Free Practice Questions for CA C-36 Plumbing
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Key Facts: CA C-36 Plumbing Exam
C-36
Contractor Classification
CSLB C-36 classification
3.5 hours
Time Allowance
CSLB examination FAQ
Closed-book
Test Format
CSLB C-36 study guide
$51.43
PSI Exam Registration
PSI C-36 candidate guide; application and license fees separate
At test site
Passing Percentage
CSLB studying for the examination
California C-36 is a plumbing contractor examination. It is closed-book, uses four-choice multiple-choice questions, and allows 3.5 hours. CSLB provides the required passing percentage at the test site; the cited candidate guides do not publish an exact question count.
Sample CA C-36 Plumbing Practice Questions
Try these sample questions to review concepts for the CA C-36 Plumbing exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 163+ question experience with AI tutoring.
1Under 2025 California Plumbing Code (CPC) Table 702.1, what is the minimum trap and drain pipe size required for a water closet?
2Under 2025 CPC Section 708.1, when a 1/4-inch-per-foot slope is impracticable due to street sewer depth or structural features and the Authority Having Jurisdiction approves a reduced grade, what is the minimum allowable slope for a 4-inch horizontal drainage pipe?
3Under 2025 CPC Table 702.1, what is the drainage fixture unit (DFU) value assigned to a private residential lavatory?
4Per the CPC as adopted in California, what is the minimum depth of a fixture trap seal?
5According to 2025 CPC Sections 707.4 and 719.1, at what maximum horizontal interval must cleanouts be installed on straight runs of horizontal drainage piping?
6Using 2025 CPC Table 702.1, a commercial restroom group contains four public 1.28 GPF water closets (4 DFU each), two public lavatories (1 DFU each), and one floor drain (2 DFU). What is the total connected DFU load?
7Per 2025 CPC Section 708.1, what is the minimum uniform slope required for a 2-inch horizontal drainage pipe?
8A horizontal building drain at 1/4 inch per foot serves seven private 1.28-gpf water closets and no other fixtures. The load is 21 DFU. Under 2025 CPC Table 703.2, what is the smallest listed pipe size that satisfies both the DFU capacity and the water-closet count limit?
9Under 2025 CPC 1001.1, what is the maximum vertical distance from a fixture outlet to the trap weir?
10When calculating sanitary branch loads from 2025 CPC Table 702.1, how many drainage fixture units (DFU) does a residential bathtub with an overhead combination shower represent?
About the CA C-36 Plumbing Exam
The C-36 Plumbing examination is the trade examination for California plumbing contractor applicants. CSLB develops the examination and PSI administers it in person. It assesses the planning, installation, repair, and safety knowledge needed by a plumbing contractor. Original applicants generally also take the separate Law and Business examination, subject to CSLB waiver rules.
Exam sponsor: Contractors State License Board (CSLB). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.
Assessment
Closed-book computer-based multiple choice; four answer choices per question; calculator provided
Time Limit
3.5 hours
Passing Score
Required correct-answer percentage disclosed at the test site
Exam / Certification Fees
$51.43 per C-36 exam registration (PSI); CSLB application and license fees are separate
Exam sponsor websiteFees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.
Official sources
- CSLB C-36 Plumbing Contractor classification · Source checked 2026-10-30
- CSLB C-36 examination study guide · Source checked 2026-10-30Effective for examinations scheduled on or after March 1, 2025; resource list revised March 2026 includes the 2025 California Plumbing Code
- PSI C-36 Licensing Examination Information Guide · Source checked 2026-10-30Current English fee table lists $51.43 per registration
- CSLB examination FAQ · Source checked 2026-10-30
- CSLB studying for the examination · Source checked 2026-10-30
- CSLB qualifying experience and education credit · Source checked 2026-10-30
- CSLB Certification of Work Experience · Source checked 2026-10-30
- CSLB application instructions · Source checked 2026-10-30
- CSLB fee schedule · Source checked 2026-10-30
- CSLB license issuance requirements · Source checked 2026-10-30
- CSLB licensing triggers and limited minor-work exemption · Source checked 2026-10-30Permit requirement, employee labor and total project cost are separate licensing triggers; the limited under-$1,000 exemption cannot be created by splitting a larger project.
Our practice resources: topics covered
We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.
Planning and Estimating
Project scope, compliance, pipe and vent sizing, plan interpretation, inspections, conservation, coordination, and job costing
Underground and Rough Systems
Excavation, underground work, piping installation and layout, fuel gas systems, insulation, and testing
Finish Plumbing Installations
Fixtures, appliances, water heaters, valves, specialty work, and commercial or industrial piping and sanitary systems
Service, Repair, and Remodel Plumbing Systems
Diagnosing faults, finding damage and leaks, repairs, retrofits, and disposal of removed materials
Safety
Protection of workers, safe job sites, and environmental precautions; CSLB describes blueprint weights as approximate
Preparing for the CA C-36 Plumbing Exam
What You Need to Know
- Passing score: Required correct-answer percentage disclosed at the test site
- Assessment: Closed-book computer-based multiple choice; four answer choices per question; calculator provided
- Time limit: 3.5 hours
- Exam / certification fees: $51.43 per C-36 exam registration (PSI); CSLB application and license fees are separate Official sources
Using Our Practice Resources
- Work through all 163 available questions
- Review every answer and explanation
- Track weak areas and revisit them
- Use our AI tutor for tough concepts
CA C-36 Plumbing: Suggested Study Strategy
Frequently Asked Questions
Which California plumbing credential does this page cover?
It covers the CSLB C-36 Plumbing Contractor trade examination. Journey-level plumbing experience is part of qualifying for a contractor license; it is not the name of this examination.
How many questions are on the C-36 examination, and what score passes?
The cited CSLB and PSI candidate guides do not publish an exact official question count. CSLB gives the required passing percentage at the test site, and the time allowance is 3.5 hours. The 163 independent practice questions on this page are study inventory, not the length of the real examination.
Can I bring a code book or calculator?
The C-36 examination is closed-book and reference materials are prohibited. A calculator is provided for questions requiring calculations.
Which code edition is listed in the official study guide?
The CSLB C-36 guide revised in March 2026 lists the 2025 California Plumbing Code among its suggested references. It also lists other California construction codes and safety resources. Use the current official guide when selecting study materials.
What experience and education are required?
The qualifying individual must be at least 18 and document four years of qualifying experience in the classification within the last 10 years. No formal education is required. CSLB may credit up to three years of qualifying education or training, with at least one year of practical experience.
What fees are separate from the examination fee?
PSI lists $51.43 per examination registration. CSLB charges a separate $450 original application processing fee and an initial license fee of $200 for a sole owner or $350 for a non-sole owner. Fingerprinting, bond premiums, insurance, and study materials can add costs.
What happens if I fail the examination?
A retake requires a 21-calendar-day wait and another $51.43 PSI registration. Required examinations must be passed before the application’s 18-month void date. CSLB counts the period from acceptance (posting); use the date in your notice. After expiry, a new application and fees are required.
Does a small plumbing job avoid the contractor-license requirement?
The limited minor-work exemption requires no building permit, no employee labor, and combined labor, materials and other project costs below $1,000. A larger project cannot be divided to claim the exemption, and an unlicensed person must not advertise as licensed. This licensing exemption is separate from an examination waiver.