Before you start
The real PL01 is 150 items across three portions — 100 code and trade knowledge questions plus two 25-item drawing portions — with 70% required on each portion, closed book. These ten questions sample the multiple-choice style across nine chapters of the 2015 UPC.
They come from JourneyWorthy's verified content bank: original questions written to the 2015 UPC + Washington amendments and verified by trade professionals. They are not real exam items — nobody outside PSI has those, and anyone claiming otherwise is selling you something.
Treat 7/10 as the bar. That's the 70% the real exam demands — portion by portion, with no code book on the desk.
How to read your score
- 9–10: strong on sampled code knowledge — now pressure-test it at full length. The real Part 1 is 100 items in 90 minutes, and the drawing portions are a different skill entirely.
- 7–8: you'd clear today's bar, barely. The exam gives no partial credit for "close" — and the waste & vent portion is where prepared candidates still stumble.
- 6 or below: you've just saved yourself money. A real attempt costs about $282 and a failed portion means a 14-day wait and a new application. Study first, sit second.
What these 10 questions can't show you
Two of the three PL01 portions aren't multiple-choice trivia at all — they're drawing-based sizing exercises: 25 waste & vent items and 25 water sizing items, each portion 90 minutes. The waste & vent portion in particular is the one L&I's advisory-board transcripts flag as the common failure point, partly because the sizing table it depends on (Table 703.2) is not provided at the exam. Start with the complete exam guide, then read the waste & vent deep-dive.
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SOURCES
- Washington L&I — Plumber Examination — code edition, fees, and exam policies. (checked July 2026)
- PSI — Washington Plumbing examinations — Candidate Information Bulletin: portion structure, 70% passing score, closed-book policy. (checked July 2026)
- WAC 51-56 — Washington State amendments to the Uniform Plumbing Code.
Question content is original JourneyWorthy material written to the 2015 UPC and verified by trade professionals — never reproduced code text and never actual exam items.