CSLB C-9 Drywall (Trade Exam) Practice Test
| Administering body | Contractors State License Board (CSLB), California Department of Consumer Affairs — exam delivered by PSI Services LLC |
|---|---|
| Questions | Not published by CSLB What we read and found nothing in: CSLB — Step 7: Studying for the Examination |
| Time limit | 210 minutes |
| Passing score | Not published by CSLB What we read and found nothing in: CSLB — Step 7: Studying for the Examination |
| Fees |
Source: CSLB — List of All CSLB Fees |
| Languages offered | English · Spanish |
Frequently asked questions
How many CSLB Trade — Drywall (C-9) practice questions are here?+
A full bank of original CSLB Trade — Drywall (C-9) practice questions across the official content areas, weighted like the real exam, with explanations. Free, no signup.
What is the CSLB Trade — Drywall (C-9) exam like?+
A multiple-choice exam, 210 minutes. Practice by topic here, then take the full timed mock exam to gauge readiness.
Are these the real exam questions?+
No. Every question is 100% original, written from public primary sources with explanations. We never copy real exam questions or paid prep material.
Can I study in Chinese or Spanish?+
PrepPass practice is in English, 中文 and Español. The official exam is in English — switch the question language to English any time to rehearse the exact terminology you'll see on test day.
Sample practice questions
A few sample questions from this free bank, with full explanations. Use the practice tool above for the whole set.
- 1. Planning and Estimating
On a detail drawn at 1/2 inch = 1 foot, a soffit measures 7-3/4 inches. How long is the soffit?
- a.7-3/4 feet
- b.31 feet
- c.15-1/2 feet
- d.3-7/8 feet
Answer: c
Explanation: At 1/2 inch to the foot each inch of drawing is 2 feet, so 7.75 × 2 = 15.5 feet. Thirty-one feet is the reading at 1/4 inch = 1 foot, 7-3/4 feet ignores the scale, and 3-7/8 feet divides by 2 instead of multiplying.
Source: CSLB C-9 study guide 13E-9 (computation questions)
- 2. Planning and Estimating
One manufacturer lists its 1/2-inch regular glass-mat panel at a nominal 2.0 pounds per square foot. About what do 50 sheets of 4 × 8 panel weigh?
- a.3,200 pounds
- b.64 pounds
- c.3,840 pounds
- d.1,600 pounds
Answer: a
Explanation: One sheet is 32 square feet × 2.0 = 64 pounds, and 50 sheets weigh 3,200 pounds. Sixty-four pounds is a single sheet, 1,600 pounds is 25 sheets, and 3,840 pounds uses the same sheet's 2.4-pound figure for its 5/8-inch Type X glass-mat panel.
Source: USG glass-mat panel data sheet (weights)
- 3. Preparation, Framing, and Layout
Under the federal gypsum board specification, which work is scheduled after the gypsum board is applied?
- a.The framing inspection
- b.The roof covering
- c.The acoustic ceiling
- d.The HVAC start-up
Answer: c
Explanation: The specification says "Apply gypsum board prior to the installation of finish flooring and acoustic ceiling," so the acoustic ceiling follows. The framing inspection, a weathertight roof and operating HVAC are all preconditions that come before board.
Source: UFGS 09 29 00 §1.6
- 4. Preparation, Framing, and Layout
Under the federal gypsum board specification, when should the drywall contractor confirm that blocking for towel bars and grab bars is in place?
- a.Before hanging board
- b.After the painter's first coat
- c.When the owner asks for it
- d.After taping the joints
Answer: a
Explanation: The specification's examination step says to check that blocking and supports "are in place to support plumbing fixtures and to receive soap dishes, grab bars, towel racks, and similar items," and not to proceed until framing is acceptable. After taping or painting is too late, and the duty does not depend on a request.
Source: UFGS 09 29 00 §3.1.1
- 5. Installation and Repair
What perimeter blocking does the Building Code require for a gypsum diaphragm ceiling?
- a.A single 1 × 4 furring strip
- b.Steel track screwed to the joists
- c.Flat 2 × 6 wood blocking
- d.No blocking if screws are used
Answer: c
Explanation: Perimeter edges are blocked with wood "not less than 2-inch by 6-inch" nominal, installed flat over the top plate to give at least a 2-inch nailing surface. A 1 × 4, steel track, or no blocking does not meet the rule.
Source: CBC §2508.6.3
- 6. Installation and Repair
What is the maximum spacing between identification stencils along a fire barrier in an accessible concealed space?
- a.100 feet
- b.50 feet
- c.15 feet
- d.30 feet
Answer: d
Explanation: Identification must be "within 15 feet ... of the end of each wall and at intervals not exceeding 30 feet." Fifteen feet is the end distance, and 50 and 100 feet exceed the interval.
Source: CBC §703.5
- 7. Installation and Repair
What does the federal specification say about exterior gypsum soffit board?
- a.It may be used where water drains across it
- b.Install it with no ventilation to keep it dry
- c.Keep water off it; ventilate
- d.It needs no joint treatment outdoors
Answer: c
Explanation: The specification says "Do not install gypsum soffits in a manner that could allows liquid water to contact the gypsum soffits" and to provide ventilated soffits. Unventilated or water-washed soffits contradict it, and exterior joints are treated per the compound maker's instructions.
Source: UFGS 09 29 00 §3.2.10
- 8. Finishing
Before using a ready-mixed compound, how long does one manufacturer say to condition it at 55 to 95°F?
- a.1 hour
- b.24 hours
- c.7 days
- d.No conditioning is needed
Answer: b
Explanation: The sheet says "Before applying joint compound, store at 55-95°F (13-35°C) for 24 hours. Remix contents before use." One hour and seven days are not its figure, and it does call for conditioning.
Source: USG Midweight data sheet
- 9. Finishing
Under typical conditions, how soon may one manufacturer's spray texture be painted?
- a.After 30 days of curing
- b.Immediately while wet
- c.It is left unpainted as a finish
- d.After overnight drying
Answer: d
Explanation: The sheet says the texture "May be painted after overnight drying," dries to touch in 1 to 2 hours at 75°F and 50% humidity, and "Should be overpainted when dry. Not washable unpainted." Painting while wet, waiting 30 days, or leaving it unpainted contradict those directions.
Source: USG spray texture submittal 09800
- 10. Safety
In what year was the federal ban on consumer patching compounds containing respirable free-form asbestos issued?
- a.1977
- b.2005
- c.1990
- d.1957
Answer: a
Explanation: 16 CFR Part 1304 was published at 42 FR 63362 on December 15, 1977. 1957 is twenty years too early, and 1990 and 2005 are long after the ban; compound sold before 1977 is why older buildings may still contain asbestos in patching and joint materials.
Source: 16 CFR Part 1304