Section 708.1/Cleanout Requirements
IPC 708 covers cleanout locations, spacing, sizing, and access provisions for drainage system maintenance.
Cleanouts must be installed at the upper terminus of every horizontal drain, at each change of direction exceeding 45 degrees, and at intervals not exceeding 100 feet for 4-inch and larger drains (50 feet for 3-inch and smaller). Each cleanout must be the same size as the drain it serves, up to 4 inches (4-inch cleanout for drains 4 inches and larger). Cleanouts must be accessible: they must not be covered by permanent finishes without an access panel. A cleanout at the building drain/sewer junction must be full-size (two-way cleanout or equivalent) to allow rodding in both directions.
Why this section exists
Drainage pipes accumulate grease, scale, and debris over time, eventually causing blockages. Cleanouts provide access points for mechanical cleaning equipment (drain snakes, hydro-jetting) to clear blockages without cutting into the piping. Without cleanouts at the required locations, a blockage in the middle of a long run or at a direction change requires destructive investigation to locate and access. The spacing and location requirements ensure every point in the drainage system is reachable from a nearby cleanout.
What plan reviewers look for
Plan reviewers check the plumbing plan for cleanout symbols at every horizontal drain terminus, at direction changes exceeding 45 degrees, and at the maximum spacing intervals. They verify the cleanout size matches the drain size. They check for the building drain cleanout at or near the point of exit. They verify cleanouts behind walls have access panels noted on the architectural drawings.