CO Masonry Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. The primary purpose of a masonry footing is to:
A. Prevent mortar shrinkage
B. Support and distribute structural loads
C. Increase building height
D. Provide insulation
Answer: B
Rationale: Footings spread building loads over a wider soil area to ensure
stability and prevent settlement.
2. Which material is most commonly used for constructing load-bearing
masonry walls?
A. Glass blocks
B. Adobe bricks
C. Concrete masonry units (CMUs)
D. Foam blocks
Rationale: CMUs offer high compressive strength and are widely used in
load-bearing applications.
3. What is the ideal moisture content of bricks before laying?
,A. Completely dry
B. Slightly damp
C. Fully soaked
D. Saturated for 24 hours
Rationale: Damp bricks prevent premature moisture absorption from the
mortar, ensuring proper bond strength.
4. Mortar Type S is primarily used for:
A. Interior non-load-bearing walls
B. Chimneys
C. Exterior load-bearing walls and below-grade applications
D. Decorative veneers only
Rationale: Type S provides high compressive strength and flexibility for
structural and below-grade use.
5. Which tool is essential for striking masonry joints?
A. Brick hammer
B. Trowel
C. Jointer
D. Level
Rationale: A jointer shapes and compresses mortar joints, improving
durability and appearance.
6. The term “wythe” refers to:
A. Mortar type
B. A single vertical layer of masonry units
C. Reinforcement bar spacing
D. Grout consolidation method
Rationale: A wythe is a continuous vertical section of masonry one unit
thick.
7. What is the typical thickness of a standard CMU?
A. 2 inches
B. 6 inches
C. 8 inches
, D. 12 inches
Rationale: Standard CMUs commonly measure 8x8x16 inches in nominal
size.
8. Flashing in masonry walls prevents:
A. Heat loss
B. Moisture penetration
C. Mortar shrinkage
D. Thermal expansion
Rationale: Flashing diverts water out of the wall cavity, reducing moisture
damage.
9. A control joint in masonry walls is used to:
A. Add reinforcement
B. Control cracking due to thermal and moisture movement
C. Increase wall strength
D. Provide ventilation
Rationale: Control joints absorb expansion and contraction to prevent
random cracking.
10. The main ingredient responsible for mortar strength is:
A. Sand
B. Water
C. Cement
D. Additives
Rationale: Cement hydrates and binds the sand into a strong matrix.
11. What is the minimum recommended lap for vertical reinforcement
splices in masonry?
A. 10 bar diameters
B. 20 bar diameters
C. 40 bar diameters
D. 60 bar diameters
Rationale: A 40-diameter lap ensures proper load transfer between
reinforcing bars.
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. The primary purpose of a masonry footing is to:
A. Prevent mortar shrinkage
B. Support and distribute structural loads
C. Increase building height
D. Provide insulation
Answer: B
Rationale: Footings spread building loads over a wider soil area to ensure
stability and prevent settlement.
2. Which material is most commonly used for constructing load-bearing
masonry walls?
A. Glass blocks
B. Adobe bricks
C. Concrete masonry units (CMUs)
D. Foam blocks
Rationale: CMUs offer high compressive strength and are widely used in
load-bearing applications.
3. What is the ideal moisture content of bricks before laying?
,A. Completely dry
B. Slightly damp
C. Fully soaked
D. Saturated for 24 hours
Rationale: Damp bricks prevent premature moisture absorption from the
mortar, ensuring proper bond strength.
4. Mortar Type S is primarily used for:
A. Interior non-load-bearing walls
B. Chimneys
C. Exterior load-bearing walls and below-grade applications
D. Decorative veneers only
Rationale: Type S provides high compressive strength and flexibility for
structural and below-grade use.
5. Which tool is essential for striking masonry joints?
A. Brick hammer
B. Trowel
C. Jointer
D. Level
Rationale: A jointer shapes and compresses mortar joints, improving
durability and appearance.
6. The term “wythe” refers to:
A. Mortar type
B. A single vertical layer of masonry units
C. Reinforcement bar spacing
D. Grout consolidation method
Rationale: A wythe is a continuous vertical section of masonry one unit
thick.
7. What is the typical thickness of a standard CMU?
A. 2 inches
B. 6 inches
C. 8 inches
, D. 12 inches
Rationale: Standard CMUs commonly measure 8x8x16 inches in nominal
size.
8. Flashing in masonry walls prevents:
A. Heat loss
B. Moisture penetration
C. Mortar shrinkage
D. Thermal expansion
Rationale: Flashing diverts water out of the wall cavity, reducing moisture
damage.
9. A control joint in masonry walls is used to:
A. Add reinforcement
B. Control cracking due to thermal and moisture movement
C. Increase wall strength
D. Provide ventilation
Rationale: Control joints absorb expansion and contraction to prevent
random cracking.
10. The main ingredient responsible for mortar strength is:
A. Sand
B. Water
C. Cement
D. Additives
Rationale: Cement hydrates and binds the sand into a strong matrix.
11. What is the minimum recommended lap for vertical reinforcement
splices in masonry?
A. 10 bar diameters
B. 20 bar diameters
C. 40 bar diameters
D. 60 bar diameters
Rationale: A 40-diameter lap ensures proper load transfer between
reinforcing bars.
