CSLB trade exam · C-36 – Plumbing

Pass the California Plumbing (C-36) contractor exam.

Original practice questions weighted like the official CSLB outline, each with a plain-language explanation and the code or source behind the answer. In English and Spanish.

25 questions. No sign-up. A score for each of the 5 exam sections.

A first C-36 license takes two exams

The C-36 exam tests your trade; Law & Business is the same exam for every classification. You have 18 months from the day CSLB accepts your application to pass both. Already licensed and adding C-36? You take only the C-36 exam.

Exam 1 · every license

Law & Business

Contracts, employment, business finances, safety, licensing, liens and public works.

  • 7 sections
  • About 115 questions
  • 3½ hours
Exam 2 · your trade

C-36 – Plumbing

The trade exam for the C-36 Plumbing license: planning and estimating, underground and rough systems, finish plumbing installations, service, repair and remodel of plumbing systems, and safety.

  • 5 sections
  • 3½ hours

What the C-36 exam covers

CSLB's study guide splits the Plumbing exam into 5 sections. We weight practice the same way, so each section gets the share of your time it has on the exam.

  • Closed book: no reference materials in the room
  • Multiple choice, four answers, one best answer
  • 3½ hours to finish, as for every CSLB exam
  • CSLB does not publish the number of questions
  • Offered by CSLB in English and Spanish
Check your level per section
Planning and Estimating22%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.
Underground and Rough Systems22%Excavation and underground installations; piping layout and installation; fuel gas piping; insulation and system testing.
Finish Plumbing Installations20%Plumbing fixtures and appliances; water heaters; shut-off valves; specialty installations; industrial and commercial piping and sanitary systems.
Service, Repair, and Remodel Plumbing Systems19%Troubleshooting plumbing issues; isolating leaks and damage; repairing plumbing; retrofitting plumbing; disposal of plumbing materials.
Safety17%Personnel safety; job site safety; environmental safety.

CSLB License Examination Study Guide, Plumbing (C-36), form 13E-36 (03-2026), for examinations scheduled on or after March 1, 2025. CSLB notes that the percentages are approximate.

References CSLB lists for this exam

  • 2025 California Building Code (California Code of Regulations, Title 24)
  • 2025 California Green Building Standards Code (CALGreen; Title 24)
  • 2025 California Mechanical Code (Title 24)
  • 2025 California Plumbing Code (Title 24)
  • California Manual on Uniform Traffic Control Devices, 2014 Edition, Revision 8 (Caltrans)
  • Cal/OSHA General Industry, Construction and Electrical Safety Orders, 2024 (California Code of Regulations, Title 8)
  • Underground Service Alert Guidelines (California Government Code 4216 and Business and Professions Code 7110)

Time and format: CSLB Examination FAQ.

How we get you ready for it

1,142 practice questions across the 5 official sections, plus 300 flashcards, in English and Spanish.

Practice one section at a time

All 5 sections, each with its share of the exam next to it. Put your hours where they change your score.

Every answer shows its source

A plain-language explanation and the code section or reference it comes from, so you learn the rule, not just the letter.

Every mistake comes back to you

Questions you got wrong collect in one place and wait to be fixed, and each round starts with what you have not seen yet.

Full-length practice exams and a readiness score

About 115 questions against the official 3½-hour clock, weighted like the outline, and a clear signal for when you are ready to book. CSLB does not publish the exact number of questions.

Study on your phone between jobs, in English or Spanish, and install it on your home screen. Everything a pass includes.

Pay once: Plumbing alone or with Law & Business

One payment, no subscription, no auto-renewal. Access opens the moment the payment clears.

Three months of full access: enough for most people to prepare and sit the exam.

Six months of access plus three study extras, listed on each card.

One exam

Plumbing

Passed Law & Business already, or adding C-36 to your license

$79$109 one time

  • 1,142 questions, each with its source
  • All 5 official sections, weighted like the CSLB outline
  • 300 flashcards and timed practice exams

180 days adds

  • Study plan built from your exam date
  • Key numbers sheet: the figures of the C-36 exam, each with its source
  • Search across the question bank
  • 6 months of access, room for a retake

Only need Law & Business? It is $79 on its own. Refunds: full refund within 14 days if you have used no more than 50 questions and not started a timed mock exam. See our Refund Policy.

Pass guarantee on every exam: if you study with us and don't pass, we extend your access for free until your next attempt. The first 30 days take one click in your dashboard — no paperwork. How it works.

Questions about the C-36 exam

Something else? Email support@cacontractorexam.com and we reply within 2 business days.

Do I also need the Law & Business exam?

For a first license, almost certainly. CSLB requires the Law and Business exam from almost every applicant in addition to the trade exam, and you have 18 months from the day your application is accepted to pass both. Already licensed and adding C-36 to your license? Then you take only the trade exam. How the whole process works.

What does a C-36 – Plumbing license let me do?

A plumbing contractor provides a means for a supply of safe water, ample in volume and of suitable temperature for the purpose intended and the proper disposal of fluid waste from the premises in all structures and fixed works. Source: 16 CCR §832.36.

What is the format of the C-36 exam?

A closed-book, computer-based, multiple-choice exam at a PSI test center, with four choices per question and one best answer. There is no penalty for guessing, so answer every question. CSLB gives 3½ hours for each exam and does not publish how many questions the C-36 exam has.

Can I take the C-36 exam in Spanish?

Yes. C-36 – Plumbing is one of the CSLB exams offered in Spanish. Our practice material is in both languages, and you can switch whenever you like. Taking the exams in Spanish.

What if I fail?

You can retake it after 21 calendar days, as long as you are inside your 18 months. If you studied with us, our pass guarantee extends your access for free until your next attempt. What happens after a fail.

Are these the real exam questions?

No. CSLB does not release its questions, and anyone claiming to sell them should be avoided. Our questions are original, written from the official outline and the codes and references CSLB lists for the exam.

Guides for C-36

How ready are you for the C-36 exam?

25 questions across the 5 sections, about 20 minutes, no sign-up.