Roofing
C-39 Roofing Trade Practice Test 1 Questions
and Answers UPDATED 2025
Composition flashing (base flashing) should be fastened with: -Correct Answer ✔One-
inch solid cap-head nails or
Nails driven theough tin disks
Pitch pockets or pitch boxes: -Correct Answer ✔Are not recommended because they
require extensive maintenance
Reinforced concrete can be used as a structural deck. Which of the following is a
correct statement? -Correct Answer ✔Some moisture will remain in concrete decks
even after the surface is dry
Roofing insulation and membranes must be protected from latent moisture in concrete
decks. In northern climates, this is usually accomplished with: -Correct Answer ✔A
vapor retarder or
A venting sheet
Steel decks should be at least _______ or heavier. -Correct Answer ✔22g
Insulation applied to steel roof decks before the roof membrane is installed should be
applied: -Correct Answer ✔In two separate layers where insulation thickness permits
The top flanges of a steel roof deck should be installed: -Correct Answer
✔Perpendicular to the roof slope
The maximum deflection allowed for a steel deck is: -Correct Answer ✔1/4" per 100 feet
If the steel decks must be spot-welded to structural steel, puddle welds _______ or
larger in diameter are recommended. They should be made on washers and spaced at
least _______ on center. -Correct Answer ✔1/2 inches ... 12 inches
If thermosetting insulation is used over structural decks, the density should be: -Correct
Answer ✔18 to 22 pounds per cubic foot
The correct density for thermosetting insulation is accomplished by: -Correct Answer
✔Compacting
Thermosetting insulation is compacted in two layers if the total thickness is greater than:
-Correct Answer ✔6 inches
Roofing
, Roofing
Thermosetting insulative fills must be protected from latent moisture in roof decks.
Which of the following procedures is recommended? -Correct Answer ✔Install base-ply
vapor barrier and
Install wood nailers at all perimeters and
Install wood nailers at all roof projections
What type of roof is recommended over thermosetting insulative fills -Correct Answer
✔Aggregate
A span rating of _______ means that a plywood panel may be used for roof decking
over supports spaced 32 inches o.c. or for sub flooring over supports spaced 16 inches
o.c. -Correct Answer ✔32/16
On plywood decks not covered with insulation, a base ply should be _______ to serve
as as the base ply of the roof membrane. -Correct Answer ✔Attached with annular-
threaded nails
The choice of membrane type for a roof is frequently determined by: -Correct Answer
✔Geographical location and
Climate
Technical information useful in the selection of roof membranes is provided by the: -
Correct Answer ✔National Bureau of Standards
On low-sloped roofs, felt should be laid _______ the flow of water, beginning at
_______ points in the deck. -Correct Answer ✔Perpendicular ... low
On slopes over 2 inches per foot, felt should be laid: -Correct Answer ✔Parallel to the
slopes
For asphalt roofs, treated wood nailers should be installed perpendicular to the slope
and on 20 - foot centers for slopes up to: -Correct Answer ✔3 inches per foot
A roofing contractor discovers damage done by other trades to a newly installed roof.
What should the roofing contractor do? -Correct Answer ✔Submit a written report to the
general contractor and/or the owner for any visible damage
When layers of felt are joined by hot-mopping, the process is most similar to: -Correct
Answer ✔Welding
Roofing
C-39 Roofing Trade Practice Test 1 Questions
and Answers UPDATED 2025
Composition flashing (base flashing) should be fastened with: -Correct Answer ✔One-
inch solid cap-head nails or
Nails driven theough tin disks
Pitch pockets or pitch boxes: -Correct Answer ✔Are not recommended because they
require extensive maintenance
Reinforced concrete can be used as a structural deck. Which of the following is a
correct statement? -Correct Answer ✔Some moisture will remain in concrete decks
even after the surface is dry
Roofing insulation and membranes must be protected from latent moisture in concrete
decks. In northern climates, this is usually accomplished with: -Correct Answer ✔A
vapor retarder or
A venting sheet
Steel decks should be at least _______ or heavier. -Correct Answer ✔22g
Insulation applied to steel roof decks before the roof membrane is installed should be
applied: -Correct Answer ✔In two separate layers where insulation thickness permits
The top flanges of a steel roof deck should be installed: -Correct Answer
✔Perpendicular to the roof slope
The maximum deflection allowed for a steel deck is: -Correct Answer ✔1/4" per 100 feet
If the steel decks must be spot-welded to structural steel, puddle welds _______ or
larger in diameter are recommended. They should be made on washers and spaced at
least _______ on center. -Correct Answer ✔1/2 inches ... 12 inches
If thermosetting insulation is used over structural decks, the density should be: -Correct
Answer ✔18 to 22 pounds per cubic foot
The correct density for thermosetting insulation is accomplished by: -Correct Answer
✔Compacting
Thermosetting insulation is compacted in two layers if the total thickness is greater than:
-Correct Answer ✔6 inches
Roofing
, Roofing
Thermosetting insulative fills must be protected from latent moisture in roof decks.
Which of the following procedures is recommended? -Correct Answer ✔Install base-ply
vapor barrier and
Install wood nailers at all perimeters and
Install wood nailers at all roof projections
What type of roof is recommended over thermosetting insulative fills -Correct Answer
✔Aggregate
A span rating of _______ means that a plywood panel may be used for roof decking
over supports spaced 32 inches o.c. or for sub flooring over supports spaced 16 inches
o.c. -Correct Answer ✔32/16
On plywood decks not covered with insulation, a base ply should be _______ to serve
as as the base ply of the roof membrane. -Correct Answer ✔Attached with annular-
threaded nails
The choice of membrane type for a roof is frequently determined by: -Correct Answer
✔Geographical location and
Climate
Technical information useful in the selection of roof membranes is provided by the: -
Correct Answer ✔National Bureau of Standards
On low-sloped roofs, felt should be laid _______ the flow of water, beginning at
_______ points in the deck. -Correct Answer ✔Perpendicular ... low
On slopes over 2 inches per foot, felt should be laid: -Correct Answer ✔Parallel to the
slopes
For asphalt roofs, treated wood nailers should be installed perpendicular to the slope
and on 20 - foot centers for slopes up to: -Correct Answer ✔3 inches per foot
A roofing contractor discovers damage done by other trades to a newly installed roof.
What should the roofing contractor do? -Correct Answer ✔Submit a written report to the
general contractor and/or the owner for any visible damage
When layers of felt are joined by hot-mopping, the process is most similar to: -Correct
Answer ✔Welding
Roofing
