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California · Updated October 2026

California CSLB Class B General Building Trade Exam: free practice test

The trade exam for California's most popular license class. It tests building practice, framing and structural work, finish trades, safety and estimating, all from memory.

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About the CSLB Class B exam

The trade exam for California's most popular license class. It tests building practice, framing and structural work, finish trades, safety and estimating, all from memory.

What's on the exam

CSLB Class B
License Scope and Planning
7 key facts
Estimating and Takeoffs
7 key facts
Site Work and Foundations
7 key facts
Concrete and Moisture Control
6 key facts
Framing and Structural
7 key facts
Stairs, Guards and Egress
7 key facts
Core Trades Coordination
7 key facts
Fire Safety and Finishes
6 key facts
Jobsite Safety (Cal/OSHA)
7 key facts

Each branch is a topic in the official outline. Members see every key fact on the full mind map. Read the free study guide →

How to pass the CSLB Class B exam

  • The B license requires work involving at least two unrelated trades (framing and carpentry don't count). Expect scope-of-license questions.
  • Learn residential code numbers by heart: stairs, guards, egress, anchor bolts, fireblocking.
  • Practice board-foot and concrete math without a reference book.

Save your results and get your Readiness Score

Create a free account after the test: your score by topic, a mistakes bank, the first study-notes topic, flashcards and the Construction Math Formula Sheet.

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What's in the full CSLB Class B prep

Full question bank

600+ exam-style questions written to each official outline. Every answer explained, with the rule it comes from.

Timed exam simulator

Real question counts and time limits, so test day feels like practice day.

Exam Readiness Score

One 0 to 100 number that tells you when you're ready to book. Reach 80 and you're covered by our Pass Guarantee.

Flashcards + spaced repetition

530+ cards that come back right before you'd forget them. Five minutes a day keeps every number fresh.

Key study notes

Each topic boiled down to the 5 to 7 facts that get tested, with the statute or code section.

Mind maps

See the whole exam on one screen: every topic and the facts under it.

Sample questions with answers

These are the questions in the free test above, with answers. Try the test first. You'll learn more by getting some wrong.

1. A Class B General Building contractor may take a prime contract for a project that involves:
Answer: At least two unrelated building trades or crafts. B&P §7057: a B contractor may prime a contract involving at least two unrelated trades, other than framing or carpentry. Fire protection and well drilling require their own licenses.
2. The B-2 Residential Remodeling classification covers residential improvement projects that involve at least:
Answer: Three unrelated trades. The B-2 (created in 2020) is for residential remodeling involving at least three unrelated building trades, without structural changes to load-bearing parts.
3. Under the residential code, sill-plate anchor bolts must be at least 1/2 inch diameter, embedded at least 7 inches into concrete, and spaced no more than:
Answer: 6 feet on center. CRC/IRC R403.1.6: max 6 feet on center, with a bolt within 12 inches of each end of each plate section.
4. The maximum riser height for a stairway in a one- or two-family dwelling under the California Residential Code is:
Answer: 7-3/4 inches. CRC/IRC R311.7.5.1: 7-3/4 inches maximum riser, with a 10-inch minimum tread depth.
5. Residential handrail height, measured vertically from the tread nosing, must be:
Answer: 34 to 38 inches. CRC/IRC R311.7.8.1 requires handrails between 34 and 38 inches above the nosing.
6. In a dwelling, guards are required where a walking surface is more than how far above the floor or grade below?
Answer: 30 inches. R312.1.1: guards are required where the surface is more than 30 inches above the floor or grade within 36 inches horizontally.
7. An emergency escape and rescue opening above grade floor must have a minimum net clear opening of:
Answer: 5.7 sq ft. R310: 5.7 sq ft (5.0 sq ft at grade floor), minimum 24 in high and 20 in wide, with a sill no higher than 44 inches.
8. In concealed wall spaces of stud walls, fireblocking is required vertically at ceiling and floor levels and horizontally at intervals not exceeding:
Answer: 10 feet. R302.11: fireblocking at ceiling and floor levels and at 10-foot horizontal intervals.
9. Fire-rated gypsum board used for rated assemblies is typically:
Answer: 5/8-inch Type X. 5/8-inch Type X has glass fibers in the core for fire resistance and is the standard for rated walls and garage separations under living space.
10. How many board feet are in one 2 × 12 that is 16 feet long?
Answer: 32 BF. Board feet = thickness (in) × width (in) × length (ft) ÷ 12 = 2 × 12 × 16 ÷ 12 = 32 BF.
11. Adding more water to a concrete mix (raising the water-cement ratio) will:
Answer: Decrease strength and durability. Higher water-cement ratios make concrete easier to place but lower its strength and durability.
12. Hold-down hardware at the ends of a shear wall primarily resists:
Answer: Uplift and overturning. Hold-downs tie the end posts to the foundation to resist overturning uplift. Anchor bolts and sill nailing resist sliding.
13. The minimum thickness of a residential concrete floor slab on ground is:
Answer: 3-1/2 inches. R506.1 sets a 3-1/2-inch minimum thickness for concrete slab-on-ground floors.
14. A vapor retarder placed under a residential slab on grade is typically:
Answer: 6-mil polyethylene. R506.2.3 calls for a 6-mil (0.006 inch) polyethylene or approved vapor retarder with lapped joints.
15. A straight or extension ladder should be set so that the base is out from the wall by about:
Answer: 1/4 of the working length. The 4-to-1 rule: 1 foot out for every 4 feet of working length (about a 75-degree angle).

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  • Spaced repetition + mistakes bank
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  • Video lessons as they release
  • New exams added during your access
  • 5 bonuses: formula sheet, tabbing guide, study planner and more
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Question Bank$49

Every practice question for one exam, with explanations, your mistakes bank and reports.

  • Every question (50), every answer explained
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Exam Simulator$39

Full-length timed simulations with real question counts and time limits.

  • Full-length timed simulations
  • Real question counts and time limits
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Every study-notes topic, every flashcard with spaced repetition, and the full mind map.

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Licensing guide

How to Get a Contractor License in California (2026): To get a California contractor license, you need at least four years of journey-level experience in the last 10 years, a $450 application to the Contractors State License Board (CSLB), and passing scores on the Law and Business exam plus a trade exam for most classifications. After you pass, you pay a $200 or $350 initial license fee, file a $25,000 contractor bond, and file workers' compensation coverage or an exemption. You need a license for any job of $1,000 or more in labor and materials, or any job that needs a building permit.

Related practice tests

Exam details are summarized from the official candidate information available in October 2026. Boards change formats and fees, so confirm with Contractors State License Board (CSLB) before you book. ContractorConquer is not affiliated with any licensing board or testing company.

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