Guides · The ladder
Washington's PL01 is two licenses' worth of hours wearing one total: 8,000 hours, of which at least 4,000 must be commercial or industrial work.
Work on commercial and industrial premises and systems — the board's definitions govern, and they turn on the building and system, not the employer's letterhead. A trainee's file should record the premises type alongside the hours, because at application time the split must be provable.
A residential service trainee can work four full years and arrive at the window with 8,000 hours and half the commercial requirement. Employers do not always warn about this; the trainee's license is not the shop's asset. The rebalance — a rotation into commercial work — takes years to execute, which is why the time to check is year one or two, not year four.
Audit your own split now (the checker computes it). If commercial is thin, ask for the rotation in writing, or price a move to a mixed shop into your plan. Protect the registration either way: hours must be trainee hours under a certified journey plumber to count at all.
Full Washington rules: Washington ladder page.
