk; the EPA and most health organizations view radon as a serious indoor air contaminant when levels exceed 4 picocuries per liter, or pCi/L. In practice, I treat any sustained result above 2 pCi/L as an issue worth addressing, because mitigation is straightforward and the health stakes are real.
Top questions from homeowners
- How do I know if my home needs a radon mitigation system? What does a radon mitigation contractor do, and what should I expect during installation? How much does a radon system cost, and what affects price? How long does a mitigation system take to install, and how disruptive is it? Will mitigation lower indoor air quality or cause other problems?
I will take each question in turn, mixing technical detail with trade experience so you understand both what the numbers mean and what the installers will do on site.
How homeowners discover radon Most homeowners find out through testing. Short-term tests run two to seven days and give a snapshot; long-term tests span 90 days to a year and average out seasonal variations. I recommend starting with a short-term test if you want a quick check, then following up with a long-term test if results approach action levels. Real-world example: a buyer in University City ran a short test showing 5.6 pCi/L. We installed mitigation, then performed a 90-day follow-up; the average dropped to 0.8 pCi/L.
What a mitigation contractor does, in plain terms A radon mitigation contractor evaluates the house, designs the system, installs it, and verifies performance.
Evaluation: We begin by walking the property, inspecting the foundation type, looking for sump pits, slab cracks, crawlspace vents, and the route where piping will exit. Soil type matters, but in practice the mitigation approach is determined more by the foundation and interior layout than by soil alone. I also look for mechanical or moisture issues to avoid creating new problems when we install the system.
Design: A common solution is active soil depressurization, a fan-driven system that pulls soil gas from beneath the slab or from a sub-slab collection point and vents it above the roofline. For homes with crawlspaces we often combine crawlspace encapsulation with a venting fan. For poured- and block-wall basements the collection points and piping layout differ. The contractor should explain where the piping exits the house, how the fan will be mounted, and where the manometer or monitor will be located.
Installation: Typical steps include creating a suction pit or using suction points drilled through the slab, running PVC piping up and out through the roof or siding, sealing major entry pathways such as large cracks and joints, and mounting the fan. We always try to minimize cosmetic damage by routing piping along unobtrusive walls and using paintable pipe covers when appropriate.
Verification: After the system runs, a post-mitigation test confirms reduced levels. Industry practice is to test after 24 hours of continuous operation and again over a longer period, depending on local protocols. A visible gauge such as a manometer shows the system is working; electronic monitors provide continuous readings if the homeowner wants constant feedback.
How effective are radon systems? When properly designed and installed, active soil depressurization typically reduces indoor radon by 90 percent or more. Expectations vary with the starting concentration and house characteristics. For example, if a home tests at 20 pCi/L and a system removes 90 percent, indoor levels drop to around 2 pCi/L. Systems rarely eliminate radon entirely, but the goal is to get levels well below action thresholds.
Costs and what drives them Costs vary by region and by job complexity. In the St. Louis area, common price ranges for a standard sub-slab depressurization system are about 800 to 2,500 USD, though older foundations, multiple suction points, or challenging roof penetrations can raise that. Additional work such as crawlspace encapsulation, sealing large openings, or replacing a failed sump lid will add to the bill.
Key cost drivers include foundation type, accessibility, number of fans needed, and local code requirements. A walk-out basement with easy exterior access and a single large slab area is quicker and less expensive to mitigate than a house with multiple small slabs or extensive block foundation voids. Permit fees and contractor licensing or certification may also affect final pricing.
Timing and disruption Most straightforward installs take four to six hours for a single technician. When additional work is required, such as cutting into an interior slab, running piping through finished walls, or encapsulating a crawlspace, a job can span a full day or two. I always tell clients to expect noise from the fan for a day or two while we test, and minor dust while we drill or cut, but overall the disruption is small compared with many other home projects.
Choosing a contractor Look for practical experience, local references, and clear communication. Licensing requirements vary by state and municipality, so check local rules. Ask a potential contractor to show before-and-after test results from jobs like yours, explain their guarantee or warranty, and describe what follow-up testing they will perform. A contractor should be willing to explain why a particular approach fits your house instead of defaulting to one system type for every home.
A checklist I give homeowners before hiring someone
Ask for a written estimate that breaks down labor, materials, permit fees, and post-mitigation testing. Request references and ask to see before-and-after test data from similar foundations. Confirm whether the contractor carries liability insurance and workers compensation. Verify the proposed fan model and expected operating noise level, and ask about fan life expectancy. Understand the warranty and what maintenance, if any, is required.System types and trade-offs Active sub-slab depressurization is the most common and broadly effective method. For homes with crawlspaces, encapsulation combined with a fan that vents to the outside works well because it addresses both radon and moisture. In rare cases where exterior venting is impossible, systems can be routed through other locations, but venting must be above the eave line and away from windows to avoid re-entry. Fans are typically inline or stack-mounted on the roof. Inline fans are quieter when installed outside the conditioned living space; attic-mounted fans risk heat and freezing issues depending on climate and insulation.
Trade-offs include cost, visibility of piping, and maintenance. Piping visible along a basement wall is easy to access and maintain, but some homeowners prefer hidden routes. Hiding pipe often requires cutting through walls or chasing conduit, which adds time and cost. Fans have finite lifespans; most quality radon fans last 5 to 15 years depending on usage and model. I recommend homeowners budget for eventual fan replacement and consider installing a convenient shut-off switch or labeled circuit so future maintenance is straightforward.
How long does a fan run Fans are meant to run continuously. Turning a system off for long periods allows radon to rebound. Short interruptions for maintenance or if the homeowner is away briefly are manageable, but the system should otherwise be left on. Continuous operation also lets the gauge or monitor show consistent depressurization and gives better assurance that levels remain low.
Permits, codes, and roof penetrations Local codes address how high above the roofline a vent must be, and placement relative to doors and windows. A reputable contractor will pull required permits and follow venting standards to prevent radon from re-entering the house. Roof penetrations should be flashed and sealed to prevent leaks. I have reworked several DIY attempts where poor flashing led to water intrusion; when in doubt, have a pro handle the roof work.
Testing after mitigation After installation, perform a follow-up test to verify results. Industry practice often includes a short-term test after 24 hours of continuous operation and a longer-term test to capture variations. If the post-mitigation short-term test still reads above the action level, the contractor should troubleshoot: check the manometer, look for additional suction points, test possible leaks, and consider increasing fan capacity or adding a second suction point.
Common homeowner misconceptions Radon is only a basement problem: False. While basements and lower levels typically show the highest concentrations, radon can accumulate on upper floors if the house stack effect draws soil gas upward. Sealing basement floors without an active system may lower entry points but can also concentrate radon in other areas if not done correctly.
My house is new so I do not need mitigation: New houses can still have elevated radon, especially if built on radon-prone soil. Modern construction sometimes seals homes so tightly that any radon that does enter remains trapped.
A cheap do-it-yourself unit will solve it: There are DIY kits and passive vents, and in some low-level cases passive measures can reduce radon marginally. For levels above typical action thresholds, active fan-driven systems designed to the specific house perform far better. I have evaluated failed DIY attempts where fans were undersized, piping leaked, or vents were placed too low.
Maintenance and long-term considerations Most maintenance is minimal. Inspect external piping for cracks or disconnections annually, check the manometer to ensure the vacuum is within radon system repair expected range, and listen for abnormal fan noise. Replace the fan when it fails. If you live in a climate with freezing temperatures, ensure the fan and piping are protected from ice or condensation that could block the line.
For resale, keep records. Buyers and inspectors will want to see pre- and post-mitigation test results, the system diagram, and warranty information. A well-documented mitigation job can be a selling point because it shows the home’s indoor air quality has been addressed.
Specifics for St. Louis and local considerations St. Louis lies in a region with a known tendency for elevated radon in many neighborhoods. Soil types and the prevalence of basements make mitigation common here. If you search online for radon mitigation St Louis or Stl radon, you will find numerous contractors, but vet them carefully. Local contractors who have installed hundreds of systems will know common foundation quirks in your area, where to route pipe along historic brickwork, and how to handle older block foundations without creating moisture problems.
If a home inspector or buyer brings up radon during a transaction, decide quickly but thoughtfully. Short-term tests are typically used in real estate transactions because they are fast. If the short-term test shows levels above action thresholds, request an estimate from a qualified radon mitigation contractor and plan for post-mitigation testing before closing, or include contingency language in your offer that addresses negotiation points when radon is elevated.
Edge cases and harder problems High-rise condos, units without direct roof access, and certain historic preservation situations can present challenges. For condos, mitigation may require building-level solutions coordinated with the association. Historic homes may restrict visible piping on façades; in these cases workarounds include routing piping internally and painting to match finishes, or collaborating with preservation authorities on acceptable external routes.
For homes with extremely high initial levels, sometimes a single suction point is not enough. We may need multiple suction pits, larger-diameter piping, or multiple fans. In a house I worked on that tested above 50 pCi/L, we used two suction points tied to a single larger fan and achieved a reduction to under 3 pCi/L.
Final practical advice Test first, then plan. If levels are elevated, hire a licensed or certified mitigation contractor who will provide a clear written plan and warranty. Expect a straightforward install in most cases, but be ready to invest a little for quality work that runs continuously. Keep records, schedule simple annual checks, and budget for fan replacement every decade or so. If you live near St. Louis, include local search terms such as Radon mitigation near me or Radon mitigation contractor St Louis to find installers, but judge candidates on experience and documentation rather than advertising alone.
Radon mitigation is one of those home improvements that yields outsized value for modest cost. You reduce health risk, preserve your house’s comfort, and gain peace of mind with a solution that is measurable, provable, and maintainable. If you have specific test results or photos of your foundation details, share them with a contractor for the most accurate evaluation and a tailored estimate.
Air Sense Environmental – Radon Mitigation & Testing
Business Name: Air Sense Environmental – Radon Mitigation & TestingAddress: 5237 Old Alton Edwardsville Rd, Edwardsville, IL 62025, United States
Phone: (618) 556-4774
Website: https://www.airsenseenvironmental.com/
Hours:
Monday: 9:00 AM – 5:00 PM
Tuesday: 9:00 AM – 5:00 PM
Wednesday: 9:00 AM – 5:00 PM
Thursday: 9:00 AM – 5:00 PM
Friday: 9:00 AM – 5:00 PM
Saturday: Closed
Sunday: Closed
Plus Code: RXMJ+98 Edwardsville, Illinois
Google Maps URL: https://maps.app.goo.gl/XTPhHjJpogDFN9va8
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Popular Questions About Air Sense Environmental – Radon Mitigation & Testing
What services does Air Sense Environmental provide?
Air Sense Environmental provides professional radon testing, radon mitigation system installation, indoor air quality solutions, and crawl space encapsulation services in Edwardsville, Illinois and surrounding areas.Why is radon testing important in Illinois homes?
Radon is an odorless and invisible radioactive gas that can accumulate indoors. Testing is the only way to determine radon levels and protect your household from long-term exposure risks.How long does a professional radon test take?
Professional radon testing typically runs for a minimum of 48 hours using continuous monitoring equipment to ensure accurate results.What is a radon mitigation system?
A radon mitigation system is a professionally installed ventilation system that reduces indoor radon levels by safely venting the gas outside the home.How do I contact Air Sense Environmental?
You can call (618) 556-4774, visit https://www.airsenseenvironmental.com/, or view directions at https://maps.app.goo.gl/XTPhHjJpogDFN9va8 to schedule service.Landmarks Near Edwardsville, IL
Southern Illinois University Edwardsville (SIUE)A major public university campus that serves as a cultural and educational hub for the Edwardsville community.
The Wildey Theatre
A historic downtown venue hosting concerts, films, and live entertainment throughout the year.
Watershed Nature Center
A scenic preserve offering walking trails, environmental education, and family-friendly outdoor experiences.
Edwardsville City Park
A popular local park featuring walking paths, sports facilities, and community events.
Madison County Transit Trails
An extensive regional trail system ideal for biking and walking across the Metro East area.
If you live near these Edwardsville landmarks and need professional radon testing or mitigation, contact Air Sense Environmental at (618) 556-4774 or visit https://www.airsenseenvironmental.com/.