Oregon Plumbing Code and Regulations
This domain tests Oregon law and administration rather than trade technique: which code applies, who may do the work, what permits and inspections are required, and where Oregon amends the model code.
The code and who enforces it
Oregon plumbing law is in ORS chapter 447, with administrative rules in OAR chapter 918. The Oregon Building Codes Division adopts the Oregon Plumbing Specialty Code (OPSC), which is the Uniform Plumbing Code as amended by Oregon. Cities and counties with approved programs issue permits and perform inspections locally; BCD administers the code where no local program exists. Always answer from the OPSC, not from the unamended model code.
Licensing and permits
Plumbing work must be done by a licensed journeyman or master plumber, or by a registered trainee under supervision. Contracting for plumbing work requires the proper contractor licensing. Oregon provides a limited owner exemption for plumbing in the owner's own single-family residence, but it does not remove permit, inspection, or code-compliance duties, and it does not cover rental property or work for compensation. A permit is required before work begins, a rough-in inspection before pipe is covered, and a final inspection at completion.
Oregon-specific items
Water heaters must be secured against seismic movement, typically with upper and lower straps. Backflow assemblies must be tested by testers certified under Oregon Health Authority rules. Water heater replacement requires a permit, a full-size T&P discharge terminating safely, and expansion control on a closed system.
Worked example
An owner replaces a 50-gallon water heater in a rented duplex. The owner exemption fails because the property is a rental, so a licensed plumber and a permit are required. The install needs seismic strapping, a T&P line run full size to within 6 in of the floor, and an expansion tank if the system is closed, followed by inspection. Reasoning: identify occupancy and who performs the work first, then layer on the installation requirements.
Traps
Studying only the UPC, assuming license reciprocity, skipping the rough-in inspection, and applying the homeowner exemption to rentals are the common misses.