100+ Free WA Plumber Practice Questions
Pass your Washington Journeyman Plumber License Exam exam on the first try — instant access, no signup required.
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Key Facts: WA Plumber Exam
70%
Passing Score
WA L&I
~100
Exam Questions
PSI exam format
3 hrs
Time Limit
PSI
UPC 2015
Code Base
Washington adoption
The Washington journeyman plumber exam is administered through PSI and overseen by L&I. The exam has approximately 100 questions with a 3-hour time limit, requiring 70% to pass. Washington uses the UPC 2015 with state amendments — a key distinction from IPC states. The UPC requires a 4-inch minimum building sewer and does not permit AAVs.
About the WA Plumber Exam
Washington journeyman plumber licensing exam administered by PSI and overseen by L&I. Based on the Uniform Plumbing Code (UPC) 2015 with Washington State amendments. Washington is one of the western states that uses the UPC rather than the IPC, which affects building sewer minimums, AAV usage, and other provisions.
Questions
100 scored questions
Time Limit
3 hours
Passing Score
70%
Exam Fee
$189.80 (exam) + $227.90 (license) (Washington Department of Labor & Industries (L&I))
WA Plumber Exam Content Outline
Drainage Systems
Drain pipe sizing, fixture units (DFU), slope requirements, cleanouts, 4-inch minimum building sewer, indirect waste, and special drainage per UPC 2015 with WA amendments
Water Supply Systems
Water pipe sizing, WSFU calculations, backflow prevention (RPZ/DCVA/AVB), pressure regulation, water heaters, and cross-connection control
Venting Systems
Vent sizing (half-drain rule), wet venting, circuit venting, vent termination, frost closure prevention, and trap seal protection — no AAVs under UPC
Fixtures & Appliances
Fixture installation, clearances (24-inch front clearance per UPC), accessible fixtures, commercial fixtures, and scald prevention
Gas Piping
Gas pipe sizing, BTU calculations, appliance venting, pressure testing, CSST bonding, and combustion air requirements
Code Administration & Materials
L&I licensing, permits, inspections, approved materials, joint methods, UPC vs IPC differences, and Washington-specific amendments
How to Pass the WA Plumber Exam
What You Need to Know
- Passing score: 70%
- Exam length: 100 questions
- Time limit: 3 hours
- Exam fee: $189.80 (exam) + $227.90 (license)
Keys to Passing
- Complete 500+ practice questions
- Score 80%+ consistently before scheduling
- Focus on highest-weighted sections
- Use our AI tutor for tough concepts
WA Plumber Study Tips from Top Performers
Frequently Asked Questions
How hard is the Washington journeyman plumber exam?
The Washington exam is challenging with an estimated 50-60% pass rate. It has approximately 100 questions based on the UPC 2015 with WA amendments and requires 70% to pass. The UPC has different provisions than the IPC used by many other states.
What plumbing code does Washington use?
Washington uses the Uniform Plumbing Code (UPC) 2015 edition with Washington State amendments. The UPC is published by IAPMO and differs from the IPC in areas like building sewer minimums (4 inches vs 3 inches) and AAV usage (not permitted under UPC).
How much does the Washington plumber exam and license cost?
The total cost is approximately $417.70: $189.80 for the PSI exam fee plus $227.90 for the L&I license fee. Check with L&I for current fee schedules.
What key differences exist between the UPC and IPC?
Key UPC differences: 4-inch minimum building sewer (vs 3-inch IPC), no air admittance valves (AAVs), 24-inch front clearance for water closets (vs 21-inch IPC), and the half-drain-diameter vent sizing rule.