CT Drywall Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the standard thickness for residential interior drywall?
A. 1/4 inch
B. 3/8 inch
C. 1/2 inch
D. 5/8 inch
Rationale: 1/2 inch drywall is the standard for most residential walls
and ceilings because it provides adequate strength and fire resistance.
2. Which type of drywall is typically used in moisture-prone areas like
bathrooms?
A. Standard drywall
B. Greenboard (moisture-resistant drywall)
C. Fire-rated drywall
D. Soundproof drywall
Rationale: Greenboard is treated to resist moisture, making it
suitable for bathrooms and kitchens.
3. What is the purpose of a vapor barrier behind drywall?
A. To increase insulation
B. To prevent moisture from entering wall cavities
C. To provide soundproofing
D. To support drywall attachment
Rationale: A vapor barrier prevents moisture from penetrating walls,
which can cause mold and structural damage.
4. Which drywall joint compound is easiest for beginners to use?
A. Taping compound
B. All-purpose compound
, C. Joint compound (pre-mixed)
D. Setting compound
Rationale: Pre-mixed joint compound is user-friendly and ready for
immediate application, making it suitable for beginners.
5. When installing drywall, studs should be spaced no more than:
A. 24 inches on center
B. 16 inches on center
C. 32 inches on center
D. 12 inches on center
Rationale: 16-inch spacing provides proper support and minimizes
sagging for standard drywall sheets.
6. Fire-rated drywall is often called:
A. Type X
B. Type C
C. Type F
D. Type X
Rationale: Type X drywall contains glass fibers and other additives to
improve fire resistance, making it suitable for fire-rated assemblies.
7. What is the recommended screw spacing for 1/2-inch drywall on walls?
A. 6 inches
B. 12 inches
C. 16 inches
D. 24 inches
Rationale: 16 inches on center for screws provides secure attachment
without compromising the drywall integrity.
8. Which tool is used to cut drywall around electrical outlets?
A. Hammer
B. Utility knife
C. Drywall keyhole saw
D. Circular saw
Rationale: A drywall keyhole saw allows precise cutting for outlets,
switches, and other openings.
9. When finishing drywall, how many coats of joint compound are
typically applied?
A. 1
B. 2
C. 3
, D. 4
Rationale: Three coats ensure smooth seams: a taping coat, a fill
coat, and a finishing coat.
10. Which type of tape is recommended for inside corners?
A. Paper tape
B. Paper tape
C. Fiberglass mesh tape
D. Metal tape
Rationale: Paper tape is stronger and better for inside corners
because it reduces cracking compared to mesh tape.
11. What is the maximum ceiling span for 1/2-inch drywall without
sagging?
A. 6 feet
B. 8 feet
C. 12 feet
D. 16 feet
Rationale: 1/2-inch drywall can span up to 12 feet horizontally when
properly supported on joists or furring strips.
12. Which of the following is an advantage of metal studs over wood
studs?
A. Lower cost
B. Easier to cut
C. Resistance to warping and termites
D. Heavier weight
Rationale: Metal studs do not warp, shrink, or suffer termite damage,
making them suitable for commercial applications.
13. The primary function of corner beads is to:
A. Add insulation
B. Decorate walls
C. Protect and reinforce corners
D. Support ceiling drywall
Rationale: Corner beads prevent damage to corners and create a
clean, straight edge.
14. What is the recommended screw type for attaching drywall to
metal studs?
A. Wood screws
B. Masonry screws
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the standard thickness for residential interior drywall?
A. 1/4 inch
B. 3/8 inch
C. 1/2 inch
D. 5/8 inch
Rationale: 1/2 inch drywall is the standard for most residential walls
and ceilings because it provides adequate strength and fire resistance.
2. Which type of drywall is typically used in moisture-prone areas like
bathrooms?
A. Standard drywall
B. Greenboard (moisture-resistant drywall)
C. Fire-rated drywall
D. Soundproof drywall
Rationale: Greenboard is treated to resist moisture, making it
suitable for bathrooms and kitchens.
3. What is the purpose of a vapor barrier behind drywall?
A. To increase insulation
B. To prevent moisture from entering wall cavities
C. To provide soundproofing
D. To support drywall attachment
Rationale: A vapor barrier prevents moisture from penetrating walls,
which can cause mold and structural damage.
4. Which drywall joint compound is easiest for beginners to use?
A. Taping compound
B. All-purpose compound
, C. Joint compound (pre-mixed)
D. Setting compound
Rationale: Pre-mixed joint compound is user-friendly and ready for
immediate application, making it suitable for beginners.
5. When installing drywall, studs should be spaced no more than:
A. 24 inches on center
B. 16 inches on center
C. 32 inches on center
D. 12 inches on center
Rationale: 16-inch spacing provides proper support and minimizes
sagging for standard drywall sheets.
6. Fire-rated drywall is often called:
A. Type X
B. Type C
C. Type F
D. Type X
Rationale: Type X drywall contains glass fibers and other additives to
improve fire resistance, making it suitable for fire-rated assemblies.
7. What is the recommended screw spacing for 1/2-inch drywall on walls?
A. 6 inches
B. 12 inches
C. 16 inches
D. 24 inches
Rationale: 16 inches on center for screws provides secure attachment
without compromising the drywall integrity.
8. Which tool is used to cut drywall around electrical outlets?
A. Hammer
B. Utility knife
C. Drywall keyhole saw
D. Circular saw
Rationale: A drywall keyhole saw allows precise cutting for outlets,
switches, and other openings.
9. When finishing drywall, how many coats of joint compound are
typically applied?
A. 1
B. 2
C. 3
, D. 4
Rationale: Three coats ensure smooth seams: a taping coat, a fill
coat, and a finishing coat.
10. Which type of tape is recommended for inside corners?
A. Paper tape
B. Paper tape
C. Fiberglass mesh tape
D. Metal tape
Rationale: Paper tape is stronger and better for inside corners
because it reduces cracking compared to mesh tape.
11. What is the maximum ceiling span for 1/2-inch drywall without
sagging?
A. 6 feet
B. 8 feet
C. 12 feet
D. 16 feet
Rationale: 1/2-inch drywall can span up to 12 feet horizontally when
properly supported on joists or furring strips.
12. Which of the following is an advantage of metal studs over wood
studs?
A. Lower cost
B. Easier to cut
C. Resistance to warping and termites
D. Heavier weight
Rationale: Metal studs do not warp, shrink, or suffer termite damage,
making them suitable for commercial applications.
13. The primary function of corner beads is to:
A. Add insulation
B. Decorate walls
C. Protect and reinforce corners
D. Support ceiling drywall
Rationale: Corner beads prevent damage to corners and create a
clean, straight edge.
14. What is the recommended screw type for attaching drywall to
metal studs?
A. Wood screws
B. Masonry screws
