Building Code Guides (BCGs) and Building Official Determinations (BODs) provide answers about the application of building codes and outline optional alternates. BODs are typically smaller in scope and address simpler questions. Code Guides provide a comprehensive alternative to a complicated set of code requirements.
BOD 13-01: HDPE Sewer Pipe
QUESTION: Can high-density polyethylene (HDPE) sanitary sewer pipe material be used for building drain pipe as an alternative to approved pipe materials listed in Chapter 7 of the Oregon Plumbing Specialty Code (OPSC) when the pipe will be under an existing building foundation and/or inside an existing building envelope?
RESPONSE: Yes, provided the HDPE pipe is clearly marked as being HDPE material and the HDPE material extends not more than 18 inches interior to the exterior wall of an existing building.
The OPSC limits the materials that can be used for sanitary sewer drainage pipes to those specifically listed in Chapter 7. Any material not included on that list may not be used, unless it provides equivalent or superior quality, strength, fire resistance, effectiveness, durability and safety over those prescribed by the OPSC. Chapter 7 of the OPSC also prohibits sewer or other drainage piping that is made of materials other than those approved for use within a building from being installed under or within five feet of any building or structure.
The City of Portland has determined that HDPE pipe material meets the equivalency requirements of the OPSC for use in sanitary sewers for existing buildings and may be used in lieu of other listed materials under the following conditions:
- The HDPE material may extend up to but not more than 18” interior to the building envelope, measured from the exterior building wall as defined in the Oregon Structural Specialty Code (OSSC); and
- The HDPE material shall be clearly marked “HDPE”; and
- The HDPE pipe shall be connected to the existing piping with an approved flexible drawband connection device.
Use of HDPE pipe that extends further than 18” interior to the building envelope as measured from the exterior wall will be reviewed and considered on a case-by-case basis through the administrative appeals process.
HISTORY: Implemented October 11, 2013. Revised May 30, 2024.
DOWNLOAD a copy of this Building Official Determination:
QUESTIONS? Free 15-Minute Appointments for Permit, Code, and Zoning Questions