Seashell driveway installation. What Is It? Installing a radon mitigation system.

Lee Gilliam upgrades a coastal house's gravel driveway to a seashell driveway. The gang plays "What Is It?" with a broom-shaped tool with spinning spiral wires. After losing his dog to lung cancer, a homeowner finds high radon levels in his home, raising health concerns. Ross Trethewey teams up with a radon technician to install a mitigation system to reduce the levels.