Collection and separation
A suction point accesses soil gas below a slab. In a crawl space, a sealed membrane may create the pressure boundary. Sumps and drains need details that preserve drainage and serviceability.
Movement and discharge
Pipe conveys soil gas; an in-line fan may maintain negative pressure. Route and discharge details must be chosen for the building, weather, openings, service access, and applicable requirements.
Indicators and alarms
A manometer or other indicator can show a pressure relationship. Its normal reading is system-specific and is not pCi/L. Some systems may include alarms, but periodic radon measurement remains important.
Primary sources
Claims checked August 2, 2026. Guidance can change; confirm the current source before acting.