CSLB C-9 Drywall (Trade Exam) — All Questions

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✓

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.CBC §703.5

Which of the following is listed as a fireblocking material in the Residential Code?

• a.One-quarter-inch hardboard
• b.Loose-fill insulation, untested
• c.One-half-inch gypsum board✓
• d.Building paper

R302.11.1 lists "One-half-inch (12.7 mm) gypsum board" among fireblocking materials. Quarter-inch hardboard and building paper are not listed, and loose-fill may be used only if specifically tested in the form intended.CRC §R302.11.1

The Building Code requires fireblocking at interconnections between concealed vertical and horizontal spaces. Which locations does Section 718.2.3 name as examples?

• a.Attic access openings
• b.Window and door headers
• c.Soffits and drop ceilings✓
• d.Exterior wall sheathing joints

Section 718.2.3 requires fireblocking at interconnections "such as occur at soffits, drop ceilings, cove ceilings and similar locations." Window and door headers, sheathing joints and attic access openings are not concealed vertical-to-horizontal interconnections and are not the examples it names.CBC §718.2.3

In a building that is not Group R and not sprinklered, how large may a combustible attic space be before draftstops are required?

• a.500 square feet
• b.3,000 square feet✓
• c.1,000 square feet
• d.10,000 square feet

Draftstops subdivide combustible attic spaces "such that any horizontal area does not exceed 3,000 square feet." One thousand square feet is the floor-ceiling figure, and 500 and 10,000 are not code values.CBC §718.4

In a house with habitable space over the garage, what protection does the Residential Code require on structure supporting the separation floor-ceiling?

• a.1/2-inch gypsum board or equivalent✓
• b.No protection if the garage has a door
• c.Fire-retardant paint
• d.At least 5/8-inch Type X board on both sides

Table R302.6 requires "Not less than 1/2-inch gypsum board or equivalent" on structure supporting the separation floor-ceiling. Five-eighths Type X is the ceiling under habitable rooms, paint is not listed, and a door does not replace the separation.CRC Table R302.6

Under the Residential Code's floor-protection rule, how much of a floor assembly may be left without the required membrane, with fireblocking at its perimeter?

• a.No unprotected area is allowed
• b.Up to 200 square feet per room
• c.80 square feet per story✓
• d.Up to 10 percent of the floor area

The exception allows unprotected portions where "The aggregate area of the unprotected portions does not exceed 80 square feet ... per story" and fireblocking surrounds them. Two hundred square feet per room and 10 percent are not the code figures, and allowing no unprotected area ignores the exception.CRC §R302.13 Exception

What laboratory sound transmission class must walls between dwelling units meet under the Building Code?

• a.STC 50✓
• b.STC 35
• c.STC 60
• d.STC 45

Separating walls "shall have a sound transmission class of not less than 50 where tested in accordance with ASTM E90," or NNIC 45 if field tested. Thirty-five is too low, 45 is the field-test figure, and 60 is more than required.CBC §1206.2

Under the federal specification, how is a sound-rated partition sealed where it meets the floor, ceiling and other walls?

• a.With a gap left open for movement
• b.With paper tape on the room side
• c.With joint compound on one side
• d.Sealant or foam on both sides✓

Sound-rated partitions are sealed "continuously with acoustical foam or sealant (both sides)" wherever they abut another element. Tape, an open gap and one-sided compound let sound leak around the assembly.UFGS 09 29 00 §3.7

May regular gypsum wallboard be used under wall tile outside tub and shower areas under the Building Code?

• a.Yes, installed to GA-216 or ASTM C840✓
• b.Yes, but on ceilings alone
• c.No, cement board is required there
• d.Yes, if it is 3/8 inch thick

The code says "Regular gypsum wallboard is permitted under tile or wall panels in other wall and ceiling areas when installed in accordance with GA 216 or ASTM C840." Cement board is required only in listed wet areas, and the rule is not limited by thickness or to ceilings.CBC §2509.2

In the federal specification's wet-area method, what goes behind cementitious backer units?

• a.No membrane; the units go on bare studs
• b.15-lb felt lapped 6 inches✓
• c.Foil-backed gypsum board
• d.Polyethylene sheet with taped seams

The specification places "a 7.6 kg 15 lb asphalt impregnated, continuous felt paper membrane behind cementitious backer units ... with a minimum 150 mm 6 inch overlap of sheets laid shingle style." Polyethylene, foil-backed board and bare studs are not its method.UFGS 09 29 00 §3.3.1

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

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.UFGS 09 29 00 §3.2.10

May gypsum wallboard be used as the backing for cement plaster (stucco) on an exterior wall under the Building Code?

• a.Yes, if it is Type X
• b.Yes, if the stucco is one coat
• c.No, with narrow exceptions✓
• d.Yes, on exterior walls generally

The code says "Gypsum lath or gypsum wallboard shall not be used as a backing for cement plaster," with a narrow exception using a water-resistive barrier on horizontal supports of ceilings or roof soffits. Type X or a one-coat system does not create an exception for walls.CBC §2510.5.2.1

One manufacturer's J-stop metal trim is described how?

• a.Corner bead finished with three coats
• b.A reveal trim needing no compound✓
• c.A trim installed after taping
• d.A control joint for rated walls

The data sheet describes the J-stop trims as "used for reveal-type edge protection and requires no finishing compound," applied before the panels go up. Corner bead takes coats of compound, control joints are a different accessory, and J-stop goes on before the board.USG metal bead and trim submittal J1572

Under the Veterans Affairs specification, how must damaged finish in a non-decorated fire-rated wall be repaired?

• a.Retaped and refinished as rated✓
• b.Left as is, because it will not be painted
• c.Painted with intumescent paint
• d.Covered with a decorative panel

The specification requires damaged surfaces "including cracks and joints in non-decorated surface" to be taped and refinished "to provide fire protection equivalent to the fire rated construction." Leaving it, covering it or painting it does not restore the treated assembly.VA 09 29 00 §3.5.D

Under the federal specification's compound categories, what is an all-purpose compound made to do?

• a.Laminate board to concrete
• b.Fill fire-rated control joints
• c.Set chemically for use with mesh tape
• d.Serve for both taping and finishing✓

The specification defines all-purpose compound as made "to serve as both a taping and a finishing compound." Setting compound is the type for mesh tape, laminating is a use one maker lists for setting compound, and control joints in rated walls are backed with firestopping insulation.UFGS 09 29 00 §2.1.9.3

A finisher is using a ready-mixed (drying-type) compound. Which tape may be embedded in it?

• a.Self-adhering fiberglass mesh tape
• b.Paper joint tape✓
• c.Duct tape
• d.Self-adhering mesh with a quick coat

One manufacturer's ready-mix instructions say to "embed paper tape," and the federal specification bars self-adhering mesh tape with drying-type compounds. Duct tape is not joint tape, and a quick coat does not change the mesh rule.UFGS 09 29 00 §3.4; USG Midweight data sheet

In one manufacturer's setting compound line, what is the approximate working time of the "20" product?

• a.45 minutes
• b.20 minutes✓
• c.5 minutes
• d.2 hours

The suffix indicates "an approximate working time," and the 20 product lists 20 minutes of working time and 25 to 35 minutes to set. Five minutes is the 5 product, 45 minutes the 45 product, and 2 hours is not that product's figure.USG Easy Sand data sheet

How much setting compound should be mixed at one time, according to one manufacturer's data sheet?

• a.A full day's supply in one batch
• b.Enough to fill the whole bucket
• c.What can be used within the working time✓
• d.Half a bag per batch

The data sheet says "Mix what can be used within the working time. Use a clean container for each batch." A day's supply or a full bucket will set before it is used, and a fixed half bag ignores the working time.USG Easy Sand data sheet

A finisher plans to skim coat an entire wall for a Level 5 finish. Which compound type does one setting compound manufacturer say NOT to use for thin skim coats?

• a.Setting-type joint compound✓
• b.Ready-mixed all-purpose compound
• c.A primer-surfacer made for Level 5
• d.Ready-mixed lightweight compound

The setting compound sheet says "Do not use setting-type joint compounds for thin skim coats," while ready-mixed compounds can be used for skim coating when properly prepared, and a primer-surfacer is an accepted Level 5 alternative.USG Easy Sand data sheet (limitations)

Can one manufacturer's lightweight setting compound be run through mechanical taping tools?

• a.Yes, if a retarder is not used
• b.Yes, it is designed for mechanical tools
• c.No, it is not recommended✓
• d.Yes, if thinned with hot water

The data sheet lists "Not recommended for use in mechanical tools" among its limitations. It is described for hand-tool use, and thinning or additives do not change that limitation.USG Easy Sand data sheet (limitations)

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

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.USG Midweight data sheet

A ready-mixed compound is too stiff to tape with. How does one manufacturer say to thin it?

• a.Add a full gallon of water at once
• b.Add paint thinner
• c.Add setting compound powder
• d.Add water by the half-pint✓

The instruction is to "Add clean water in half-pint increments, remix and trial apply," warning that over-dilution causes shrinkage and poor bond and that it should not be mixed with other material. A gallon at once risks over-dilution, and powder or thinner are other materials.USG Midweight data sheet

In a manufacturer's summary of GA-214, how many separate coats of compound cover fastener heads at Level 4?

• a.0 coats
• b.3 coats✓
• c.2 coats
• d.1 coat

At Level 4, "Fastener heads and accessories shall be covered with three (3) separate coats of joint compound." One coat is Level 2, two coats is Level 3, and zero ignores the fastener coats every level from 2 up requires; Level 1 treats only joints and interior angles.GA-214 as summarized by CertainTeed

Under the Veterans Affairs specification, which level of finish is used in utility, maintenance and service areas?

• a.Level 5
• b.Level 2✓
• c.Level 1
• d.Level 4

The specification uses "level 2 finish in utility, maintenance and service areas," Level 1 in plenums and attics, and Level 5 in finished areas open to public view. Level 4 is not its choice for any of those areas.VA 09 29 00 §3.4.B

Besides a skim coat of joint compound, what alternative does one manufacturer offer when a Level 5 finish is required?

• a.A primer-surfacer product✓
• b.An extra coat on the joints
• c.A heavier texture
• d.Gloss paint without primer

The data sheet says "As an alternative to skim coating, or when a Level 5 finish is required," use its primer-surfacer. Extra joint coats leave the paper unequalized, texture is a different finish, and unprimed gloss paint is what causes show-through.USG Firecode X data sheet (finishing)

When can the next coat go on over a setting-type compound, according to its data sheet?

• a.Before the previous coat begins to set
• b.After the previous coat has set✓
• c.After it has dried for 24 hours
• d.After sanding to bare paper

The sheet says "After compound has set, apply second coat," and its filling instructions add coats after each coat has set "but not necessarily dried." Waiting a day is unnecessary, coating before the set disturbs it, and sanding to paper removes the bed.USG Easy Sand data sheet

How far beyond the first coat does one manufacturer feather the second coat on a flat joint?

• a.About 6 inches
• b.About 1/2 inch
• c.It covers the same width
• d.About 2 inches✓

The ready-mix instructions say to "Apply second coat, feathering approximately 2 in. beyond first coat." Half an inch leaves a ridge, 6 inches is more than the instruction, and covering the same width does not feather the joint.USG Midweight data sheet

One manufacturer's older trim sheet says how many coats finish metal corner bead with regular compounds, and with its lightweight compounds?

• a.Two coats; three with lightweight compounds
• b.One coat with either compound
• c.Three; two with lightweight✓
• d.Four coats with either compound

The sheet says "Finish corner with three coats of joint compound; use only two coats with SHEETROCK Brand lightweight compounds." One coat is too few, the reversed counts misstate it, and four is not its figure.USG metal bead and trim submittal J1572

What does the federal specification say finishers should do to reduce sanding dust?

• a.Apply the coats as thick as possible
• b.Sand with the HVAC running on high
• c.Tool joints as smoothly as possible✓
• d.Skip primer so less dust collects

The specification says "Tool joints as smoothly as possible to minimize sanding and dust," and to protect workers, occupants and HVAC systems from gypsum dust. Thick coats create more sanding, running HVAC spreads dust, and primer is still required.UFGS 09 29 00 §3.4

Why does a spray texture manufacturer require a prime coat before texturing new drywall?

• a.To add fire resistance
• b.To make the texture dry slower
• c.To replace joint treatment
• d.To equalize surface porosity✓

The data sheet says "Application of a prime coat is necessary to equalize surface porosity." Primer is not described as a drying retarder or fire treatment, and joints and fasteners must already be treated.USG spray texture submittal 09800

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✓

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.USG spray texture submittal 09800

Under Cal/OSHA Title 8 Section 1509, where must the employer's Code of Safe Practices be kept on a construction job?

• a.On site, or with each supervisor✓
• b.Kept by the building inspector
• c.Filed at the company's home office
• d.Mailed to Cal/OSHA once a year

The Code "shall be posted at a conspicuous location at each job site office or be provided to each supervisory employee who shall have it readily available." A home-office file, an annual mailing and the inspector's records do not make it available on the job.T8 CCR §1509(c)

Under Cal/OSHA Title 8 Section 1510, who may operate equipment and machinery on a construction site?

• a.People the general contractor names
• b.Qualified persons✓
• c.Employees after one day on site
• d.Employees over 18

"The employer shall permit only qualified persons to operate equipment and machinery." Age, time on site or a general contractor's say-so do not make a person qualified.T8 CCR §1510(b)

When does Cal/OSHA Title 8 Section 3384 say gloves must NOT be worn?

• a.When mixing joint compound
• b.Where machinery could catch them✓
• c.When cutting board with a utility knife
• d.When handling sheets of drywall

Gloves "shall not be worn where there is a danger of the hand protection becoming entangled in moving machinery or materials." Handling board, cutting and mixing are tasks where hand protection may be required against cuts and abrasions.T8 CCR §3384(b)

Which hazard named in Cal/OSHA Title 8 Section 3385 calls for protective footwear on a drywall job?

• a.Falling objects✓
• b.Using a laser level
• c.Working near a window
• d.Working on a cloudy day

Foot protection is required for employees exposed to foot injuries from "falling objects, crushing or penetrating actions" and similar hazards. Windows, weather and laser levels are not the listed hazards.T8 CCR §3385(a)

Under Table N-1 of Cal/OSHA Title 8 Section 5096, what is the highest sound level permitted for a full 8-hour workday?

• a.85 dBA
• b.100 dBA
• c.95 dBA
• d.90 dBA✓

The table permits 90 dBA for 8 hours; above that the permitted time shrinks, to 4 hours at 95 dBA. Eighty-five dBA is below the table's 8-hour level, and 95 and 100 dBA allow less than 8 hours.T8 CCR §5096 Table N-1

Under Cal/OSHA Title 8 Section 5144, what must an employer that requires respirator use have?

• a.A written program✓
• b.A box of respirators on site
• c.A sign at the entrance
• d.A verbal reminder at lunch

The section "requires the employer to develop and implement a written respiratory protection program with required worksite-specific procedures." Supplies, reminders and signs do not replace the program, medical evaluation and fit testing.T8 CCR §5144(c)

For a task listed on Table 1 of the construction silica standard, what must the employer do?

• a.No controls, if the task lasts under an hour
• b.Wet the floor once per shift
• c.Hand out dust masks
• d.Use its listed controls, or limit exposure✓

The employer "shall fully and properly implement the engineering controls, work practices, and respiratory protection specified for the task on Table 1, unless the employer assesses and limits the exposure" under subsection (d). A short task is not exempt, handing out dust masks skips the engineering controls and work practices Table 1 requires, and wetting the floor once a shift is not a listed control.T8 CCR §1532.3(c)

What does Cal/OSHA Title 8 Section 1528 say about spraying materials containing asbestos on a building under repair?

• a.It is allowed with a respirator
• b.It is allowed indoors
• c.It is allowed if under 100 square feet
• d.It is prohibited✓

"The spraying of any substance containing any amount of asbestos in or upon a building or other structure during its construction, alteration or repair is prohibited," with exceptions such as encapsulated coatings. Area, respirators and location do not create an exception.T8 CCR §1528(d)

A worker cleans up debris from asbestos repair work without disturbing intact material. How does Cal/OSHA Title 8 Section 1529 classify this?

• a.Class IV asbestos work✓
• b.Class I asbestos work
• c.Not asbestos work
• d.Class III asbestos work

"Class IV asbestos work" includes "activities to clean up dust, waste and debris resulting from Class I, II, and III activities." Class I is removal of TSI and surfacing material, Class III is repair that disturbs ACM, and cleanup of asbestos debris is regulated.T8 CCR §1529(b)

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

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.16 CFR Part 1304

Under the federal RRP rule, what is required of a high-speed power sander used on painted surfaces in target housing?

• a.A shroud with a HEPA vacuum✓
• b.No controls, if a dust mask is worn
• c.That the windows be open
• d.That the area be swept afterward

High-speed machines such as sanders are "prohibited on painted surfaces unless such machines have shrouds or containment systems and are equipped with a HEPA vacuum attachment." Masks, sweeping and open windows are not substitutes.40 CFR 745.85(a)(3)

Under the federal RRP rule, what must a firm have before performing renovations for pay in target housing?

• a.Liability insurance
• b.A CSLB license
• c.The owner's verbal permission
• d.Certification from EPA✓

"No firm may perform, offer, or claim to perform renovations without certification from EPA under § 745.89 in target housing or child-occupied facilities," unless an exception applies. A state license, permission or insurance does not replace EPA certification.40 CFR 745.81(a)(2)

Under Cal/OSHA's outdoor heat standard, which is one of the high-heat procedures required at 95°F?

• a.Stopping work above 95°F
• b.A mandatory 30-minute break every hour
• c.Moving the work indoors
• d.Pre-shift heat meetings✓

High-heat procedures include "Pre-shift meetings before the commencement of work to review the high heat procedures, encourage employees to drink plenty of water," along with observation and communication. The standard does not set a 30-minute hourly break, a work stoppage or a move indoors.T8 CCR §3395(e)(5)

Under Cal/OSHA's outdoor heat standard, how long must an employee newly assigned to a high-heat area be closely observed?

• a.If the employee asks
• b.For the first day
• c.For the first 14 days✓
• d.For the first 30 days

An employee "newly assigned to a high heat area shall be closely observed by a supervisor or designee for the first 14 days." One day, 30 days and observation on request are not the rule.T8 CCR §3395(g)

Under Cal/OSHA's indoor heat standard, at what heat index do the assessment and control measures apply, regardless of clothing or radiant heat?

• a.95°F
• b.80°F
• c.82°F
• d.87°F✓

The control measures apply where the temperature or "The heat index equals or exceeds 87 degrees Fahrenheit." Eighty-two degrees triggers the section and the measures only with restrictive clothing or radiant heat, 80°F is the outdoor shade trigger, and 95°F is the outdoor high-heat trigger.T8 CCR §3396(a)(2)

What load must a cover over a floor opening support under Cal/OSHA Title 8 Section 1632?

• a.400 lb or twice the load, if greater✓
• b.100 pounds at the center
• c.200 pounds per square foot
• d.The weight of one worker

Covers must safely support "the greater of 400 pounds or twice the weight of the employees, equipment and materials that may be imposed on any one square foot area of the cover at any time." 100 pounds at the center and one worker's weight fall below the 400-pound floor and ignore doubling the imposed load, and 200 pounds per square foot is not the section's figure.T8 CCR §1632(b)(3)

Under Cal/OSHA Title 8 Section 1646, what is required of the casters on a rolling scaffold?

• a.Rubber tires, no locks
• b.Locks, engaged during work✓
• c.Four fixed, non-swivel casters
• d.No requirement if the floor is level

Casters must have "an effective locking device, and kept locked when workers are climbing or working," and at least 2 of the 4 must swivel. Four fixed casters, unlocked tires and a level floor do not meet the rule.T8 CCR §1646(c)

One employee wants to ride and move a rolling scaffold alone from its platform. Under Cal/OSHA Title 8 Section 1646, how high may the platform be?

• a.No more than 4 feet above the floor✓
• b.No more than 8 feet above the floor
• c.No more than 12 feet above the floor
• d.Higher, if the base is wide

For self-propelled riding, "The scaffold platform shall not be more than 4 feet above the floor level," among other conditions. Eight and 12 feet exceed it, and base width does not lift the height limit.T8 CCR §1646(j)(2)

Under Cal/OSHA Title 8 Section 1637, how often must scaffold planks be visually inspected?

• a.Once a month
• b.After a fall
• c.Daily, before use✓
• d.Once a week

"All scaffold planks shall be visually inspected for defects before use each day," and defective planks are removed from service. Weekly, monthly or after-the-fact inspections are not the rule.T8 CCR §1637(f)(6)