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