Crawl Space Radon Mitigation in Colerain Township, OH

Half of Colerain Township's homes were built between 1947 and 1967. The township's housing plan put the median home at close to 50 years old and counted 81 percent of units as single-family houses, so the usual radon job here is a postwar basement now roughly 60 to 80 years old, commonly on a slab poured with no membrane beneath it and carrying decades of shrinkage cracks, each one a soil-gas path to seal. Subdivisions built since then more often come with a sump that can double as the suction point. With about half its land wooded and 15 percent farmed as of 1990, the township can also turn up rural houses where a crawl space or an older foundation calls for a membrane or wall sealing rather than a single floor penetration. Colerain Township spreads across 42.9 square miles of northern Hamilton County, gentle wooded hills that divide the Mill Creek and Great Miami River basins; John Dunlap settled Dunlap's Station on a bend of the Great Miami in 1790, and the villages of Barnesburg, Bevis, Dunlap, and Groesbeck grew up along Blue Rock and Colerain roads in the early 1800s. Colerain Township sits on the Cincinnati Arch geology (fractured Ordovician limestone and shale) that drives elevated regional radon exposure across the entire Greater Cincinnati metro, including Hamilton County.

Colerain Township's ZIP 45247 has 1,016 Ohio Department of Health test records since 2010, with a median of 2.3 pCi/L and 25% above 4.0. Those numbers mix basements, slabs, and crawl spaces, so a crawl-space house needs its own test on the lowest lived-in floor before a membrane is designed.

Crawl-space work in Hamilton County is the exception rather than the rule inside Cincinnati proper, where full basements dominate, but it becomes the standard scope on the county's hillside and outlying parcels where a home was built into a slope rather than over a dug basement, and the membrane has to seal to an irregular hillside foundation wall rather than a straight rectangular perimeter.

ANSI/AARST SGM-SF-2023, the standard for existing homes, calls for a sealed membrane and a system monitor, typically a manometer, showing continuous negative pressure beneath it. The Ohio Department of Health Radon Licensing Program oversees radon program compliance for Colerain Township, and Ohio licensure under ORC 3723.02 applies to any contractor performing mitigation work in the state.