CO Overhead Door Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the standard residential garage door height?
A) 6 feet
B) 7 feet
C) 8 feet
D) 9 feet
B) 7 feet
Rationale: Most residential garage doors are manufactured with a
standard height of 7 feet to accommodate typical vehicle heights.
2. Which type of spring is most commonly used on modern garage doors?
A) Torsion spring
B) Extension spring
C) Helical spring
D) Coil spring
A) Torsion spring
Rationale: Torsion springs provide smoother operation and are safer
than extension springs, which are less common on modern
installations.
3. What is the primary purpose of a garage door opener's limit switch?
A) Adjust motor speed
B) Set the open/close travel points
C) Prevent electrical overload
D) Lock the door automatically
B) Set the open/close travel points
Rationale: Limit switches ensure the door stops at fully open or
closed positions, preventing damage or injury.
,4. Which material is most commonly used for residential overhead doors?
A) Wood
B) Aluminum
C) Steel
D) Fiberglass
C) Steel
Rationale: Steel is durable, low maintenance, and cost-effective for
residential doors, making it the most common material.
5. What safety feature must be present on all garage door openers
manufactured after 1993?
A) Motion detector
B) Photoelectric sensors
C) Automatic lock
D) Timer-to-close
B) Photoelectric sensors
Rationale: Photoelectric sensors detect objects in the door path and
prevent closing to reduce injury risk.
6. Which component absorbs the energy of the door’s motion to reduce
impact?
A) Cable drum
B) Spring
C) Shock absorber
D) Safety sensor
C) Shock absorber
Rationale: Shock absorbers, often part of hydraulic or dampening
systems, reduce wear and risk of injury.
7. What is the recommended minimum headroom for a standard torsion
spring garage door?
A) 10 inches
B) 12 inches
C) 14 inches
D) 16 inches
B) 12 inches
Rationale: Minimum headroom ensures proper installation and safe
operation of torsion spring systems.
8. How should a damaged garage door cable be replaced?
A) Disconnect power and carefully unwind spring tension
, B) Cut cable while door is loaded
C) Replace without tensioning the spring
D) Only replace the spring, cable not needed
A) Disconnect power and carefully unwind spring tension
Rationale: Garage door cables are under extreme tension; safe
replacement requires de-energizing and controlling spring tension.
9. What is the purpose of bottom door brackets?
A) Attach motor to door
B) Secure the door to the floor
C) Connect door panels to the lifting cables
D) Provide decorative finishes
C) Connect door panels to the lifting cables
Rationale: Bottom brackets secure the lifting cables and rollers to the
bottom of the door, ensuring smooth movement.
10. What is the maximum door width for a standard single-car
residential garage door?
A) 7 feet
B) 8 feet
C) 9 feet
D) 10 feet
C) 9 feet
Rationale: Standard single-car doors range from 8–9 feet wide, with
9 feet being most common.
11. Which of the following is a common sign of a worn torsion
spring?
A) Door closes too fast
B) Door opens slowly
C) Door shakes or jerks
D) All of the above
D) All of the above
Rationale: Worn springs affect door balance and smooth operation,
causing slow opening, fast closing, and jerky motion.
12. What type of fastener is recommended for attaching metal tracks
to wooden framing?
A) Wood screws
B) Lag bolts
C) Nails
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the standard residential garage door height?
A) 6 feet
B) 7 feet
C) 8 feet
D) 9 feet
B) 7 feet
Rationale: Most residential garage doors are manufactured with a
standard height of 7 feet to accommodate typical vehicle heights.
2. Which type of spring is most commonly used on modern garage doors?
A) Torsion spring
B) Extension spring
C) Helical spring
D) Coil spring
A) Torsion spring
Rationale: Torsion springs provide smoother operation and are safer
than extension springs, which are less common on modern
installations.
3. What is the primary purpose of a garage door opener's limit switch?
A) Adjust motor speed
B) Set the open/close travel points
C) Prevent electrical overload
D) Lock the door automatically
B) Set the open/close travel points
Rationale: Limit switches ensure the door stops at fully open or
closed positions, preventing damage or injury.
,4. Which material is most commonly used for residential overhead doors?
A) Wood
B) Aluminum
C) Steel
D) Fiberglass
C) Steel
Rationale: Steel is durable, low maintenance, and cost-effective for
residential doors, making it the most common material.
5. What safety feature must be present on all garage door openers
manufactured after 1993?
A) Motion detector
B) Photoelectric sensors
C) Automatic lock
D) Timer-to-close
B) Photoelectric sensors
Rationale: Photoelectric sensors detect objects in the door path and
prevent closing to reduce injury risk.
6. Which component absorbs the energy of the door’s motion to reduce
impact?
A) Cable drum
B) Spring
C) Shock absorber
D) Safety sensor
C) Shock absorber
Rationale: Shock absorbers, often part of hydraulic or dampening
systems, reduce wear and risk of injury.
7. What is the recommended minimum headroom for a standard torsion
spring garage door?
A) 10 inches
B) 12 inches
C) 14 inches
D) 16 inches
B) 12 inches
Rationale: Minimum headroom ensures proper installation and safe
operation of torsion spring systems.
8. How should a damaged garage door cable be replaced?
A) Disconnect power and carefully unwind spring tension
, B) Cut cable while door is loaded
C) Replace without tensioning the spring
D) Only replace the spring, cable not needed
A) Disconnect power and carefully unwind spring tension
Rationale: Garage door cables are under extreme tension; safe
replacement requires de-energizing and controlling spring tension.
9. What is the purpose of bottom door brackets?
A) Attach motor to door
B) Secure the door to the floor
C) Connect door panels to the lifting cables
D) Provide decorative finishes
C) Connect door panels to the lifting cables
Rationale: Bottom brackets secure the lifting cables and rollers to the
bottom of the door, ensuring smooth movement.
10. What is the maximum door width for a standard single-car
residential garage door?
A) 7 feet
B) 8 feet
C) 9 feet
D) 10 feet
C) 9 feet
Rationale: Standard single-car doors range from 8–9 feet wide, with
9 feet being most common.
11. Which of the following is a common sign of a worn torsion
spring?
A) Door closes too fast
B) Door opens slowly
C) Door shakes or jerks
D) All of the above
D) All of the above
Rationale: Worn springs affect door balance and smooth operation,
causing slow opening, fast closing, and jerky motion.
12. What type of fastener is recommended for attaching metal tracks
to wooden framing?
A) Wood screws
B) Lag bolts
C) Nails
