CO Drywall Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the primary purpose of drywall in building
construction?
A. Structural support
B. Creating interior walls and ceilings
C. Waterproofing
D. Insulation
Rationale: Drywall is primarily used to form interior walls and
ceilings, providing a smooth surface for finishes.
2. What is the standard thickness of residential interior drywall?
A. 1/4 inch
B. 1/2 inch
C. 3/4 inch
D. 5/8 inch
Rationale: 1/2 inch drywall is standard for most residential interior
walls.
3. Type X drywall is commonly used for:
A. Fire-resistance applications
B. Soundproofing
C. Moisture resistance
D. Exterior siding
Rationale: Type X drywall contains special additives to increase fire
resistance.
4. What tool is used to cut drywall along straight lines?
A. Jigsaw
, B. Hammer
C. Utility knife
D. Circular saw
Rationale: A utility knife is used to score and snap drywall cleanly.
5. Which fastener is most commonly used to attach drywall to wood
studs?
A. Nails
B. Drywall screws
C. Staples
D. Bolts
Rationale: Drywall screws provide secure attachment and reduce the
risk of popping compared to nails.
6. When installing drywall on ceilings, it is recommended to:
A. Hang sheets parallel to joists
B. Hang sheets perpendicular to joists
C. Use adhesive only
D. Leave seams at random
Rationale: Perpendicular installation increases strength and reduces
sagging.
7. What is the purpose of joint compound?
A. Sanding drywall
B. Sealing seams and screw holes
C. Priming drywall
D. Structural reinforcement
Rationale: Joint compound fills seams, screw holes, and imperfections
for a smooth finish.
8. Paper-faced drywall tape is typically applied to:
A. Cover seams between drywall sheets
B. Cover nails only
C. Exterior walls
D. Insulation joints
Rationale: Paper tape reinforces seams and prevents cracks.
9. What is a common method to finish inside corners?
A. Fiberglass tape
B. Spray foam
C. Corner bead with joint compound
D. Caulk only
, Rationale: Metal or vinyl corner beads are applied to inside corners
and covered with joint compound for durability.
10. Greenboard drywall is designed specifically for:
A. Fire resistance
B. Moisture resistance
C. Soundproofing
D. Exterior walls
Rationale: Greenboard contains water-resistant cores for damp areas
like bathrooms.
11. What is the minimum drywall thickness required for ceilings in
residential construction?
A. 1/4 inch
B. 5/8 inch
C. 1/2 inch
D. 3/4 inch
Rationale: 5/8 inch is often required to prevent sagging on ceilings,
especially in larger spans.
12. What is the recommended screw spacing for 1/2 inch drywall on
walls?
A. 6 inches
B. 16 inches
C. 24 inches
D. 12 inches
Rationale: Screws are spaced 16 inches apart on studs to ensure
proper attachment.
13. How should drywall sheets be oriented on walls?
A. Horizontally or vertically depending on framing
B. Horizontally
C. Vertically
D. At 45-degree angles
Rationale: Horizontal installation provides more seam coverage and
strength, particularly on standard 8-foot walls.
14. Which type of drywall is used for soundproofing applications?
A. Type X
B. Acoustical drywall
C. Greenboard
D. Blueboard
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. Which of the following is the primary purpose of drywall in building
construction?
A. Structural support
B. Creating interior walls and ceilings
C. Waterproofing
D. Insulation
Rationale: Drywall is primarily used to form interior walls and
ceilings, providing a smooth surface for finishes.
2. What is the standard thickness of residential interior drywall?
A. 1/4 inch
B. 1/2 inch
C. 3/4 inch
D. 5/8 inch
Rationale: 1/2 inch drywall is standard for most residential interior
walls.
3. Type X drywall is commonly used for:
A. Fire-resistance applications
B. Soundproofing
C. Moisture resistance
D. Exterior siding
Rationale: Type X drywall contains special additives to increase fire
resistance.
4. What tool is used to cut drywall along straight lines?
A. Jigsaw
, B. Hammer
C. Utility knife
D. Circular saw
Rationale: A utility knife is used to score and snap drywall cleanly.
5. Which fastener is most commonly used to attach drywall to wood
studs?
A. Nails
B. Drywall screws
C. Staples
D. Bolts
Rationale: Drywall screws provide secure attachment and reduce the
risk of popping compared to nails.
6. When installing drywall on ceilings, it is recommended to:
A. Hang sheets parallel to joists
B. Hang sheets perpendicular to joists
C. Use adhesive only
D. Leave seams at random
Rationale: Perpendicular installation increases strength and reduces
sagging.
7. What is the purpose of joint compound?
A. Sanding drywall
B. Sealing seams and screw holes
C. Priming drywall
D. Structural reinforcement
Rationale: Joint compound fills seams, screw holes, and imperfections
for a smooth finish.
8. Paper-faced drywall tape is typically applied to:
A. Cover seams between drywall sheets
B. Cover nails only
C. Exterior walls
D. Insulation joints
Rationale: Paper tape reinforces seams and prevents cracks.
9. What is a common method to finish inside corners?
A. Fiberglass tape
B. Spray foam
C. Corner bead with joint compound
D. Caulk only
, Rationale: Metal or vinyl corner beads are applied to inside corners
and covered with joint compound for durability.
10. Greenboard drywall is designed specifically for:
A. Fire resistance
B. Moisture resistance
C. Soundproofing
D. Exterior walls
Rationale: Greenboard contains water-resistant cores for damp areas
like bathrooms.
11. What is the minimum drywall thickness required for ceilings in
residential construction?
A. 1/4 inch
B. 5/8 inch
C. 1/2 inch
D. 3/4 inch
Rationale: 5/8 inch is often required to prevent sagging on ceilings,
especially in larger spans.
12. What is the recommended screw spacing for 1/2 inch drywall on
walls?
A. 6 inches
B. 16 inches
C. 24 inches
D. 12 inches
Rationale: Screws are spaced 16 inches apart on studs to ensure
proper attachment.
13. How should drywall sheets be oriented on walls?
A. Horizontally or vertically depending on framing
B. Horizontally
C. Vertically
D. At 45-degree angles
Rationale: Horizontal installation provides more seam coverage and
strength, particularly on standard 8-foot walls.
14. Which type of drywall is used for soundproofing applications?
A. Type X
B. Acoustical drywall
C. Greenboard
D. Blueboard
