During hot-weather concreting at 95 degrees F with dry wind, the MOST important immediate practice to prevent surface defects is to:

Protect the surface from moisture loss with fogging, evaporation retarder, or prompt curing

Use a higher-slump mix and delay finishing

Add extra retarder and leave it exposed

Increase the mix water to keep it workable

The MOST reliable method to prevent backflow contamination of the potable water supply at a fixture is:

Providing a physical air gap of adequate height above the fixture flood rim

Increasing the supply water pressure

Installing a single check valve

Adding length to the supply pipe

Under CALGreen, composite wood used in interior casework, such as particleboard cabinet boxes, must meet formaldehyde emission limits. This requirement is set MAINLY to:

Protect indoor air quality and occupant health

Increase the strength of the cabinets

A weep screed at the base of a stucco wall must be located at least how far above adjacent surfaces?

At least 4 inches above earth or 2 inches above paved areas

At least 8 inches above paved areas

When applying an oil-based stain and clear topcoat to interior wood trim, why should oily rags be spread out or placed in a sealed metal container after use?

Because they can spontaneously combust as the oil oxidizes and generates heat

To speed the drying of the topcoat

To prevent the stain color from fading

A straight (non-self-supporting) ladder is set up against a wall. What placement BEST follows the recommended angle for safe use?

Base 1 foot out for every 4 feet of working height

Any angle is fine if the top is tied off

Base 4 feet out for every 1 foot of working height

Base directly against the wall, nearly vertical

CSLB General Building (B) Trade Practice Test

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CSLB General Building (B) Trade Examination — Exam facts
Administering body	Contractors State License Board (CSLB), California Department of Consumer Affairs — exam delivered by PSI Services LLC Source: CSLB — Examinations Frequently Asked Questions
Questions	Not published by CSLB What we read and found nothing in: CSLB — Step 7: Studying for the Examination
Time limit	210 minutes Source: CSLB — Examinations Frequently Asked Questions
Passing score	Not published by CSLB What we read and found nothing in: CSLB — Step 7: Studying for the Examination
Fees	$450 — Original application (exam or waiver, one classification) (CSLB, one-time) $51.43 — Examination registration (each registration, first attempt or retake) (PSI Services LLC, per attempt) $200 — Initial license fee (sole owner) (CSLB, one-time) $350 — Initial license fee (non-sole owner: partnership, corporation, LLC, joint venture) (CSLB, one-time) Source: CSLB — List of All CSLB Fees
Languages offered	English · Spanish Source: CSLB — Examinations Frequently Asked Questions

Exam facts, with a source for every line

Frequently asked questions

How many CSLB General Building (B) trade questions are here?+

700 original practice questions across the 5 official content areas of the B trade exam — Core Trades, Framing & Structural, Finish Trades, Planning & Estimating, and Safety — weighted the way the real exam is, with 2025 California code references.

Is the B trade exam separate from the Law & Business exam?+

Yes. To get a Class B contractor license you must pass BOTH: the Law & Business exam AND this General Building (B) trade exam. They are two separate exams, each about 3.5 hours at a PSI testing center.

How many questions is the real B exam, and what's the passing score?+

CSLB does not publish the exact question count or passing score for the trade exams. You are told the passing mark at the test site. The exam is about 3.5 hours, closed-book, with a calculator provided for the math questions.

Are these the real CSLB exam questions?+

No. Every question is 100% original, written from public-domain sources (the 2025 California Building, Residential, Electrical, Plumbing, Mechanical and Energy Codes, CALGreen, and Cal/OSHA Title 8). We never copy real exam questions or paid prep material.

Can I take the B exam in Spanish or Chinese?+

The official B trade exam is offered in English and Spanish. Other languages may be available by translator request through CSLB (allow a few weeks). PrepPass practice is in English, 中文, and Español — and you can switch the question language to English to rehearse the wording you'll see at the test center.

Does the B exam have math questions?+

Yes — expect calculation questions on concrete cubic yards, board feet, rafter and stair geometry, roofing squares, excavation volumes, and cost/estimating takeoffs. A calculator is provided. Our bank includes plenty of practice math.

Sample practice questions

A few real questions from this free bank, with full explanations. Use the practice tool above for the whole set.

1. Core Trades
A concrete mix is batched with 620 pounds of cement per cubic yard. To hold the water-cement (w/c) ratio at a MAXIMUM of 0.45, what is the greatest amount of water that may be used per cubic yard?
- a.About 279 pounds
- b.About 344 pounds
- c.About 248 pounds
- d.About 310 pounds
Answer: a
Explanation: The w/c ratio is water weight divided by cement weight, so maximum water = 0.45 x 620 = 279 lb. 248 lb corresponds to a 0.40 ratio, 310 lb to 0.50, and 344 lb to 0.55, all of which miss the specified 0.45 limit.
Source: 2025 CA Building Code (CBC) Chapter 19 (Concrete)
2. Core Trades
During hot-weather concreting at 95 degrees F with dry wind, the MOST important immediate practice to prevent surface defects is to:
- a.Protect the surface from moisture loss with fogging, evaporation retarder, or prompt curing
- b.Use a higher-slump mix and delay finishing
- c.Add extra retarder and leave it exposed
- d.Increase the mix water to keep it workable
Answer: a
Explanation: In hot, windy conditions rapid evaporation causes plastic shrinkage cracking, so the priority is reducing moisture loss with fogging, evaporation retarders, and prompt curing. Adding mix water raises the water-cement ratio and weakens the concrete; leaving it exposed worsens evaporation.
Source: 2025 CA Building Code, Chapter 19 (Concrete)
3. Core Trades
The MOST reliable method to prevent backflow contamination of the potable water supply at a fixture is:
- a.Increasing the supply water pressure
- b.Installing a single check valve
- c.Adding length to the supply pipe
- d.Providing a physical air gap of adequate height above the fixture flood rim
Answer: d
Explanation: A physical air gap (an unobstructed vertical space, typically at least twice the pipe diameter and not less than 1 inch, above the flood rim) cannot be defeated because there is no continuous path for backflow. Check valves are mechanical and can fail; higher pressure and longer pipe do nothing to stop back-siphonage.
Source: 2025 CA Plumbing Code §603.0
4. Core Trades
A trench measures 90 ft long, 3 ft wide, and 4 ft deep. How many bank (in-place) cubic yards of soil must be excavated?
- a.120 cubic yards
- b.40 cubic yards
- c.30 cubic yards
- d.20 cubic yards
Answer: b
Explanation: Volume = 90 x 3 x 4 = 1,080 cubic feet; 1,080 / 27 = 40 cubic yards. The 20 and 30 answers understate the cross-section, and 120 leaves the result in cubic feet without dividing by 27.
5. Finish Trades
Under CALGreen, composite wood used in interior casework, such as particleboard cabinet boxes, must meet formaldehyde emission limits. This requirement is set MAINLY to:
- a.Lower the cost of the cabinets
- b.Make the cabinets waterproof
- c.Protect indoor air quality and occupant health
- d.Increase the strength of the cabinets
Answer: c
Explanation: CALGreen caps formaldehyde emissions from composite wood products (matching CARB standards) to protect indoor air quality and occupant health. The limits are about emissions, not structural strength, cost, or water resistance.
Source: 2025 CALGreen §4.504
6. Framing & Structural
A weep screed at the base of a stucco wall must be located at least how far above adjacent surfaces?
- a.At least 4 inches above earth or 2 inches above paved areas
- b.Flush with the finished grade
- c.At least 8 inches above paved areas
- d.At least 12 inches above earth
Answer: a
Explanation: The foundation weep screed must sit a minimum of 4 inches above earth or 2 inches above paved surfaces so moisture in the stucco can drain out above the splash and grade line. Twelve inches, flush with grade, and 8 inches above paving are not the code-required minimums.
Source: 2025 CA Residential Code §R703.7.2.1
7. Finish Trades
When applying an oil-based stain and clear topcoat to interior wood trim, why should oily rags be spread out or placed in a sealed metal container after use?
- a.To speed the drying of the topcoat
- b.To keep them clean for reuse
- c.Because they can spontaneously combust as the oil oxidizes and generates heat
- d.To prevent the stain color from fading
Answer: c
Explanation: Rags soaked with oil-based finishes can self-heat as the oil oxidizes and may spontaneously ignite if bunched up, so they must be spread flat to cool or sealed in a listed metal container with water. Reuse, color fading, and topcoat drying are not the safety reason for this practice.
8. Planning & Estimating
A roof has 1,800 square feet of surface. Adding 10 percent for waste, how many roofing squares should be ordered (1 square = 100 sq ft)?
- a.20 squares
- b.22 squares
- c.19 squares
- d.18 squares
Answer: a
Explanation: One roofing square covers 100 sq ft. Base area = 1,800 / 100 = 18 squares. Add 10 percent waste: 18 x 1.10 = 19.8 squares. Since material is sold in whole squares and you cannot under-order, round up to 20 squares. Option d ignores waste. Option c rounds 19.8 down, leaving a shortage. Always round material orders up.
9. Safety
A straight (non-self-supporting) ladder is set up against a wall. What placement BEST follows the recommended angle for safe use?
- a.Any angle is fine if the top is tied off
- b.Base 1 foot out for every 4 feet of working height
- c.Base 4 feet out for every 1 foot of working height
- d.Base directly against the wall, nearly vertical
Answer: b
Explanation: The safe setup is roughly a 4-to-1 ratio: the base should be about 1 foot away from the wall for every 4 feet of working height. Option c reverses the ratio, making the ladder dangerously flat. Option d is nearly vertical and prone to tipping backward. Option a ignores the angle even though tying off is also good practice. The 4-to-1 rule keeps the ladder stable against sliding and tipping.
Source: Cal/OSHA Title 8 §1675
10. Planning & Estimating
Match each work item to its CSI MasterFormat division: (i) built-up roofing and wall insulation, (ii) interior painting and ceramic tile, (iii) exterior aluminum windows.
- a.(i) 08, (ii) 07, (iii) 09
- b.(i) 07, (ii) 09, (iii) 08
- c.(i) 09, (ii) 07, (iii) 05
- d.(i) 05, (ii) 08, (iii) 07
Answer: b
Explanation: Correct: roofing, waterproofing, and insulation are Division 07 (Thermal & Moisture Protection); painting and tile are Division 09 (Finishes); windows and doors are Division 08 (Openings). The other options scramble these assignments.

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