Florida Sheet Metal Contractor Licensing
Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This document presents a comprehensive examination for the Florida Sheet Metal
Contractor Licensing Exam with a structure consisting of 2 parts. Part 1 covers Sheet Metal
Trade Knowledge, including HVAC duct fabrication, architectural sheet metal, welding,
hangers, supports, roofing, and safety regulations (OSHA, building codes). Part 2 addresses
Business and Finance, focusing on Florida lien law, contract management, accounting, cost
control, licensing requirements, and risk management.
PART 1 – SHEET METAL TRADE KNOWLEDGE
QUESTION 1
Which of the following is the minimum thickness for galvanized steel used in a
residential supply duct with a longest side of 18 inches?
A) 26 gauge
B) 24 gauge
C) 22 gauge
D) 20 gauge
CORRECT ANSWER: B
EXPERT RATIONALE: SMACNA standards require 24 gauge galvanized steel for
residential supply ducts with longest side up to 18 inches. Thinner gauges risk excessive
flexing and noise.
,QUESTION 2
When installing flexible duct in an attic, what is the maximum sag allowance per foot
between supports?
A) 0 inches (no sag allowed)
B) 0.5 inch per foot
C) 1 inch per foot
D) 2 inches per foot
CORRECT ANSWER: B
EXPERT RATIONALE: Sag beyond 0.5 inch per foot creates low points where
condensate and debris collect, reducing airflow and promoting mold growth.
QUESTION 3
What is the primary purpose of a turning vane in a sheet metal elbow?
A) Reduce noise only
B) Increase static pressure
C) Reduce turbulence and pressure drop
D) Allow for thermal expansion
CORRECT ANSWER: C
EXPERT RATIONALE: Turning vanes streamline airflow around bends, reducing
turbulence and pressure loss by up to 50% compared to a bare elbow.
QUESTION 4
According to OSHA 1926.352, when welding or cutting near combustible materials, what
is the minimum distance for fire watcher presence after the work stops?
A) 15 minutes
B) 30 minutes
,C) 45 minutes
D) 60 minutes
CORRECT ANSWER: B
EXPERT RATIONALE: A fire watcher must remain for at least 30 minutes after
welding/cutting to detect smoldering fires that may ignite later.
QUESTION 5
For a rectangular duct with a ductile liner, what is the minimum clearance required
between the liner and a fire damper?
A) 0 inches
B) 2 inches
C) 6 inches
D) 12 inches
CORRECT ANSWER: C
EXPERT RATIONALE: Liner must stop at least 6 inches before a fire damper to prevent
the liner from obstructing damper closure during a fire.
QUESTION 6
What is the maximum allowable leakage class for a medium-pressure supply duct (2–3
in. w.g.) per SMACNA?
A) Class 3
B) Class 6
C) Class 12
D) Class 24
CORRECT ANSWER: C
, EXPERT RATIONALE: SMACNA specifies Class 12 leakage for medium-pressure ducts;
higher classes allow excessive leakage that reduces system efficiency.
QUESTION 7
In Florida, which code governs the seismic requirements for sheet metal hangers and
supports?
A) Florida Building Code – Residential only
B) Florida Building Code – Mechanical (adopting ASCE 7)
C) NFPA 90A only
D) ASHRAE 15
CORRECT ANSWER: B
EXPERT RATIONALE: The Florida Building Code, Mechanical volume, references ASCE 7
for seismic restraints, even though Florida is low seismicity; certain structures still require
bracing.
QUESTION 8
When brazing copper tubing for a refrigerant line set, what is the proper gas to use with
oxy-acetylene for most sheet metal HVAC work?
A) Acetylene only
B) Propane only
C) Nitrogen as a purge gas
D) Argon as a shield gas
CORRECT ANSWER: C
EXPERT RATIONALE: Nitrogen purge prevents oxidation inside copper lines; oxygen
and acetylene provide the heat, but nitrogen is the purge gas to avoid scale formation.
Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This document presents a comprehensive examination for the Florida Sheet Metal
Contractor Licensing Exam with a structure consisting of 2 parts. Part 1 covers Sheet Metal
Trade Knowledge, including HVAC duct fabrication, architectural sheet metal, welding,
hangers, supports, roofing, and safety regulations (OSHA, building codes). Part 2 addresses
Business and Finance, focusing on Florida lien law, contract management, accounting, cost
control, licensing requirements, and risk management.
PART 1 – SHEET METAL TRADE KNOWLEDGE
QUESTION 1
Which of the following is the minimum thickness for galvanized steel used in a
residential supply duct with a longest side of 18 inches?
A) 26 gauge
B) 24 gauge
C) 22 gauge
D) 20 gauge
CORRECT ANSWER: B
EXPERT RATIONALE: SMACNA standards require 24 gauge galvanized steel for
residential supply ducts with longest side up to 18 inches. Thinner gauges risk excessive
flexing and noise.
,QUESTION 2
When installing flexible duct in an attic, what is the maximum sag allowance per foot
between supports?
A) 0 inches (no sag allowed)
B) 0.5 inch per foot
C) 1 inch per foot
D) 2 inches per foot
CORRECT ANSWER: B
EXPERT RATIONALE: Sag beyond 0.5 inch per foot creates low points where
condensate and debris collect, reducing airflow and promoting mold growth.
QUESTION 3
What is the primary purpose of a turning vane in a sheet metal elbow?
A) Reduce noise only
B) Increase static pressure
C) Reduce turbulence and pressure drop
D) Allow for thermal expansion
CORRECT ANSWER: C
EXPERT RATIONALE: Turning vanes streamline airflow around bends, reducing
turbulence and pressure loss by up to 50% compared to a bare elbow.
QUESTION 4
According to OSHA 1926.352, when welding or cutting near combustible materials, what
is the minimum distance for fire watcher presence after the work stops?
A) 15 minutes
B) 30 minutes
,C) 45 minutes
D) 60 minutes
CORRECT ANSWER: B
EXPERT RATIONALE: A fire watcher must remain for at least 30 minutes after
welding/cutting to detect smoldering fires that may ignite later.
QUESTION 5
For a rectangular duct with a ductile liner, what is the minimum clearance required
between the liner and a fire damper?
A) 0 inches
B) 2 inches
C) 6 inches
D) 12 inches
CORRECT ANSWER: C
EXPERT RATIONALE: Liner must stop at least 6 inches before a fire damper to prevent
the liner from obstructing damper closure during a fire.
QUESTION 6
What is the maximum allowable leakage class for a medium-pressure supply duct (2–3
in. w.g.) per SMACNA?
A) Class 3
B) Class 6
C) Class 12
D) Class 24
CORRECT ANSWER: C
, EXPERT RATIONALE: SMACNA specifies Class 12 leakage for medium-pressure ducts;
higher classes allow excessive leakage that reduces system efficiency.
QUESTION 7
In Florida, which code governs the seismic requirements for sheet metal hangers and
supports?
A) Florida Building Code – Residential only
B) Florida Building Code – Mechanical (adopting ASCE 7)
C) NFPA 90A only
D) ASHRAE 15
CORRECT ANSWER: B
EXPERT RATIONALE: The Florida Building Code, Mechanical volume, references ASCE 7
for seismic restraints, even though Florida is low seismicity; certain structures still require
bracing.
QUESTION 8
When brazing copper tubing for a refrigerant line set, what is the proper gas to use with
oxy-acetylene for most sheet metal HVAC work?
A) Acetylene only
B) Propane only
C) Nitrogen as a purge gas
D) Argon as a shield gas
CORRECT ANSWER: C
EXPERT RATIONALE: Nitrogen purge prevents oxidation inside copper lines; oxygen
and acetylene provide the heat, but nitrogen is the purge gas to avoid scale formation.
