6 realistic open-book IPC questions for the US journeyman plumber exam — with the exact code reference for every answer. Click to reveal the answer and explanation. Free practice starts with the first chapter of every exam in the app.
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Six real open-book questions covering the code areas the exam draws on — drainage slope, trap seal depth, vent terminal height, water heater T&P discharge, water supply fixture units and cleanout distance — each with the correct answer and the IPC article or table it comes from. No account is needed to work through all six.
These 6 sample questions represent the type of questions you will encounter on the US Journeyman Plumber exam — open book against the International Plumbing Code (IPC), with both the knowledge and calculations sections testing your ability to find and apply code rules, not to memorize them.
Click the Show Answer button under each question to see the correct answer, a detailed explanation, and the code reference. Use these questions to practice your code-navigation skills — chapter map, section numbering, and the index — and to identify areas that need more study.
PlumberPractice covers the exam content of the US journeyman plumber exam — IPC code navigation and calculations. Sign up for free to start with the first chapter of each exam part in your state.
What is the minimum slope for a horizontal drainage pipe 3 inches or smaller?
✅ Correct Answer: 1/4 inch per foot
IPC Table 704.1 requires 1/4 inch per foot for pipes 3 inches and smaller; 4 inches and larger may use 1/8 inch per foot.
Reference: IPC 704.1 · Table 704.1
What is the required water seal depth for a plumbing trap?
✅ Correct Answer: 2 to 4 inches
Every trap must have a liquid seal of not less than 2 inches and not more than 4 inches to block sewer gas.
Reference: IPC 1002.2
A vent terminal through a roof must extend at least how far above the roof?
✅ Correct Answer: 6 inches
Vent terminals must extend at least 6 inches above the roof, measured from the highest point of penetration.
Reference: IPC 905.4
Where must the T&P relief valve discharge pipe terminate?
✅ Correct Answer: 6 to 24 inches above the floor
The discharge pipe must terminate 6 to 24 inches above the floor with no threads and no shutoff valve.
Reference: IPC 504.6
A dwelling bathroom group (lavatory, water closet, tub/shower) adds approximately how many water supply fixture units?
✅ Correct Answer: 6 WSFU
A private bathroom group counts as about 6 water supply fixture units under the IPC fixture unit tables.
Reference: IPC 604.3 · Table E103.3(1)
A cleanout is required at the base of a soil stack and within what distance of the building sewer connection?
✅ Correct Answer: 10 feet
Cleanouts are required at the base of each stack and within 10 feet of the building sewer connection on the building drain.
Reference: IPC 707.2
Preparing state by state? See the journeyman plumber exam formats for Colorado, Georgia, Oklahoma, Utah and Vermont, or follow the 30-day study checklist.
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