CONNECTICUT (CT) SM-1 LIMITED SHEET METAL CONTRACTOR
EXAM COMPLETE QUESTIONS AND WELL-EXPLAINED ANSWERS
1. Sheet metal used in HVAC ductwork is most commonly made from:
A. Copper
B. Aluminum
C. Galvanized steel
D. Brass
Answer: C. Galvanized steel
Explanation: Galvanized sheet steel is the standard material for HVAC ductwork
due to its durability, corrosion resistance, and cost-effectiveness.
2. The Connecticut SM-1 license authorizes work in:
A. Electrical wiring
B. Sheet metal work for HVAC systems
C. Masonry construction
D. Plumbing installations
Answer: B. Sheet metal work for HVAC systems
Explanation: The SM-1 Limited Sheet Metal license covers fabrication,
installation, erection, and repair of sheet metal for HVAC systems.
3. According to SMACNA standards, the maximum transverse joint spacing
for rectangular ducts is typically:
A. 6 ft
B. 8 ft
C. 10 ft
D. 12 ft
Answer: C. 10 ft
Explanation: Per SMACNA, joints in rectangular ducts are generally spaced at a
maximum of 10 ft to ensure structural integrity.
,4. Which code governs HVAC duct construction in Connecticut?
A. International Building Code (IBC)
B. Connecticut Mechanical Code
C. National Fire Protection Association (NFPA) 70
D. OSHA Construction Standards
Answer: B. Connecticut Mechanical Code
Explanation: The Connecticut Mechanical Code regulates HVAC system design,
installation, and sheet metal work.
5. When installing ducts in a fire-rated assembly, which code is most
relevant?
A. NFPA 70
B. NFPA 90A
C. OSHA 1926
D. Connecticut Building Code
Answer: B. NFPA 90A
Explanation: NFPA 90A governs installation of HVAC systems in air distribution
systems, particularly in fire-rated assemblies.
6. What gauge sheet metal is typically used for residential supply air ducts
under 12 inches?
A. 30 gauge
B. 28 gauge
C. 26 gauge
D. 24 gauge
Answer: C. 26 gauge
Explanation: SMACNA standards specify 26-gauge galvanized steel for ducts
under 12 inches in residential installations.
7. A Pittsburgh lock seam is commonly used for:
A. Electrical conduit joints
B. Plumbing fittings
C. Sheet metal duct longitudinal seams
D. Roofing shingles
,Answer: C. Sheet metal duct longitudinal seams
Explanation: The Pittsburgh lock seam is a standard method for connecting
sheet metal duct edges.
8. Flexible ductwork must be supported at least every:
A. 2 ft
B. 4 ft
C. 6 ft
D. 8 ft
Answer: B. 4 ft
Explanation: Flexible ducting must be supported at intervals of 4 ft or less to
prevent sagging and airflow restriction.
9. Which tool is primarily used to create bends in sheet metal?
A. Snips
B. Brake
C. Shear
D. Notcher
Answer: B. Brake
Explanation: A sheet metal brake is used to bend sheet metal to precise angles.
10. In Connecticut, the minimum duct clearance from combustible materials
for warm air ducts is usually:
A. 0 inches
B. 1 inch
C. 2 inches
D. 3 inches
Answer: B. 1 inch
Explanation: Mechanical codes require at least 1 inch clearance from ducts to
combustible construction unless otherwise protected.
11. The abbreviation “CFM” in duct design stands for:
A. Cubic Feet per Meter
, B. Cubic Feet per Minute
C. Cooling Factor Measurement
D. Cubic Flow Mass
Answer: B. Cubic Feet per Minute
Explanation: CFM measures airflow volume delivered by duct systems.
12. When fabricating rectangular duct, which dimension is considered
“width”?
A. The longer side
B. The shorter side
C. The diagonal
D. Either side
Answer: B. The shorter side
Explanation: In HVAC sheet metal practice, width is the shorter dimension, and
height is the longer dimension of rectangular duct.
13. Sealant used in duct joints must be:
A. Non-hardening
B. Flammable
C. Non-toxic, fire-resistant, and durable
D. Made of asphalt
Answer: C. Non-toxic, fire-resistant, and durable
Explanation: Duct sealants must comply with fire safety and durability
standards.
14. Slip and drive connectors are used for:
A. Round duct connections
B. Rectangular duct transverse joints
C. Welding reinforcement
D. Attaching duct hangers
Answer: B. Rectangular duct transverse joints
Explanation: Slip and drive connections are standard for joining rectangular
ducts end-to-end.
EXAM COMPLETE QUESTIONS AND WELL-EXPLAINED ANSWERS
1. Sheet metal used in HVAC ductwork is most commonly made from:
A. Copper
B. Aluminum
C. Galvanized steel
D. Brass
Answer: C. Galvanized steel
Explanation: Galvanized sheet steel is the standard material for HVAC ductwork
due to its durability, corrosion resistance, and cost-effectiveness.
2. The Connecticut SM-1 license authorizes work in:
A. Electrical wiring
B. Sheet metal work for HVAC systems
C. Masonry construction
D. Plumbing installations
Answer: B. Sheet metal work for HVAC systems
Explanation: The SM-1 Limited Sheet Metal license covers fabrication,
installation, erection, and repair of sheet metal for HVAC systems.
3. According to SMACNA standards, the maximum transverse joint spacing
for rectangular ducts is typically:
A. 6 ft
B. 8 ft
C. 10 ft
D. 12 ft
Answer: C. 10 ft
Explanation: Per SMACNA, joints in rectangular ducts are generally spaced at a
maximum of 10 ft to ensure structural integrity.
,4. Which code governs HVAC duct construction in Connecticut?
A. International Building Code (IBC)
B. Connecticut Mechanical Code
C. National Fire Protection Association (NFPA) 70
D. OSHA Construction Standards
Answer: B. Connecticut Mechanical Code
Explanation: The Connecticut Mechanical Code regulates HVAC system design,
installation, and sheet metal work.
5. When installing ducts in a fire-rated assembly, which code is most
relevant?
A. NFPA 70
B. NFPA 90A
C. OSHA 1926
D. Connecticut Building Code
Answer: B. NFPA 90A
Explanation: NFPA 90A governs installation of HVAC systems in air distribution
systems, particularly in fire-rated assemblies.
6. What gauge sheet metal is typically used for residential supply air ducts
under 12 inches?
A. 30 gauge
B. 28 gauge
C. 26 gauge
D. 24 gauge
Answer: C. 26 gauge
Explanation: SMACNA standards specify 26-gauge galvanized steel for ducts
under 12 inches in residential installations.
7. A Pittsburgh lock seam is commonly used for:
A. Electrical conduit joints
B. Plumbing fittings
C. Sheet metal duct longitudinal seams
D. Roofing shingles
,Answer: C. Sheet metal duct longitudinal seams
Explanation: The Pittsburgh lock seam is a standard method for connecting
sheet metal duct edges.
8. Flexible ductwork must be supported at least every:
A. 2 ft
B. 4 ft
C. 6 ft
D. 8 ft
Answer: B. 4 ft
Explanation: Flexible ducting must be supported at intervals of 4 ft or less to
prevent sagging and airflow restriction.
9. Which tool is primarily used to create bends in sheet metal?
A. Snips
B. Brake
C. Shear
D. Notcher
Answer: B. Brake
Explanation: A sheet metal brake is used to bend sheet metal to precise angles.
10. In Connecticut, the minimum duct clearance from combustible materials
for warm air ducts is usually:
A. 0 inches
B. 1 inch
C. 2 inches
D. 3 inches
Answer: B. 1 inch
Explanation: Mechanical codes require at least 1 inch clearance from ducts to
combustible construction unless otherwise protected.
11. The abbreviation “CFM” in duct design stands for:
A. Cubic Feet per Meter
, B. Cubic Feet per Minute
C. Cooling Factor Measurement
D. Cubic Flow Mass
Answer: B. Cubic Feet per Minute
Explanation: CFM measures airflow volume delivered by duct systems.
12. When fabricating rectangular duct, which dimension is considered
“width”?
A. The longer side
B. The shorter side
C. The diagonal
D. Either side
Answer: B. The shorter side
Explanation: In HVAC sheet metal practice, width is the shorter dimension, and
height is the longer dimension of rectangular duct.
13. Sealant used in duct joints must be:
A. Non-hardening
B. Flammable
C. Non-toxic, fire-resistant, and durable
D. Made of asphalt
Answer: C. Non-toxic, fire-resistant, and durable
Explanation: Duct sealants must comply with fire safety and durability
standards.
14. Slip and drive connectors are used for:
A. Round duct connections
B. Rectangular duct transverse joints
C. Welding reinforcement
D. Attaching duct hangers
Answer: B. Rectangular duct transverse joints
Explanation: Slip and drive connections are standard for joining rectangular
ducts end-to-end.
