# Commercial Radon Mitigation in St. Louis, MO

- **URL:** https://airsenseenvironmental.com/commercial-radon-mitigation/
- **Published:** 2026-07-20

Skip to content Radon Mitigation Services ▾ Radon Testing Commercial Radon Mitigation Commercial Radon Testing Indoor Air Quality Crawl Space Encapsulation Service Area Resources FAQ Blog Podcast Reviews & Projects About Us Contact 314-664-9807 Free Estimate Radon Mitigation Services Radon Testing Commercial Radon Mitigation Commercial Radon Testing Indoor Air Quality Crawl Space Encapsulation Company Service Area Resources FAQ Blog Podcast Reviews & Projects About Us Contact Call 314-664-9807 St. Louis Metro · Missouri & Illinois Commercial Radon Mitigation in St. Louis, MO Offices & Retail Apartments & Multi-Family Schools & Daycares Warehouses & Medical Commercial radon mitigation reduces radon inside business, institutional and multi-family buildings to below the EPA action level of 4.0 pCi/L using multi-point sub-slab depressurization engineered for the building's footprint, foundations and HVAC. Air Sense Environmental tests, designs, installs and verifies commercial radon mitigation systems across the St. Louis metro in Missouri and Illinois, and delivers the documentation lenders, insurers, tenants and state licensing inspectors ask for. Call 314-664-9807 Request a Building Assessment IEMA License #RNM20232346 NRPP-Certified Documented Verification Testing Commercial Performance Target EPA action level4.0 pCi/L Design target< 2.0 pCi/L Every monitored location is retested after installation and documented against 4.0 pCi/L. Verified per location Definition What is commercial radon mitigation? Commercial radon mitigation is the engineered process of reducing radon gas concentrations in business properties, including offices, multi-family buildings, schools, daycares, retail spaces, warehouses and medical facilities, to levels at or below the EPA action threshold of 4.0 pCi/L. Unlike a residential system, commercial mitigation must account for larger building footprints, multiple foundation slabs poured at different times, HVAC systems that can pull soil gas into the building, and ongoing documentation requirements for tenants, insurers, lenders and state regulators. Air Sense Environmental designs and installs IEMA-licensed commercial radon systems across the greater St. Louis metro in both Missouri and Illinois. Commercial systems in the field: multi-point sub-slab piping and inline fans sized for the building, not for a house. Buildings Which buildings need commercial radon mitigation in St. Louis? Any occupied building sitting on the limestone and shale that underlies the St. Louis metro can test above 4.0 pCi/L, and about one in three Missouri homes does. Commercial buildings see the same soil gas with a larger slab to seal. Offices and retail: slab-on-grade buildings where the HVAC return can depressurize the floor and draw radon in. Apartments and multi-family: ground-contact units carry the exposure, and HUD-financed properties must test before financing and mitigate units that read high. Schools and daycares: Illinois requires licensed day care centers to test at least every three years and to mitigate on a high result. Warehouses and light industrial: large slabs with expansion joints that need several suction points to depressurize. Medical and dental: long-occupancy treatment rooms on the lowest level, often with strict documentation needs. Multi-Family Radon mitigation systems for apartment buildings A radon mitigation system for apartments treats each ground-contact unit or each foundation section as its own zone, because one suction point rarely reaches across a footing-separated slab. Testing comes first: continuous monitors go into ground-floor units and a sample of upper units, then the results map which zones need active depressurization. Air Sense Environmental installs multi-family systems riser by riser so residents stay in place, routes exhaust above the roofline away from windows and air intakes, labels every fan and manometer, and retests each mitigated unit. Property managers receive the per-unit results and system map in one package for the lender or the insurer. Exterior riser and fan on a St. Louis area commercial installation. Components Components of a commercial radon mitigation system A commercial radon mitigation system combines several suction points, one or more inline fans sized to the sub-slab conditions, sealed slab penetrations, exhaust risers terminating above the roofline, and a manometer on every system so facilities staff can confirm operation at a glance. Multi-point sub-slab depressurization: the core method, with suction points placed after pressure field extension testing across the slab. HVAC-integrated mitigation: balancing building pressure so the ventilation system stops pulling soil gas in. Block wall depressurization: for hollow-block foundation walls that act as radon chimneys. Crawl space encapsulation and ventilation: sub-membrane depressurization where part of the building sits over a crawl space. Continuous radon monitors: deployed for the pre- and post-mitigation measurements at every zone. Verification Verified performance and documented compliance Commercial radon mitigation is finished when the post-mitigation measurements at every monitored location are documented below 4.0 pCi/L, not when the fans turn on. Air Sense Environmental retests each zone after installation and issues a report covering pre- and post-mitigation results, a system diagram, fan specifications and the recommended retest schedule. That package satisfies the documentation asked for in HUD multifamily transactions, Illinois day care licensing inspections, commercial property sales and tenant requests. Where a building only needs measurement first, see commercial radon testing. Coverage Where we provide commercial radon services Air Sense Environmental provides commercial radon testing and mitigation throughout the St. Louis metro: St. Louis City and County, St. Charles, Jefferson and Franklin counties in Missouri, and Madison and St. Clair counties in Illinois, from the headquarters at 5237 Old Alton Edwardsville Rd, Edwardsville, IL 62025. Illinois work is performed under IEMA license #RNM20232346; Missouri work is performed to the same NRPP-certified standard. See the full service area. Common Questions Frequently Asked Questions About Commercial Radon Mitigation Does Illinois require commercial buildings to test for radon? Illinois requires licensed day care centers to test for radon at least every three years and to share the results with parents, and it requires anyone performing that measurement or any mitigation to hold an IEMA license. Schools, offices and other commercial buildings are not required to test, but lenders, insurers and tenants increasingly ask for a result. Air Sense Environmental holds IEMA license #RNM20232346. How is commercial radon mitigation priced? Commercial radon mitigation is priced per building after a site assessment, not from a rate card, because the footprint, the number of foundation slabs, the sub-slab material and the HVAC configuration decide how many suction points and fans the design needs. Air Sense Environmental provides a written proposal after diagnostic testing, with the performance target and the follow-up test written in. Will radon mitigation disrupt tenants or operations? Most commercial installations run during business hours with no shutdown, because the work is concentrated at the slab penetration points and the exterior vent route. Multi-family buildings are typically completed unit by unit or riser by riser so residents are not displaced. Noise is limited to core drilling for a few minutes per suction point. What standard applies to radon mitigation in large and multifamily buildings? The ANSI/AARST radon mitigation standards for schools and large buildings and for multifamily buildings govern commercial and apartment work, covering system design, fan placement, exhaust location, labeling and post-mitigation verification. Air Sense Environmental designs and documents commercial systems to those standards. What documentation do I receive after commercial radon mitigation? You receive the pre-mitigation and post-mitigation test results for every monitored location, a system diagram showing suction points and fan locations, the fan specifications, and a labeled manometer at each system so facilities staff can confirm the fan is operating. That package is what lenders, insurers and licensing inspectors ask for. Commercial Buildings Request a commercial radon assessment in St. Louis Testing comes first. Air Sense Environmental measures the building, then proposes a system with the performance target and follow-up test in writing. Request a Building Assessment 5237 Old Alton Edwardsville Rd Edwardsville, IL 62025 314-664-9807 · Open 24 hours IEMA License #RNM20232346 Services Radon Mitigation Radon Testing Commercial Radon Radon Fan Replacement Sub-Slab Depressurization Crawl Space Encapsulation Company About Us Service Area Reviews & Projects FAQ Resources Contact © 2026 Air Sense Environmental. All rights reserved. Radon Mitigation & Testing · St. Louis, MO & Metro East, IL