6 realistic open-book IPC questions for US journeyman plumber exams (Texas, Massachusetts + 18 more states) — 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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These 6 sample questions represent the type of questions you will encounter on the Texas and Massachusetts Journeyman Plumber exams. In Texas, the exam is administered by PSI for the Texas Department of Licensing and Regulation (state board): the IPC Knowledge line (59 questions) and the Calculations line (26 questions) are scored separately. In Massachusetts, the exam is administered by PSI for the Board of State Examiners of Plumbers: Part I (80 questions, 180 minutes) and Part II Applied (30 questions, 60 minutes), also open book against IPC. Both exam formats test 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 full exam content of the US (TX IPC code navigation and calculations, MA Part I and Part II Applied, plus every other state track). 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
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