California C-36 Plumbing Contractor Exam Practice Exam
Free Practice Exam
Test your knowledge with 10 questions from our pool of 20 free questions.
- 10 questions per attempt
- 30 minute time limit
- Unlimited attempts
- A new mix each time
- Instant results
Full Practice Exam
Complete exam simulation matching the real PSI test format.
- 115 questions
- 210 minute time limit
- 5 topic areas covered
- 516 questions in pool
- Detailed explanations
Texts preferred · 9am–9pm Central
California C-36 Plumbing Contractor Practice Exam Guide
What's on the exam
Questions per topic, out of 115This practice exam is built around the official content outline for the California C-36 Plumbing Contractor exam: Planning and Estimating, Underground and Rough Systems, Finish Plumbing Installations, Service, Repair, and Remodel Plumbing Systems, Safety.
There are two ways to practice. The free practice exam gives you 10 questions per attempt, and you can take it as many times as you like. The full practice exam gives you 115 questions on a 210 minutes clock, with a new draw from our question bank each time.
Planning and Estimating — about 22% of the exam
The outline lists: Scope of work and code compliance; Pipe sizing and venting requirements; Shop drawings, plans, and specifications; Job site inspections; Coordination of projects; Water conservation; Cost estimation for materials, equipment, labor, and overhead. Our study plan adds: Fixture unit loading and drainage pipe sizing calculations.
Underground and Rough Systems — about 22% of the exam
Our study plan for this topic: Excavation and underground installations; Piping layout and installation; Fuel gas piping; Insulation and system testing; Sanitary drainage system design and pipe sizing; Vent system installation and termination requirements; Storm drainage systems and subsoil drains; Underground utility notification and dig-alert requirements (USA/811 compliance).
Finish Plumbing Installations — about 20% of the exam
The outline lists: Plumbing fixtures and appliances; Water heaters; Shut-off valves; Specialty installations; Industrial and commercial piping and sanitary systems. Our study plan adds: Water heater seismic strapping and anchorage requirements; Temperature and pressure relief valve installation and discharge piping; Combustion air supply methods for water heaters and fuel-burning appliances.
Service, Repair, and Remodel Plumbing Systems — about 19% of the exam
The outline lists: Troubleshoot plumbing issues; Isolate leaks and damage; Repair plumbing; Retrofit plumbing; Disposal of plumbing materials. Our study plan adds: Water heater permit requirements and inspection procedures; Accessibility compliance requirements during alterations and path of travel upgrades; Asbestos identification and safe work practices during plumbing repair and demolition.
Safety — about 17% of the exam
Our study plan for this topic: Personnel safety; Job site safety; Environmental safety; Injury and Illness Prevention Program (IIPP) requirements; Fall protection systems and guardrail standards; Confined space entry procedures and permit requirements; Excavation safety and cave-in protection systems; Hazard communication and Safety Data Sheets (SDS).
Sample 1 — Planning and Estimating
Question: Your plumbing rough-in is complete and the framer is ready to close the walls on a residential project. Under the residential mandatory measures, wall and floor framing shall not be enclosed when framing members exceed what moisture content?
- A. 19 percent
- B. 16 percent
- C. 15 percent
- D. 12 percent
Correct Answer: A
CALGreen Section 4.505.3 prohibits enclosing wall and floor framing when framing members exceed 19 percent moisture content. Readings are taken with a probe-type or contact-type meter, 2 to 4 feet from the grade-stamped end, with at least three random readings documented for the enforcing agency.
Reference: 2025 California Green Building Standards Code (CALGreen), Section 4.505.3
Sample 2 — Underground and Rough Systems
Question: A fixture trap holds water that seals the drainage system against sewer gas. The depth of that trap seal, measured between the top of the dip and the crown weir, must be:
- A. Not less than 4 inches, not more than 6 inches
- B. Not less than 3 inches, not more than 5 inches
- C. Not less than 1 inch, not more than 2 inches
- D. Not less than 2 inches, not more than 4 inches
Correct Answer: D
A standard trap seal is a minimum of 2 inches and a maximum of 4 inches deep. Deep-seal traps (used, for example, at some area drains to resist evaporation) are an exception permitted by code for specific applications.
Reference: Plumbing Technology: Design and Installation (4th ed.), Chapter 15, Traps
Sample 3 — Finish Plumbing Installations
Question: You are completing a masonry chimney serving a residential-type gas boiler. A second-story wall of the same building stands 8 feet horizontally from the chimney. What minimum termination heights apply?
- A. 3 feet above the roof penetration and 2 feet above the wall
- B. 2 feet above the roof penetration and 2 feet above the wall
- C. 2 feet above the roof penetration and 3 feet above the wall
- D. 3 feet above the roof penetration and 5 feet above the wall
Correct Answer: A
A chimney for residential-type or low-heat appliances must extend at least 3 feet above the highest point where it passes through the roof and at least 2 feet higher than any portion of a building within a horizontal distance of 10 feet.
Reference: 2025 California Mechanical Code, Section 802.5.4
Your first score is just a starting point. After every attempt, the results page shows how you did on each outline topic, so you can see what to work on next. Keep at it until you pass consistently.
- Start with the questions you know. Go through the whole exam once and bookmark anything you're unsure about. Our practice exams let you bookmark and come back.
- Circle back to your bookmarks on the second pass.
- Turn every miss into a lesson. After each attempt, look up each missed question's reference in your book and read the section.
| Questions | Not published by the board |
| Time limit | 210 minutes |
| Passing score | Not published by the board |
| Books in the exam room | Closed book (no books in the room) |
| Exam fee | $51.43 |
- Candidates receive a printed score report at the check-in location immediately after the examination, and scores are not given by telephone.
Source: Contractors State License Board Licensing Examination Information Guide — Plumbing (C-36). Check the bulletin before test day: fees and rules can change.