Radon Testing in Kirkwood, MO

Radon testing in Kirkwood, MO measures how much radon gas has built up inside a home, reported in picocuries per liter (pCi/L) against the EPA action level of 4.0 pCi/L. Air Sense Environmental places a calibrated continuous radon monitor in Kirkwood homes for a 48-hour closed-house test and delivers a documented report, so buyers, sellers and homeowners in St. Louis County know whether the house sits above the action level. Kirkwood radon testing starts with the number. A radon test is the only way to get that number for a specific Kirkwood address.

Is radon a problem in Kirkwood, 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 Kirkwood 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. Kirkwood is one of the oldest suburbs in St. Louis County, and much of its housing predates 1950, which means limestone and stone foundations, cellars and low crawl spaces that let soil gas move freely into the house.

Radon varies house by house rather than neighborhood by neighborhood. Two homes on the same Kirkwood 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.

Which Kirkwood homes should be tested for radon?

Every Kirkwood home should have at least one radon test, and the EPA recommends retesting every two years for homes with a mitigation system and after any major renovation. The homes Air Sense Environmental tests most often in Kirkwood, MO:

• Pre-1950 homes near Downtown Kirkwood with limestone or stone-block foundations
• Homes in Meacham Park and North Kirkwood with mixed foundation types and older sill plates
• Mid-century ranches with partial basements and crawl spaces under additions
• Newer infill and tear-down rebuilds on poured basements, which still need a baseline test
• Any home being bought or sold, where a radon test during the inspection period protects both sides of the deal

How does a radon test work in a Kirkwood home?

1. Monitor placement. A calibrated continuous radon monitor goes on the lowest level of the home that is or could be lived in, away from drafts, windows and exterior doors, following EPA and NRPP placement protocol. In Kirkwood, that usually means the basement, finished or not, because that is the level closest to the soil.
2. 48 hours of closed-house conditions. Windows stay closed and the HVAC runs normally while the monitor records hourly readings, with tamper detection so the result stands up in a real estate transaction.
3. A documented report. You receive the hourly data and the average reading against the 4.0 pCi/L action level, with a plain explanation of what the number means for your Kirkwood home.

How much does radon testing cost in Kirkwood, MO?

Radon testing prices in Kirkwood depend on the type of test and whether it is part of a real estate transaction. Air Sense Environmental publishes current pricing on its St. Louis radon testing cost guide and explains professional versus DIY testing on the main radon testing page, so the figures live in one place. Call 314-664-9807 for a quote for a Kirkwood address.

What happens if a Kirkwood radon test comes back at or above 4.0 pCi/L?

If the reading is at or above 4.0 pCi/L, the EPA recommends fixing the home, and the same Air Sense Environmental team designs and installs the system. See radon mitigation in Kirkwood, MO for how a sub-slab depressurization system is fitted to Kirkwood foundation types, and the St. Louis radon mitigation services page for the process, documented results and warranty. A post-mitigation test confirms the system brought the home below the action level.

Radon testing near Kirkwood: neighborhoods and nearby communities

Air Sense Environmental tests homes across Kirkwood, MO, including Downtown Kirkwood, the Kirkwood train station area and the neighborhoods around Kirkwood Park, in ZIP code 63122. Nearby communities with their own service pages:

• Radon testing and mitigation in Webster Groves, MO
• Radon testing and mitigation in Des Peres, MO
• Radon testing and mitigation in Ballwin, MO
• All Air Sense Environmental service areas

Related from Air Sense Environmental: Indoor Air Quality Testing and Reviews & Projects.

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