Red Seal Plumber Exam: How It’s Structured and What to Focus On
Plumber licensing in the US is state-by-state. The first thing you need to know is which plumbing code your state uses. For the Canadian version, see our Red Seal Plumber exam guide. For contractor licensing in NASCLA states, see our NASCLA Contractor exam guide.
IPC vs UPC: Which States Use Which?
~35 states use the IPC (eastern, midwest, southern). ~15 states use the UPC (western: California, Oregon, Washington, Montana, Idaho, Hawaii). A few use state-specific codes. If you move between IPC and UPC states, you will likely retake under the new code.
What the Exam Covers
DWV Systems: largest section. Pipe sizing, fixture units, trap sizing, venting methods, cleanouts, storm drainage. Sizing methods differ between IPC and UPC.
Water Supply and Distribution: pipe sizing, pressure, water heaters, backflow prevention, thermal expansion.
Fixtures and Appliances: installation requirements, ADA/ANSI A117.1 accessibility.
Gas Piping (many exams): sizing, materials, testing, appliance connections, venting, CSST installation. 10–15% of questions.
Code Calculations: pipe sizing, fixture unit counts, water demand (IPC uses Hunter’s curve; UPC uses different table), gas pipe sizing.
Open-Book Format
Most exams are open-book. Bring your own code book (IPC or UPC) with tabs, highlights, handwritten notes. Tab key tables before exam day. Practice navigating to entries in under 30 seconds.
The Plumber USA Journeyman Exam Prep book gives you 1,000 practice questions covering DWV, water supply, fixtures, gas piping, and code calculations. Covers principles that apply under both IPC and UPC with explanations noting where the two codes differ.
[Get the Plumber USA Journeyman Exam Prep book on Amazon →]
https://redseal-training.ca/plumber-2/
Frequently Asked Questions
What is the difference between IPC and UPC?
Two major US plumbing codes. Same topics, different specific requirements: fixture unit values, venting rules, pipe sizing methods. ~35 states use IPC, ~15 use UPC.
Is the exam open book?
Most are. Bring your own code book with tabs and notes. Test your ability to find and apply code sections quickly.
Which states use which code?
IPC: most eastern, midwest, southern states. UPC: primarily western states (CA, OR, WA, MT, ID, HI). Check your state licensing board.
