1001.3 Placement and Minimum Size of Building Traps.
San Francisco Building Inspection Commission Codes · 2022 edition · ingested 2026-07-08 · San Francisco
1001.3 Placement and Minimum Size of Building Traps. The building sewer or building drain shall have a building trap placed as near as possible
t o t he curb line or immediately inside any subsidewalk basement wall under the sidewalk. Trap size shall be a minimum of 4 inches (101.6 mm).