- Home
- Modules
- Storm Drainage (UPC ch. 11 / IPC ch. 11) — disposal, traps, roof drains and scuppers, sizing basis, subsoil drains
Storm Drainage Both Codes Agree On — Disposal, Conductors and Traps, Roof Drains, Secondary (Emergency) Drainage and Scuppers, the 100-Year Sizing Basis, Leader Capacities, Subsoil Drains and Subdrains, Testing (UPC ch. 11 / IPC ch. 11)
Storm water has its own system: roof drains and gutters feed vertical conductors (inside the building) or leaders (outside), which feed the building storm drain and storm sewer. Both codes agree on where the water may go, that storm and sanitary stay apart, when a storm trap is needed, how roofs get secondary (emergency) drainage, that sizing rests on the 100-year, 1-hour storm, and on the vertical-leader capacity table. They differ on the horizontal-drain tables, the subsoil-drain size and the sump details — §7, never tested.
2018 UPC and 2018 IPC · Reviewed 2026-09-20
1. Where storm water goes
- Rainwater from roofs and storm water from paved areas, yards and courts drains to a storm sewer (or a combined sewer where no separate storm sewer exists) or another approved place of disposal (UPC 1101.2; IPC 1101.2).
- One- and two-family dwellings may discharge storm water onto flat areas such as streets or lawns, provided it flows away from the building (and, UPC, away from adjoining property without nuisance) (UPC 1101.2; IPC 1101.2).
- Storm water is never drained into a sewer intended for sanitary sewage only (UPC 1101.3; IPC 1101.3).
- Conductors and leaders are never used as soil, waste or vent pipes, and soil, waste or vent pipes are never used as conductors (UPC 1101.16; IPC 1104.1).
- Inside the building the sanitary and storm systems are entirely separate (UPC 1101.16.2); with a combined public sewer the UPC joins the storm drain to the combined building sewer through a wye 10 ft downstream of any soil stack, the IPC connects the storm sewer independently to the public sewer (1109.1). Not tested.
Preview
This is where the public part ends.
The rest of this lesson, its quiz, all 1 lessons in the module and every mock exam open with the 7-day pass for $9. If you stay, it comes off lifetime.