Radon Testing & Mitigation in Clayton, MO

Air Sense Environmental provides radon testing, radon mitigation, indoor air quality testing and crawl space encapsulation in Clayton, MO. The company is IEMA-licensed (#RNM20232346) and NRPP-certified, works across St. Louis County from its Edwardsville, Illinois headquarters, and measures every radon job against the EPA action level of 4.0 pCi/L.

Is radon a problem in Clayton, MO?

Yes. St. Louis County is in EPA Radon Zone 2, where the predicted average indoor radon level is 2 to 4 pCi/L, and individual Clayton homes routinely test well above the 4.0 pCi/L action level. Missouri’s Department of Health and Senior Services reports that roughly one in three homes tested through its statewide program between 2003 and 2023 came back at or above 4.0 pCi/L. Clayton is the St. Louis County seat, where 1910s to 1930s homes in districts like Claverach Park and Wydown-Forsyth sit on older foundations a few blocks from high-rise condominiums.

Radon varies house by house rather than neighborhood by neighborhood. Two homes on the same Clayton street, built the same year by the same builder, can test at 1 pCi/L and 12 pCi/L because of what sits under each lot and how each foundation was sealed.

Radon testing in Clayton, MO

Radon testing in Clayton uses a calibrated continuous radon monitor for a 48-hour closed-house test, with hourly readings and tamper detection that hold up in a real estate transaction. The St. Louis radon testing page covers how the test works, and the radon testing cost guide holds current pricing.

Radon mitigation in Clayton, MO

Radon mitigation in Clayton means a sub-slab depressurization system designed around the specific foundation, with the fan outside the living space and a post-mitigation test to prove the result. See radon mitigation in Clayton for the process, documented results and warranty.

Indoor air quality testing in Clayton, MO

Indoor air quality testing in Clayton measures particulates, VOCs, carbon dioxide, carbon monoxide, temperature and humidity over at least 48 hours, with radon as an optional add-on, and ends in a written report. Details are on the St. Louis indoor air quality testing page.

Crawl space encapsulation in Clayton, MO

Crawl space encapsulation in Clayton seals the floor and walls with a reinforced vapor barrier, closes the vents and controls humidity with a dehumidifier, which also cuts off a common radon pathway. Read more on the St. Louis crawl space encapsulation page.

Which Clayton homes does Air Sense Environmental work on?

The Clayton homes the team sees most often:

• 1910s to 1930s homes in Claverach Park, Wydown-Forsyth and the Moorlands with older basements
• Large homes with finished lower levels and wine cellars
• Ground-floor and garden-level condominium units
• Tear-down rebuilds on deep poured foundations

What should Clayton homeowners expect?

1. Test first. A 48-hour continuous monitor test gives the number everything else depends on.
2. Read the report together. You get the hourly data and a plain explanation of what it means for the house.
3. Design the fix. If the reading is at or above 4.0 pCi/L, the system is designed around your foundation during a free in-home estimate.
4. Install and verify. Most systems go in within a single day, and a post-mitigation test confirms the result.

Clayton neighborhoods and nearby communities

Air Sense Environmental works across Clayton, MO, including Claverach Park, the Wydown-Forsyth district, the Moorlands and downtown Clayton, in ZIP code 63105. Nearby communities with their own service pages:

• Radon testing and mitigation in University City, MO
• Radon testing and mitigation in Richmond Heights, MO
• Radon testing and mitigation in Brentwood, MO
• Radon testing and mitigation in St. Louis, MO
• All Air Sense Environmental service areas

From Our Work