Radon Testing & Mitigation in Affton, MO

Air Sense Environmental provides radon testing, radon mitigation, indoor air quality testing and crawl space encapsulation in Affton, 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 Affton, 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 Affton 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. Affton is an unincorporated south St. Louis County community built mostly between the 1940s and 1960s, so its brick bungalows and ranches sit on full basements that are now 60 to 80 years old.

Radon varies house by house rather than neighborhood by neighborhood. Two homes on the same Affton 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 Affton, MO

Radon testing in Affton 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 Affton, MO

Radon mitigation in Affton 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 the St. Louis radon mitigation services page for the process, documented results and warranty.

Indoor air quality testing in Affton, MO

Indoor air quality testing in Affton 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 Affton, MO

Crawl space encapsulation in Affton 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 Affton homes does Air Sense Environmental work on?

The Affton homes the team sees most often:

• Brick bungalows and ranch homes from the 1940s to 1960s with full basements
• Homes with finished basement rec rooms and bedrooms, where the lowest level is lived in daily
• Older homes with floor drains and unsealed sump pits
• Any home changing hands along the Gravois Road corridor

What should Affton 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.

Affton neighborhoods and nearby communities

Air Sense Environmental works across Affton, MO, including the Gravois Road corridor and the neighborhoods around Grant’s Farm, in ZIP code 63123. Nearby communities with their own service pages:

• Radon testing and mitigation in Webster Groves, MO
• Radon testing and mitigation in Oakville, MO
• Radon testing and mitigation in Kirkwood, MO
• Radon testing and mitigation in St. Louis, MO
• All Air Sense Environmental service areas

From Our Work