Free practice + study guide

CSLB Trade — Plumbing (C-36)

CSLB Plumbing (C-36) Trade Examination — Questions: Not published by CSLB · 210 minutes · Passing score: Not published by CSLB. CSLB's C-36 Plumbing study guide, form 13E-36 (03/2026) gives these approximate section weights: Planning and Estimating 22%, Underground and Rough Systems 22%, Finish Plumbing Installations 20%, Service, Repair, and Remodel Plumbing Systems 19%, Safety 17%. CSLB publishes section weights but no question count and no passing score for this exam. Last checked 2026-10-12. PrepPass also publishes a complete study guide for this exam as a downloadable book (290 pages, 200 practice questions inside, $14.99).

Your other CSLB exam

PrepPass Course: CSLB Law and Business

This license also needs the Law and Business exam (CSLB can waive an exam in some cases). 110 lessons, 732 practice questions.

Exam inside two weeks?

A printable colour cheat sheet for the exam: the format, the content areas and the figures it turns on, each checked against a named source and dated.

CSLB Class C-36 — Plumbing cheat sheet PDF — $9.99 →

4 pages · US Letter · printable PDF · yours to keep

01

Test what you know · free, all of it

Five ways to practise.

The same 360 questions, dealt five ways. Pick the one that fits the time you have.

02

Learn what the questions test

Practice finds the gaps. Reading closes them. The six chapters below are free to read online. The study guide book is a separate download, sold on its own page.

Practice · free
360
questions, each explained — finds what you don't know yet
Learn · the guide
290
pages in the study guide book, section by section

The six sections, as chapters

free to read online
  1. 1Planning, Plans, Permits & EstimatingPlanning & EstimatingRead free →
  2. 2Water Supply and DistributionWater Supply & DistributionRead free →
  3. 3Drainage, Waste and Vent (DWV)Drainage, Waste & VentRead free →
  4. 4Fixtures & Water HeatersRead free →
  5. 5Fuel Gas PipingGas PipingRead free →
  6. 6Job-Site SafetySafetyRead free →
Cover: CSLB Class C-36 Plumbing — Trade Exam Study Guide (2026)
Study guide · PDF + EPUB
CSLB Class C-36 Plumbing — Trade Exam Study Guide (2026)
290 pages · 200 practice questions inside · updated 2026-10-23
$14.99 one-time · yours to keep
03

Before you sit

Know the exam you're walking into.

04

See the questions first

Two from the bank, answered.

Real items, with the answer marked and the reason written out — the same format as all 360.

Drainage, Waste & Vent

What is the minimum slope for a 2 inch horizontal drainage pipe?

  1. A1/16 inch per foot
  2. B1/4 inch per footCorrect
  3. C1/2 inch per foot
  4. D1/8 inch per foot

Why: The CPC requires a minimum uniform slope of 1/4 inch per foot (about 2 percent) for horizontal drainage pipe 2-1/2 inches and smaller. The 1/8 inch per foot minimum is allowed only for pipe 3 inches and larger, so it is too flat for a 2 inch line. The 1/16 inch and 1/2 inch values are not the code minimum for this size.2022 California Plumbing Code (CPC) §708.1

Fixtures & Water Heaters

A temperature-and-pressure (T&P) relief valve on a residential storage water heater must be set to open at a temperature no higher than which value?

  1. A150°F
  2. B210°FCorrect
  3. C180°F
  4. D240°F

Why: A T&P relief valve protects the tank against overheating and must be rated so its temperature element opens at no more than 210°F. The pressure element is a separate rating. Both must be listed and approved for the appliance.2022 California Plumbing Code (CPC) §608.3

Read all 360 questions with answers →

06

The exam itself

CSLB Trade — Plumbing (C-36), by the numbers.

QuestionsNot published by CSLBCSLB says only that “All trade examinations consist of multiple-choice questions.” No count appears in the study guide, the Examinations FAQ, or PSI's candidate bulletin.
Time210 minutesCSLB: “You will be given 3-1/2 hours to complete each examination.” It is per examination, not per sitting — a candidate taking Law and Business plus a trade exam gets 3-1/2 hours for each.
SectionsPlanning & Estimating · Water Supply & Distribution · Drainage, Waste & Vent · Fixtures & Water Heaters · Gas Piping · Safety
Passing scoreNot published by CSLBCSLB: “You will be informed at the test site about the percentage of correct answers needed to pass each examination,” and, in Get Licensed to Build Q14, that the percentage “varies for each exam”. Passing candidates are never shown their own score. PrepPass states no passing score for this exam.
Our bank360 questions · updated August 2026Written from California Contractors State License Board (CSLB)
LanguagesEnglish · 中文 · Español
SourceCalifornia Contractors State License Board (CSLB)Verified 2026-10-12

Full facts and sources →

07

Helpful resources

The board's own page, and what else helps.

Apply / register — CSLB (official) →

Recommended prep — books & tools

  • Uniform Plumbing Code (UPC)

    The plumbing code California's C-36 trade exam is based on.

    See it on Amazon →
  • Ugly's Plumbing References

    Quick sizing charts and tables for exam calculations and the field.

    See it on Amazon →

This section contains affiliate links. As an Amazon Associate, PrepPass earns from qualifying purchases. We may earn a commission if you buy through these links, at no extra cost to you.

08

Contractor License Exams

On the same path.

09

Questions

Asked before starting.

Is the practice really free, or does it stop after a few questions?

All 360 questions, the timed mock and the report are free with no sign-up. A free account only adds saving your progress. The study guide book is sold separately, $14.99 one-time; nothing in the practice requires it.

Is your mock the same as the real CSLB Trade — Plumbing (C-36)?

No. Ours is 100 questions in 210 minutes; the real exam is 210 minutes long. Use the mock for stamina and section timing, not as a score predictor.

What score do I need?

Not published by CSLB. CSLB: “You will be informed at the test site about the percentage of correct answers needed to pass each examination,” and, in Get Licensed to Build Q14, that the percentage “varies for each exam”. Passing candidates are never shown their own score. PrepPass states no passing score for this exam.

What is on the CSLB Trade — Plumbing (C-36)?

CSLB's C-36 Plumbing study guide, form 13E-36 (03/2026) gives these approximate section weights: Planning and Estimating 22%, Underground and Rough Systems 22%, Finish Plumbing Installations 20%, Service, Repair, and Remodel Plumbing Systems 19%, Safety 17%. CSLB publishes section weights but no question count and no passing score for this exam. Last checked 2026-10-12.

Who administers the CSLB Plumbing (C-36) Trade Examination?

Contractors State License Board (CSLB), California Department of Consumer Affairs — exam delivered by PSI Services LLC. CSLB's legal existence is set by Business and Professions Code § 7000.5. CSLB states it has contracted with PSI to administer its examinations.

How many questions are on the CSLB Plumbing (C-36) Trade Examination?

Not published by CSLB. CSLB says only that “All trade examinations consist of multiple-choice questions.” No count appears in the study guide, the Examinations FAQ, or PSI's candidate bulletin.

How long is the CSLB Plumbing (C-36) Trade Examination?

210 minutes. CSLB: “You will be given 3-1/2 hours to complete each examination.” It is per examination, not per sitting — a candidate taking Law and Business plus a trade exam gets 3-1/2 hours for each.

How much does the CSLB Plumbing (C-36) Trade Examination cost?

$450 — Original application (exam or waiver, one classification) (CSLB, one-time); $51.43 — Examination registration (each registration, first attempt or retake) (PSI Services LLC, per attempt); $200 — Initial license fee (sole owner) (CSLB, one-time); $350 — Initial license fee (non-sole owner: partnership, corporation, LLC, joint venture) (CSLB, one-time). Two payees: application and license fees go to CSLB, the per-exam registration fee to PSI. CSLB's 2023 “Get Licensed to Build” PDF still names a $100 rescheduling fee; it appears neither on CSLB's current fee list nor in Business and Professions Code § 7137 as amended effective 1 January 2026, so it is not stated here. The application fee is charged once per original license application and covers both required exams.

What languages is the CSLB Plumbing (C-36) Trade Examination offered in?

English · Spanish. CSLB publishes Spanish versions of 10 exams and names this one among them. Candidates requesting a translator for those exams are required to take the Spanish version instead.

Is the CSLB Trade — Plumbing (C-36) study guide a PDF?

Yes. CSLB Class C-36 Plumbing — Trade Exam Study Guide (2026) downloads as PDF + EPUB (290 pages, 200 practice questions inside), $14.99 one-time, and the files are yours to keep. The 360 practice questions on this page stay free without it. See the study guide →

Practice questions are AI-assisted study material written from California Contractors State License Board (CSLB) and reviewed by PrepPass — for practice only, not official exam questions. Bank updated August 2026. PrepPass is an independent study resource and is not affiliated with, endorsed by, or approved by California Contractors State License Board (CSLB). Always confirm current exam details with California Contractors State License Board (CSLB).
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