- You need 45 correct answers out of 60 scored questions - exactly 75% - to pass the C-15 trade exam.
- You get 120 minutes, and PSI may slip in 1-10 unscored experimental questions you can't identify.
- Steep Roofing is the single largest domain at 16 of 60 questions - nearly a quarter of your score.
- Only the listed 2018 International Building Code may be opened during testing; everything else is study-only beforehand.
The Passing Score, Exactly
If you're preparing for the Nevada C-15 Roofing and Siding Contractor Trade Exam, the number that matters most is simple: 45 correct answers out of 60 scored questions, or 75%. That's the passing threshold set for the full trade exam administered by PSI on behalf of the Nevada State Contractors Board. There's no partial credit, no curve, and no rounding up from 44. Miss the mark by one question and you're scheduling a retake.
This is worth stating plainly because a lot of exam confusion online blends the full C-15 trade exam with the narrower C-15a Roofing exam, or with unrelated credentials that happen to share the "C-15" label. This article is strictly about the Nevada C-15 Roofing and Siding Contractor Trade Exam covering all nine domains - not a subset, not a different jurisdiction's version.
How PSI Scores the C-15 Trade Exam
The exam blueprint, per the PSI candidate bulletin dated March 25, 2026, lays out 60 scored questions delivered by computer in multiple-choice format, with 120 minutes on the clock. PSI is also permitted to insert between 1 and 10 unscored experimental questions into the same test session and the same time window. These pretest items look identical to scored questions - there's no flag, no separate section, no way to tell which ones count.
Practically, this means two things for your test-day strategy:
- Don't try to "outsmart" the exam by guessing which questions are experimental. You can't reliably tell, and second-guessing wastes time.
- Pace against 120 minutes, not against 60 questions. Since the actual question count on screen could be higher than 60 due to unscored items, budget your time based on the clock, not a fixed per-question average.
For a broader breakdown of how the exam is structured and delivered, the NV-C15 Study Guide 2026 walks through pacing strategy in more depth. If you're still deciding whether this exam matches your background, NV-C15 Requirements 2026 covers the four-year experience threshold and education substitutions before you even sit for it.
Why Steep Roofing Carries the Most Weight
Passing score conversations tend to focus only on the raw number, but 45/60 doesn't mean each domain matters equally. The nine content areas on the blueprint are weighted unevenly, and one domain dwarfs the rest:
Steep Roofing - 16 of 60 Questions
This is the largest single domain on the exam, worth more than a quarter of your scored questions. Candidates who under-prepare here put their entire passing margin at risk.
- Shingle, tile, and slate installation practices
- Underlayment selection and application in steep-slope assemblies
- Fastening patterns, exposure, and weather-related installation limits
The remaining eight domains - Safety, Roofing Substrates, Roofing Repairs, Elastomeric Roofing, Built-up Bituminous Roofing, Sheet Metal and Flashing, Siding, and Photovoltaic Systems - split the balance of the 60 questions. Because Steep Roofing alone is worth as much as several smaller domains combined, it's the single highest-leverage area to master before test day.
For a question-by-question sense of how each of the nine domains is likely to be distributed and what each one actually tests, see the NV-C15 Exam Domains 2026 guide. It's the natural companion to this passing-score breakdown - knowing the number you need is only half the equation; knowing where those points come from is the other half.
Key Takeaway
Treat Steep Roofing as your anchor domain. If your working knowledge of shingle, tile, or slate systems is shaky, close that gap before spending extra hours on smaller domains like Photovoltaic Systems or Elastomeric Roofing.
Question Format and What "Open Book" Really Means
The C-15 trade exam is computer-delivered and entirely multiple-choice - there's no written-response or scenario-simulation component. What trips up candidates isn't the format, though; it's the reference rules.
Only the listed 2018 International Building Code may be opened during the actual exam session. Everything else on the standard study list - NRCA manuals, OSHA materials, and other referenced publications - is for preparation only and cannot be brought into the testing room. That distinction matters because candidates sometimes assume "open book" means every manual they studied from is available at the terminal. It isn't.
Reference handling rules are specific:
- Highlighting, underlining, and permanent tabs placed in the code book before the exam are allowed.
- Handwritten notes - whether added before testing or scribbled during the exam - are prohibited.
- Loose papers, sticky notes, or inserted pages are not permitted.
- A silent, nonprinting, nonprogrammable calculator is allowed at the workstation.
If you're wondering how this level of detail translates into overall exam difficulty, How Hard Is the NV-C15 Exam? breaks down the difficulty picture domain by domain. And if you want to see how other candidates have historically approached the pass/fail line, NV-C15 Pass Rate 2026 lays out what the available data actually shows.
Registration, Fees, and Retake Rules
The passing score itself is fixed, but the path to your seat - and to a retake if you need one - has its own mechanics worth knowing before you schedule.
| Item | Detail |
|---|---|
| Trade exam only | $95 |
| Trade exam + Contractor Management Survey (CMS) | $140 combined |
| Retake fee | Same fee schedule as initial attempt |
| Retake wait period | Two weeks minimum |
| Attempt limit | Three failures void the application |
| Scheduling window | Required exams must be completed within six months of application submission |
Board approval must happen before you can schedule a test date - you can't simply register with PSI on your own timeline. This scheduling structure, plus the six-month completion window, is why candidates who fail on their first attempt shouldn't treat a retake casually. Two failed attempts already puts you one miss away from a voided application, so the two-week retake gap should be used deliberately, not just waited out.
These fees are separate from the broader licensing costs - application fee, initial licensing, biennial renewal, and Residential Recovery Fund charges - which are detailed in NV-C15 Certification Cost 2026. It's a useful companion read if you're budgeting for the full path to licensure rather than just the exam sitting.
Key Takeaway
Because three failures void your application entirely, the smartest move after a first fail is a focused review of your weakest domain - likely Steep Roofing given its 16-question weight - rather than a blanket re-study of everything.
Turning 45/60 Into a Realistic Target
Once you know the number - 45 correct out of 60 - the more useful question becomes: which domains should absorb your limited study hours? A simple, disciplined allocation approach based on the blueprint weighting works better than treating all nine domains equally.
Steep Roofing + Safety
- Work through shingle, tile, and slate installation standards in depth - this is your highest-point domain
- Layer in Safety fundamentals since job-site hazard awareness threads through nearly every roofing scenario question
Roofing Substrates + Roofing Repairs
- Study substrate compatibility and preparation before covering common failure and repair scenarios
- Tab your 2018 IBC sections relevant to substrate and repair code requirements
Built-up Bituminous, Elastomeric Roofing, Sheet Metal and Flashing
- Group these together since flashing details intersect with both bituminous and elastomeric systems
- Practice reading flashing and metal detail questions carefully - precision language matters here
Siding, Photovoltaic Systems, Full Review
- Cover Siding attachment and material standards, then Photovoltaic System basics for roof-mounted installations
- Run a full-length timed practice pass under 120-minute conditions to check pacing
This kind of weighted scheduling only works if you know the domain breakdown cold - which is exactly what the NV-C15 Exam Domains 2026 guide maps out in full. Pair that with hands-on timed practice at our practice test platform so the 120-minute pacing becomes second nature before test day rather than something you discover mid-exam.
For a fast pre-exam refresher once you've done the deeper study, the NV-C15 Cheat Sheet 2026 condenses the must-know facts - including the passing score itself - onto a single page you can review the night before.
Before you lock in a test date, double-check the current scheduling windows and any bulletin updates - testing logistics can shift between bulletin revisions, and NV-C15 Exam Dates 2026 tracks those specifics separately from this passing-score breakdown. And if any of the terminology here - CMS portions, trade qualifier, Board approval - still feels unfamiliar, start with What Is NV-C15? or NV-C15 Meaning for the foundational definitions before diving back into scoring mechanics.
FAQ
You need 45 correct answers out of 60 scored questions, which equals 75%. This is the fixed passing threshold for the full C-15 Roofing and Siding Contractor trade exam administered by PSI.
No. PSI may include 1-10 unscored experimental questions within the same 120-minute session, but they are not counted toward your 45-out-of-60 result. You cannot identify which questions are experimental, so answer every question with equal care.
Steep Roofing, which accounts for 16 of the 60 scored questions - the largest single domain on the blueprint. Weakness there has an outsized effect on whether you clear the 45-question threshold.
No. Handwritten notes and added papers are prohibited both before and during testing. You may pre-highlight, underline, and add permanent tabs to your 2018 International Building Code reference, but no loose notes are allowed.
Retakes require a two-week waiting period and follow the standard fee schedule ($95 for the trade exam alone, or $140 combined with the CMS portion). Three total failures void the application entirely, so a careful, domain-focused review between attempts matters.