The Roofing (C-39) Exam: Format, Topics, and Passing Score
The Roofing (C-39) exam is a closed-book, computer-based multiple-choice test with four choices per question. CSLB gives 3.5 hours for each exam, but it does not publish a universal question count or fixed public passing percentage. The official guide for exams scheduled on or after January 1, 2023 gives the current topic weights, including the large steep-slope and safety sections.
The C-39 exam at a glance
| Detail | What you can verify |
|---|---|
| Format | Closed-book, multiple choice, four choices per question (CSLB C-39 study guide) |
| Time | 3-1/2 hours for each examination (CSLB exam FAQ) |
| Location | In person at a PSI test center; trade exams are completed in California or Oregon (CSLB exam FAQ) |
| Question count | CSLB does not publish a universal count in the sources above |
| Passing score | CSLB tells you the percentage needed at the test site; it does not publish one fixed public percentage (CSLB studying) |
| Retake timing | Wait 21 calendar days after an attempt; a fee is required for each registration (PSI bulletin) |
| Exam fee | $51.43 per registration in the current PSI bulletin (PSI) |
The official guide says a calculator will be provided for questions that require mathematical computation and that there is no penalty for guessing. Read every option before choosing the best answer, particularly when two answers look like familiar roofing terms but only one fits the sequence or roof system.
The five C-39 topic areas
The official Roofing guide divides the exam into five approximate sections:
| Section | Approximate weight | What to study |
|---|---|---|
| Planning and Estimating | 22% | Planning and estimating roof projects |
| Job Site Preparation | 13% | Protecting surroundings, correcting problems, tearing off existing roofing |
| Low-Slope Roof Projects | 17% | Flashings, ventilation, underlayment, low-slope systems, repairs |
| Steep-Slope Roof Projects | 26% | Flashings, ventilation, underlayment, steep-slope systems, repairs |
| Safety | 22% | Personnel safety, job-site safety, fall protection |
Steep-slope work is the largest single section, while safety is tied with planning and estimating. That gives you a decision rule: study the largest sections first, but give safety its own review block because it reaches across every roof job.
A practical two-week study plan
- Days 1–2: make the map. Read the official C-39 guide and the trade classification page. Mark each area familiar, rusty, or unknown.
- Days 3–5: plan and prepare. Study estimating, job-site protection, corrections, and tear-off sequence. Write the reason behind each step.
- Days 6–9: split roof systems. Give separate sessions to low-slope and steep-slope systems. Organize flashings, ventilation, underlayment, installation, and repair by system rather than by a random product list.
- Days 10–11: make safety concrete. Review personnel safety, job-site controls, and fall protection. Ask what hazard the rule controls and when it applies.
- Days 12–14: simulate and repair. Take timed practice sets, review every miss, and repeat weak sections until you are consistently scoring 85% or better in practice.
The weights are a triage tool, not a promise about the next exam form. Check the guide's issue date before studying and use the classification page to keep your scope vocabulary aligned with the C-39 license.
Worked example: reason from roof area
A rectangular roof plane measures 18 feet by 42 feet. What is its area before adding waste or the area of other roof planes?
- A. 60 square feet
- B. 378 square feet
- C. 756 square feet
- D. 1,512 square feet
Correct answer: C. 756 square feet. Multiply the two plan dimensions: 18 × 42 = 756 square feet. The exam skill is separating the base area calculation from later adjustments for slope, laps, waste, or additional planes. Read the question for the unit it actually asks for before changing the number.
This is an original study example, not a CSLB exam question. CSLB questions are confidential.
How to practice for the C-39 exam
Start with the free CSLB C-39 study guide, then use the Peerless Roofing (C-39) Study Guide Book to learn the systems and job sequences. Pair the book with the CSLB Law and Business exam guide because the qualifying process normally includes Law and Business as well as the trade exam.
Use practice sets to expose weak topics, not to collect a flattering score. After each set, label the miss as a vocabulary problem, a sequence problem, a calculation problem, or a safety judgment. That label tells you what to review next.
FAQ
How many questions are on the C-39 exam?
CSLB does not publish a universal question count in the current C-39 study guide or exam FAQ. The official information is the format: closed book, multiple choice with four choices, and a calculator provided for mathematical questions. Use the published topic weights and timed practice rather than an unverified question total.
What is the C-39 passing score?
CSLB does not publish one fixed public percentage for the Roofing exam. Its studying guidance says the required percentage is provided at the test site, and the passing report does not show the overall score. A practice target of 85% or better is a preparation benchmark, not CSLB's official cutoff.
Can I take the Roofing exam online?
No. CSLB says qualifying exams are taken in person at PSI locations. Trade exams must be completed in California or Oregon. Wait for CSLB to refer your accepted application for testing, then use PSI to confirm the current appointment, location, and payment details.
How soon can I retake the C-39 exam?
The PSI bulletin says candidates may retake an examination after 21 calendar days, provided the application is still valid, and must pay the exam fee for each registration. Use that interval to review the section that produced the most errors and then practice the same skill under time pressure.
Sources
- CSLB: Roofing (C-39) study guide
- CSLB: C-39 classification
- CSLB: Examination FAQ
- CSLB: Studying for the Examination
- PSI: California contractor examination bulletin
Peerless Institute has helped California contractors prepare for CSLB exams since 1953. Use the Peerless Roofing (C-39) Study Guide Book for system review, then pair it with the CSLB Law and Business exam guide for the other required exam area.