Sub Slab Depressurization Episodes

1 episode tagged with "Sub Slab Depressurization"

AI illustration of a basement slab with a sealed PVC radon pipe, hand tools, and dust in low daylight

Ask This Old House S24E2: Seashell Driveway, Radon Mitigation, and Why You Call a Pro

October 2, 2025 • 8 min read

Lee Gilliam rebuilds a coastal Massachusetts driveway with reclaimed stone edging and a 3-inch layer of local shells, keeping the hardpack base intact. Ross Trethewey and a certified mitigator diagnose a 100-year-old slab with grab samples and a manometer, then install a sub-slab depressurization system with an exterior fan wired by Heath Eastman.