Radon Testing & Mitigation in Webster Groves, MO

In Webster Groves, MO, Air Sense Environmental tests homes for radon, installs radon mitigation systems, tests indoor air quality and encapsulates crawl spaces. Every radon job in St. Louis County is measured against the EPA action level of 4.0 pCi/L, and the team is NRPP-certified and IEMA-licensed (#RNM20232346).

Is radon a problem in Webster Groves, 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 Webster Groves 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. Webster Groves is one of the oldest suburbs in St. Louis County, where 1890s to 1930s homes around Old Webster sit on stone and early poured foundations with cellars and partial basements.

A Webster Groves neighbor’s reading is a signal, not an answer. The soil under one lot, the cracks in one slab and the way one sump pit was sealed decide the number, which is why two similar homes a few doors apart can land on opposite sides of the action level.

Radon testing in Webster Groves, MO

A Webster Groves radon test runs 48 hours under closed-house conditions on a calibrated continuous monitor, and the report shows the hourly data as well as the average. The St. Louis radon testing page covers how the test works, and the radon testing cost guide holds current pricing.

Radon mitigation in Webster Groves, MO

When a Webster Groves home tests at or above 4.0 pCi/L, the same team designs and installs the radon mitigation system, usually in a single day, and retests to confirm the home is below the action level. See radon mitigation in Webster Groves for the process, documented results and warranty.

Indoor air quality testing in Webster Groves, MO

An indoor air quality assessment for a Webster Groves home logs particulate matter, chemical vapors, CO2, CO and humidity at one-minute intervals for 48 hours or more, so the fix is based on data. Details are on the St. Louis indoor air quality testing page.

Crawl space encapsulation in Webster Groves, MO

For Webster Groves homes with a crawl space, encapsulation lays a sealed vapor barrier over the soil and walls and adds humidity control, keeping damp air and soil gas out of the rooms above. Read more on the St. Louis crawl space encapsulation page.

Which Webster Groves homes does Air Sense Environmental work on?

The Webster Groves homes the team sees most often:

• 1890s to 1930s homes near Old Webster with stone foundations
• 1920s bungalows with partial basements and crawl spaces
• Mid-century ranches with finished basements
• Additions built over crawl spaces on older homes

What should Webster Groves 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.

Webster Groves neighborhoods and nearby communities

Air Sense Environmental works across Webster Groves, MO, including Old Webster, Old Orchard and the neighborhoods around Webster University, in ZIP code 63119. Nearby communities with their own service pages:

• Radon testing and mitigation in Kirkwood, MO
• Radon testing and mitigation in Rock Hill, MO
• Radon testing and mitigation in Maplewood, MO
• Radon testing and mitigation in Affton, MO
• All Air Sense Environmental service areas

From Our Work