Arkansas AR-GP Gypsum &
Plaster Contractor Practice Exam
| Questions, Verified Answers &
Detailed Rationales | Complete
Contractor License Exam Prep
Study Guide | Updated 2026
1. What is the primary raw material used to manufacture
conventional gypsum plaster?
A. Portland cement
B. Hydrated lime
C. Gypsum
D. Silica sand
Answer: Gypsum
Rationale: Gypsum is calcium sulfate dihydrate and is
the principal mineral used to manufacture gypsum
plaster and gypsum board products.
2. What happens when calcined gypsum is mixed with water?
A. It becomes permanently flexible
B. It rehydrates and sets into a hardened gypsum
material
C. It changes into Portland cement
D. It becomes waterproof
Answer: It rehydrates and sets into a hardened gypsum
material
Rationale: Calcined gypsum reacts with water and
recrystallizes as gypsum, producing the setting and
hardening characteristics of gypsum plaster.
, 3. What is the primary purpose of gypsum wallboard?
A. Structural foundation support
B. Exterior roofing
C. Interior wall and ceiling surfacing
D. Underground drainage
Answer: Interior wall and ceiling surfacing
Rationale: Gypsum board is primarily used to create
smooth interior wall and ceiling surfaces and can also
provide fire-resistance and sound-control properties.
4. Which gypsum board type is commonly used in areas
subject to elevated moisture?
A. Standard white gypsum board
B. Moisture-resistant gypsum board
C. Exterior plywood only
D. Fiberboard insulation
Answer: Moisture-resistant gypsum board
Rationale: Moisture-resistant gypsum board is designed
for locations where intermittent moisture exposure is
expected, although it is not a substitute for
waterproofing in wet areas.
5. What is the primary purpose of Type X gypsum board?
A. Increase flexibility
B. Reduce board weight
C. Provide enhanced fire resistance
D. Improve exterior waterproofing
Answer: Provide enhanced fire resistance
Rationale: Type X gypsum board contains additives and
has characteristics that allow assemblies using it to
achieve specified fire-resistance ratings when properly
constructed.
6. What is the purpose of tapered edges on gypsum board?
,A. Increase board thickness
B. Provide a recessed area for joint treatment
C. Eliminate the need for fasteners
D. Make the board waterproof
Answer: Provide a recessed area for joint treatment
Rationale: Tapered edges allow joint compound and
tape to be recessed so properly finished joints can
produce a relatively flat surface.
7. Which material is normally used to reinforce a gypsum
board joint?
A. Roofing felt
B. Plastic flashing
C. Joint tape
D. Metal roofing
Answer: Joint tape
Rationale: Joint tape reinforces the joint and helps
prevent cracking when properly embedded in joint
compound.
8. What is the primary purpose of drywall joint compound?
A. Waterproof the foundation
B. Replace framing members
C. Treat joints, fastener heads, and surface
imperfections
D. Bond concrete footings
Answer: Treat joints, fastener heads, and surface
imperfections
Rationale: Joint compound is used with tape and other
finishing materials to produce smooth gypsum board
surfaces.
9. Which tool is commonly used to apply and smooth joint
compound?
, A. Pipe wrench
B. Framing hammer
C. Taping knife
D. Bolt cutter
Answer: Taping knife
Rationale: Taping knives are designed to spread,
feather, and smooth joint compound over joints and
fastener heads.
10. What is the main purpose of a drywall screw?
A. Seal a plumbing fitting
B. Fasten gypsum board to framing
C. Reinforce concrete
D. Install roofing membrane
Answer: Fasten gypsum board to framing
Rationale: Drywall screws are specifically designed to
secure gypsum board to wood or metal framing while
minimizing damage to the board face.
11. Why should gypsum board fasteners be installed at
the proper depth?
A. To make the board thicker
B. To eliminate framing
C. To secure the board without damaging the face paper
excessively
D. To increase moisture absorption
Answer: To secure the board without damaging the face
paper excessively
Rationale: Overdriven fasteners can break through the
face paper and reduce holding strength, while
underdriven fasteners can interfere with finishing.
12. What is a “fastener pop” in finished drywall?
A. A type of plaster texture
B. A fastener head that becomes visible or pushes
Plaster Contractor Practice Exam
| Questions, Verified Answers &
Detailed Rationales | Complete
Contractor License Exam Prep
Study Guide | Updated 2026
1. What is the primary raw material used to manufacture
conventional gypsum plaster?
A. Portland cement
B. Hydrated lime
C. Gypsum
D. Silica sand
Answer: Gypsum
Rationale: Gypsum is calcium sulfate dihydrate and is
the principal mineral used to manufacture gypsum
plaster and gypsum board products.
2. What happens when calcined gypsum is mixed with water?
A. It becomes permanently flexible
B. It rehydrates and sets into a hardened gypsum
material
C. It changes into Portland cement
D. It becomes waterproof
Answer: It rehydrates and sets into a hardened gypsum
material
Rationale: Calcined gypsum reacts with water and
recrystallizes as gypsum, producing the setting and
hardening characteristics of gypsum plaster.
, 3. What is the primary purpose of gypsum wallboard?
A. Structural foundation support
B. Exterior roofing
C. Interior wall and ceiling surfacing
D. Underground drainage
Answer: Interior wall and ceiling surfacing
Rationale: Gypsum board is primarily used to create
smooth interior wall and ceiling surfaces and can also
provide fire-resistance and sound-control properties.
4. Which gypsum board type is commonly used in areas
subject to elevated moisture?
A. Standard white gypsum board
B. Moisture-resistant gypsum board
C. Exterior plywood only
D. Fiberboard insulation
Answer: Moisture-resistant gypsum board
Rationale: Moisture-resistant gypsum board is designed
for locations where intermittent moisture exposure is
expected, although it is not a substitute for
waterproofing in wet areas.
5. What is the primary purpose of Type X gypsum board?
A. Increase flexibility
B. Reduce board weight
C. Provide enhanced fire resistance
D. Improve exterior waterproofing
Answer: Provide enhanced fire resistance
Rationale: Type X gypsum board contains additives and
has characteristics that allow assemblies using it to
achieve specified fire-resistance ratings when properly
constructed.
6. What is the purpose of tapered edges on gypsum board?
,A. Increase board thickness
B. Provide a recessed area for joint treatment
C. Eliminate the need for fasteners
D. Make the board waterproof
Answer: Provide a recessed area for joint treatment
Rationale: Tapered edges allow joint compound and
tape to be recessed so properly finished joints can
produce a relatively flat surface.
7. Which material is normally used to reinforce a gypsum
board joint?
A. Roofing felt
B. Plastic flashing
C. Joint tape
D. Metal roofing
Answer: Joint tape
Rationale: Joint tape reinforces the joint and helps
prevent cracking when properly embedded in joint
compound.
8. What is the primary purpose of drywall joint compound?
A. Waterproof the foundation
B. Replace framing members
C. Treat joints, fastener heads, and surface
imperfections
D. Bond concrete footings
Answer: Treat joints, fastener heads, and surface
imperfections
Rationale: Joint compound is used with tape and other
finishing materials to produce smooth gypsum board
surfaces.
9. Which tool is commonly used to apply and smooth joint
compound?
, A. Pipe wrench
B. Framing hammer
C. Taping knife
D. Bolt cutter
Answer: Taping knife
Rationale: Taping knives are designed to spread,
feather, and smooth joint compound over joints and
fastener heads.
10. What is the main purpose of a drywall screw?
A. Seal a plumbing fitting
B. Fasten gypsum board to framing
C. Reinforce concrete
D. Install roofing membrane
Answer: Fasten gypsum board to framing
Rationale: Drywall screws are specifically designed to
secure gypsum board to wood or metal framing while
minimizing damage to the board face.
11. Why should gypsum board fasteners be installed at
the proper depth?
A. To make the board thicker
B. To eliminate framing
C. To secure the board without damaging the face paper
excessively
D. To increase moisture absorption
Answer: To secure the board without damaging the face
paper excessively
Rationale: Overdriven fasteners can break through the
face paper and reduce holding strength, while
underdriven fasteners can interfere with finishing.
12. What is a “fastener pop” in finished drywall?
A. A type of plaster texture
B. A fastener head that becomes visible or pushes
