California CSLB C-9 Drywall Examination

A contractor is estimating drywall for a commercial office room measuring 30 ft by 40 ft with a 10 ft ceiling height. Assuming 4 ft by 12 ft sheets and adding a 10% waste factor, how many drywall sheets are required for the walls and flat ceiling combined?

• A60 sheets of 4' x 12' drywall
• B72 sheets of 4' x 12' drywall
• C48 sheets of 4' x 12' drywall
• D84 sheets of 4' x 12' drywall

For a commercial drywall project covering 8,000 sq ft of wallboard, how many 5-gallon buckets of ready-mix joint compound should be estimated for a standard Level 4 finish?

• A24 five-gallon buckets of compound
• B16 five-gallon buckets of compound
• C32 five-gallon buckets of compound
• D08 five-gallon buckets of compound

An estimator is calculating paper joint tape requirements for a 12,000 sq ft drywall installation. How many standard 500-foot rolls of tape are required for this scope?

• A15 rolls of 500-foot paper tape
• B20 rolls of 500-foot paper tape
• C09 rolls of 500-foot paper tape
• D30 rolls of 500-foot paper tape

How many 1-1/4 inch drywall screws are required to fasten 150 sheets of 4 ft by 8 ft gypsum board to wall studs spaced 16 inches on center?

• A3,200 drywall screws total
• B6,400 drywall screws total
• C2,100 drywall screws total
• D4,800 drywall screws total

A C-9 contractor is framing a straight 160-foot non-load-bearing partition wall with metal studs placed 16 inches on center. How many steel studs are needed, excluding corners and openings?

• A121 steel studs required
• B101 steel studs required
• C141 steel studs required
• D161 steel studs required

When planning a commercial project with 9-foot ceiling heights, which panel size minimizes horizontal butt joints and overall labor?

• A4 ft by 08 ft panels hung vertically only
• B5 ft by 10 ft panels hung horizontally
• C4 ft by 10 ft panels hung vertically
• D4 ft by 12 ft panels hung vertically

A 20-foot long by 10-foot high interior acoustic partition requires resilient channels (RC-1) installed horizontally at 24 inches on center. What total linear feet of RC-1 channel is needed?

• A160 linear feet of RC-1
• B240 linear feet of RC-1
• C120 linear feet of RC-1
• D080 linear feet of RC-1

A 2-hour fire-rated corridor partition wall measuring 100 feet long by 10 feet high requires double-layer 5/8-inch Type X gypsum board on both sides. How many 4' x 10' sheets are needed without waste?

• A025 sheets of 4' x 10' panels
• B050 sheets of 4' x 10' panels
• C075 sheets of 4' x 10' panels
• D100 sheets of 4' x 10' panels

A commercial project contains 45 exterior wall corners with 9-foot ceilings. How many standard 10-foot metal corner beads must be ordered to trim all corners?

• A45 ten-foot corner beads
• B50 ten-foot corner beads
• C35 ten-foot corner beads
• D60 ten-foot corner beads

When estimating joint compound for a Level 5 skim coat over 5,000 sq ft of wallboard, how much additional ready-mix compound is needed beyond a Level 4 finish?

• A10 to 12 additional gallons
• B35 to 40 additional gallons
• C70 to 80 additional gallons
• D15 to 20 additional gallons

Which gypsum board material must be specified for wall substrates in tub and shower compartments subject to direct water exposure under CBC Chapter 25?

• AStandard Type X gypsum board
• BWater-resistant greenboard panel
• CCementitious backer unit (CBU)
• DFaced paper-less gypsum board

A 5/8-inch Type X drywall panel weighs approximately 2.2 lbs per square foot. What is the total weight of a pallet containing 40 sheets of 4 ft by 12 ft panels?

• A3,228 pounds total weight
• B5,120 pounds total weight
• C1,840 pounds total weight
• D4,224 pounds total weight

If a two-man hanging crew averages 50 sheets of 4' x 12' drywall per 8-hour shift, what is their labor production rate in square feet per man-hour?

• A150 square feet per man-hour
• B300 square feet per man-hour
• C200 square feet per man-hour
• D100 square feet per man-hour

When estimating perimeter acoustical sealant for STC-rated wall assemblies, how many 28-ounce tubes are needed for 1,000 linear feet of track with a 1/4-inch bead?

• A12 tubes of acoustic caulk
• B24 tubes of acoustic caulk
• C48 tubes of acoustic caulk
• D36 tubes of acoustic caulk

In commercial drywall estimating, what is the standard recommended waste factor applied to drywall materials for complex soffits and angled corridor layouts?

• A03% to 05% waste allowance
• B08% to 10% waste allowance
• C15% to 20% waste allowance
• D25% to 30% waste allowance

According to GA-216 and ASTM C840, what is the maximum continuous distance allowed for a drywall partition wall before a control joint must be specified?

• A50 linear feet maximum
• B20 linear feet maximum
• C40 linear feet maximum
• D30 linear feet maximum

A 40 ft by 60 ft commercial ceiling requires 5/8-inch Type X drywall installed on steel framing. Including a standard 10% waste factor, how many 4 ft by 12 ft sheets are required?

• A55 sheets of 4' x 12' board
• B65 sheets of 4' x 12' board
• C45 sheets of 4' x 12' board
• D75 sheets of 4' x 12' board

On architectural construction drawings, what symbol or designation typically identifies a 1-hour fire-rated drywall partition assembly?

• ASTC 50 acoustical partition schedule tag
• BUL Design U419 fire assembly callout
• CASTM C840 Level 4 finish schedule tag
• DGA Level 5 skim coat specification tag

According to ASTM C754 and CBC Chapter 25, what is the maximum allowable spacing for floor and ceiling track fasteners in non-load-bearing steel stud partitions?

• A36 inches on center maximum
• B16 inches on center maximum
• C24 inches on center maximum
• D48 inches on center maximum

Under GA-216 and ASTM C840, what is the maximum stud spacing permitted for 1/2-inch single-layer gypsum wallboard installed perpendicular to wall framing?

• A16 inches on center spacing
• B12 inches on center spacing
• C20 inches on center spacing
• D24 inches on center spacing

Why are vertical steel studs cut 1/2-inch short of the top runner track height in commercial interior partition framing?

• ATo accommodate vertical floor/ceiling slab deflection
• BTo allow horizontal expansion of gypsum panels
• CTo provide ventilation clearance inside wall studs only
• DTo facilitate electrical conduit routing at tracks

Prior to installing gypsum wallboard over wood framing, what is the maximum allowable moisture content of the wood studs per GA-216?

• A25% maximum moisture content
• B19% maximum moisture content
• C12% maximum moisture content
• D30% maximum moisture content

According to ASTM C754, what is the maximum allowable out-of-plumb framing tolerance for a 10-foot vertical steel stud partition?

• A1/4 inch in 10 feet plumbness
• B1/2 inch in 10 feet plumbness
• C1/8 inch in 10 feet plumbness
• D3/8 inch in 10 feet plumbness

When attaching RC-1 resilient channels horizontally to wood wall studs for sound isolation, how must the attachment leg be oriented?

• AAttachment leg facing sideways
• BAttachment leg facing upward
• CAttachment leg facing alternating
• DAttachment leg facing downward

How should steel studs framing a heavy hollow metal door opening be reinforced to prevent door-slamming vibration cracks?

• ANest wood or steel stud inside door jamb stud
• BApply extra joint compound along frame edge
• CSpace adjacent wall studs at 8 inches on center
• DUse 1/4-inch thick gypsum board around opening

What is the standard spacing for horizontal hat-channel (furring channel) when applying gypsum board to concrete masonry unit (CMU) walls?

• A12 inches on center spacing
• B24 inches on center spacing
• C36 inches on center spacing
• D48 inches on center spacing

What structural backing requirement must be installed inside wall framing prior to drywall inspection for wall-hung lavatories and grab bars under CBC?

• A1/2-inch plywood or 2x6 wood/steel backing plates
• BDouble layer of 5/8-inch Type X drywall panel
• CMinimum 2x6 solid wood or 16-gauge steel backing
• DExpanded wire lathing behind drywall panels

In double-stud acoustic wall construction, what framing detail prevents sound flank transmission between the two parallel stud rows?

• AContinuous steel track connecting both rows
• B1-inch minimum air gap with no physical contact
• CRigid metal bridging clips spaced 16 in o.c.
• DPhysical separation with 1-inch minimum air gap

According to ASTM C754, what is the maximum main runner channel spacing for a direct-hung suspended steel ceiling frame supporting 5/8-inch gypsum board?

• A4 feet on center maximum
• B6 feet on center maximum
• C2 feet on center maximum
• D5 feet on center maximum

Where must expansion relief joints be located in large drywall suspended ceiling assemblies under ASTM C840?

• AAt maximum intervals of 100 feet in both directions
• BAt maximum intervals of 50 feet in both directions
• CAt maximum intervals of 25 feet in both directions
• DAt maximum intervals of 75 feet in both directions

When framing a metal stud wall with 25-gauge (18 mil) studs, what fastener type must be used to connect metal tracks to studs?

• A1-1/4 inch Type S bugle head drywall screws
• B1-1/2 inch Type W coarse thread wood screws
• C7/16 inch Type S pan head framing screws
• D1-1/2 inch Type S-12 self-drilling TEK screws

Which tool method provides the most accurate 90-degree square reference layout line for establishing long commercial partition walls?

• AUsing a standard 24-inch framing square
• Bsnapping a single chalk line between points
• CUsing a 3-4-5 right triangle geometric layout only
• DUsing the 3-4-5 right triangle method or laser

According to GA-216, how far must vertical end joints (butt joints) be offset/staggered between adjacent courses of gypsum wallboard?

• AAt least 12 inches between adjacent courses
• BAt least 06 inches between adjacent courses
• CAt least 24 inches between adjacent courses
• DNo offset required if joints fall on studs

What is the minimum fastener penetration required into wood framing members when installing 5/8-inch gypsum wallboard per ASTM C840?

• A1/4 inch minimum penetration into wood
• B5/8 inch minimum penetration into wood
• C1 inch minimum penetration into wood
• D3/8 inch minimum penetration into wood

In commercial wall applications, why is horizontal panel installation generally preferred over vertical installation under GA-216?

• AIt increases wall acoustic STC ratings significantly higher
• BIt uses less joint tape than vertical panels
• CIt ties more studs together and places joints at eye level
• DIt eliminates the need for perimeter screw fasteners

What is the correct depth of a properly driven drywall screw in gypsum board per ASTM C840?

• ADriven flush with the paper surface without recess
• BPushed 1/8 inch deep, puncturing the face paper
• CSlightly recessed below surface without tearing paper
• DRecessed in a slight dimple without breaking paper

Under GA-216, what is the maximum screw spacing along framing members for 1/2-inch gypsum ceiling board attached to wood joists spaced 16 in o.c.?

• A12 inches on center maximum screw spacing
• B16 inches on center maximum screw spacing
• C24 inches on center maximum screw spacing
• D08 inches on center maximum screw spacing

What core composition distinguishes Type X gypsum board from standard interior wallboard under ASTM C1396?

• APolyurethane foam backing layer added
• BNoncombustible glass fibers added to core
• CPortland cement matrix mixed into gypsum only
• DAsbestos fiber reinforcement throughout

Where is Type C fire-rated gypsum board required instead of standard Type X board in UL-rated assemblies?

• AIn exterior wall soffit backing assemblies
• BIn wet shower room tile backer wall applications
• CIn fire-rated ceilings and roof-ceiling assemblies
• DIn soundproof interior double-stud wall partitions

According to ANSI A118.9 and ASTM C1325, what type of joint tape must be used to seal joints between cementitious backer units (CBU)?

• AStandard 2-inch paper joint tape with compound only
• BSelf-adhesive paper tape with setting compound
• CSelf-adhesive paper-backed aluminum foil tape
• DAlkali-resistant fiberglass mesh tape with thinset

Under CBC Chapter 25 and GA-216, what restriction applies to water-resistant gypsum backing board (greenboard) on ceilings?

• AFraming spacing cannot exceed 12 in o.c. for 1/2 in
• BGreenboard is forbidden on all interior ceilings too
• CGreenboard must be skim coated with Level 5 mud
• DIt must be installed parallel to ceiling joists

What specialized panel is installed in CH-stud friction-fit assemblies to construct elevator shaft fire barrier walls?

• A1/2-inch water-resistant paper-faced board
• B1-inch thick glass-mat shaftliner panels
• C5/8-inch Type C high-density ceiling board
• D1/4-inch flexible gypsum interior panels

When using drywall adhesive combined with screws to attach wallboard to wood framing per GA-216, what is the maximum screw spacing permitted in the field?

• A12 inches on center in field
• B16 inches on center in field
• C24 inches on center in field
• D32 inches on center in field

What is the correct procedure for making clean cuts in paper-faced gypsum panels per GA-216?

• ASaw through panel core using a fine tooth saw
• BScore core with utility knife then score back
• CCut through back paper first then break core
• DScore front paper, snap core, cut back paper

Why must gypsum wallboard be held 1/4-inch to 1/2-inch above the bare floor slab during wall installation?

• ATo prevent wicking floor moisture into gypsum core
• BTo allow floor baseboards to slide underneath
• CTo create an air vent for HVAC circulation
• DTo satisfy structural floor shear wall requirements

How must electrical outlet boxes installed on opposite sides of a 1-hour fire-rated drywall wall be spaced horizontally per CBC Chapter 7?

• ASpaced at least 12 inches apart horizontally
• BSpaced at least 24 inches apart horizontally
• CSpaced at least 36 inches apart horizontally
• DMay be mounted back-to-back in same stud cavity