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C 39 roofing trade test 1 and test 2 (complete tests)
Newest Exam Preparation With Complete Questions
And Correct Answers With Rationales Already
Graded A+Brand New Version!!
QUESTION 1
A span rating of _______ means that a plywood panel may be used for
roof decking over supports spaced 32 inches o.c. or for subflooring over
supports spaced 16 inches o.c.
A) 16/32
B) 32/16
C) 32/48
D) 48/32
Answer: B) 32/16
Explanation: The span rating system for plywood uses two numbers
separated by a slash. The first number indicates the maximum spacing
for roof decking applications, and the second indicates the maximum
spacing for subflooring applications. A 32/16 rating means the panel is
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suitable for roof decking over supports at 32 inches on center and for
subflooring over supports at 16 inches on center. This rating system is
critical for ensuring structural integrity and proper load distribution in
roofing applications.
QUESTION 2
On plywood decks not covered with insulation, a base ply should be
_______ to serve as the base ply of the roof membrane.
A) Nailed with smooth shank nails
B) Glued with construction adhesive
C) Attached with annular-threaded nails
D) Stapled with heavy-duty staples
Answer: C) Attached with annular-threaded nails
Explanation: Annular-threaded nails provide superior holding power in
plywood decking due to their ringed shank design. When insulation is
not present to protect the membrane, the base ply must be securely
fastened to withstand wind uplift and other stresses. The annular
threads create mechanical interlock with the wood fibers, preventing
the nails from backing out over time.
QUESTION 3
The choice of membrane type for a roof is frequently determined by:
A) Building height and appearance
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B) Geographical location and climate
C) Cost of materials only
D) Availability of labor
Answer: B) Geographical location and climate
Explanation: Different membrane types perform better under specific
climatic conditions. For example, in regions with extreme temperature
fluctuations, membranes with higher thermal stability are required. In
areas with high UV exposure, reflective or UV-resistant membranes are
preferred. Geographic location influences factors such as snow load,
wind exposure, temperature extremes, and precipitation patterns, all of
which affect membrane selection.
QUESTION 4
Technical information useful in the selection of roof membranes is
provided by the:
A) American Society of Civil Engineers
B) National Bureau of Standards
C) Environmental Protection Agency
D) Occupational Safety and Health Administration
Answer: B) National Bureau of Standards
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Explanation: The National Bureau of Standards (now NIST) provides
technical data and standards related to building materials, including
roofing membranes. Their research establishes performance criteria,
testing methods, and material specifications that guide the selection of
appropriate roofing systems.
QUESTION 5
On low-sloped roofs, felt should be laid _______ the flow of water,
beginning at _______ points in the deck.
A) Parallel to ... high
B) Perpendicular to ... low
C) Parallel to ... low
D) Perpendicular to ... high
Answer: B) Perpendicular to ... low
Explanation: Laying felt perpendicular to the direction of water flow
helps prevent water from traveling along the seams. Starting at the low
points ensures proper drainage and prevents water from ponding
beneath the felt. This installation technique is fundamental to proper
low-slope roofing practice.
QUESTION 6
On slopes over 2 inches per foot, felt should be laid:
A) Perpendicular to the slope
C 39 roofing trade test 1 and test 2 (complete tests)
Newest Exam Preparation With Complete Questions
And Correct Answers With Rationales Already
Graded A+Brand New Version!!
QUESTION 1
A span rating of _______ means that a plywood panel may be used for
roof decking over supports spaced 32 inches o.c. or for subflooring over
supports spaced 16 inches o.c.
A) 16/32
B) 32/16
C) 32/48
D) 48/32
Answer: B) 32/16
Explanation: The span rating system for plywood uses two numbers
separated by a slash. The first number indicates the maximum spacing
for roof decking applications, and the second indicates the maximum
spacing for subflooring applications. A 32/16 rating means the panel is
,2|Page
suitable for roof decking over supports at 32 inches on center and for
subflooring over supports at 16 inches on center. This rating system is
critical for ensuring structural integrity and proper load distribution in
roofing applications.
QUESTION 2
On plywood decks not covered with insulation, a base ply should be
_______ to serve as the base ply of the roof membrane.
A) Nailed with smooth shank nails
B) Glued with construction adhesive
C) Attached with annular-threaded nails
D) Stapled with heavy-duty staples
Answer: C) Attached with annular-threaded nails
Explanation: Annular-threaded nails provide superior holding power in
plywood decking due to their ringed shank design. When insulation is
not present to protect the membrane, the base ply must be securely
fastened to withstand wind uplift and other stresses. The annular
threads create mechanical interlock with the wood fibers, preventing
the nails from backing out over time.
QUESTION 3
The choice of membrane type for a roof is frequently determined by:
A) Building height and appearance
,3|Page
B) Geographical location and climate
C) Cost of materials only
D) Availability of labor
Answer: B) Geographical location and climate
Explanation: Different membrane types perform better under specific
climatic conditions. For example, in regions with extreme temperature
fluctuations, membranes with higher thermal stability are required. In
areas with high UV exposure, reflective or UV-resistant membranes are
preferred. Geographic location influences factors such as snow load,
wind exposure, temperature extremes, and precipitation patterns, all of
which affect membrane selection.
QUESTION 4
Technical information useful in the selection of roof membranes is
provided by the:
A) American Society of Civil Engineers
B) National Bureau of Standards
C) Environmental Protection Agency
D) Occupational Safety and Health Administration
Answer: B) National Bureau of Standards
, 4|Page
Explanation: The National Bureau of Standards (now NIST) provides
technical data and standards related to building materials, including
roofing membranes. Their research establishes performance criteria,
testing methods, and material specifications that guide the selection of
appropriate roofing systems.
QUESTION 5
On low-sloped roofs, felt should be laid _______ the flow of water,
beginning at _______ points in the deck.
A) Parallel to ... high
B) Perpendicular to ... low
C) Parallel to ... low
D) Perpendicular to ... high
Answer: B) Perpendicular to ... low
Explanation: Laying felt perpendicular to the direction of water flow
helps prevent water from traveling along the seams. Starting at the low
points ensures proper drainage and prevents water from ponding
beneath the felt. This installation technique is fundamental to proper
low-slope roofing practice.
QUESTION 6
On slopes over 2 inches per foot, felt should be laid:
A) Perpendicular to the slope
