CE 462 Final Exam Questions With
Accurate Answers
Differences between low-slope roof and a steep roof - ANSWER Low-slope roofs
are nearly flat with a slope less than 17 percent. It is a highly interactive
assembly made up of multiple component
Steep roofs drain quickly giving wind and gravity a opportunity to push or pull
water through the roofing material. Steep roof can be recovered with materials.
Advantages and disadvantages of low-slope roof - ANSWER Advantages:
-are less expensive to construct
-can sometimes serve as a balcony, decks and even landscaped gardens
Disadvantages:
-less forgiving of carelessly performed work
-even small errors in design or construction can cause them to trap puddles of
standing water
-the membranes must be water tight
Advantages and disadvantages of steep roof - ANSWER Advantages:
-the materials are inexpensive and are easy to handle and install
-small damages can be repaired easily
-water vapor vents easily
Disadvantages:
-structures are more complicated geometrically
-require more material than low slope roofs of the same span
Discuss the three positions in which thermal insulation may be installed in a low-
slope roof and the advantages and disadvantages of each - ANSWER 1) Below
structural deck
2) Between the deck and the membrane
3) Above the membrane
1) Advantage: economical and trouble free
Disadvantage: the deck and the membrane is fully exposed to the outside
temperature fluctuations
2) Advantage: protects deck from temp extremes
Disadvantage: the roof membrane remains exposed to extreme temp variations
, 3) Advantage: membrane is protected from extreme temps
Disadvantage: since the membrane is on the warm side of the insulation, it is
immune to vapor blistering problems
Explain function of a vapor retarder in an exterior wall or roof assembly -
ANSWER -Used to slow down the diffusion of water vapor through a building
assembly.
Bituminous roof membrane - ANSWER -Requires more on site labor than single
ply
-A built up roof membrane is created on the roof surface by laminating
overlapping layers of felt together with bitumen
Single ply roof membrane - ANSWER -Single ply are more elastic than bitumen
-brought to the building site in the form of sheets of synthetic rubber, plastic, or
modified bitumen manufactured to the desired overall thickness
Difference between cedar shingles and cedar shakes - ANSWER -Cedar shingles
are sawn from a block
-Cedar shakes are split of using a mallet and froe
-Cedar shingles can be more precisely milled than cedar shakes and can
provide a refined classic appearance
-Cedar shakes are thicker than shingles
What metals are used for architectural sheet metal roofing? What are the
strengths and drawbacks for each? - ANSWER 1) Lead
2) Copper
3) Lead coated copper
4) Stainless steel and titanium
5) Zinc tin alloy coated stainless steel
1) Lead is a toxic material so requires precautions
2) Requires chemical treatments in order to keep original color
3) combine the strength of copper with the grey-white color of lead. Lead and
copper is combined to avoid the staining of wall materials
4) Both stainless steel and titanium are strong and long lasting
5) darker and duller appearance than uncoated stainless steel
What are the benefits of a cool roof - ANSWER -reduce overheating of interior
rooms
-reduces building energy consumption
-increased life span of roof materials
Accurate Answers
Differences between low-slope roof and a steep roof - ANSWER Low-slope roofs
are nearly flat with a slope less than 17 percent. It is a highly interactive
assembly made up of multiple component
Steep roofs drain quickly giving wind and gravity a opportunity to push or pull
water through the roofing material. Steep roof can be recovered with materials.
Advantages and disadvantages of low-slope roof - ANSWER Advantages:
-are less expensive to construct
-can sometimes serve as a balcony, decks and even landscaped gardens
Disadvantages:
-less forgiving of carelessly performed work
-even small errors in design or construction can cause them to trap puddles of
standing water
-the membranes must be water tight
Advantages and disadvantages of steep roof - ANSWER Advantages:
-the materials are inexpensive and are easy to handle and install
-small damages can be repaired easily
-water vapor vents easily
Disadvantages:
-structures are more complicated geometrically
-require more material than low slope roofs of the same span
Discuss the three positions in which thermal insulation may be installed in a low-
slope roof and the advantages and disadvantages of each - ANSWER 1) Below
structural deck
2) Between the deck and the membrane
3) Above the membrane
1) Advantage: economical and trouble free
Disadvantage: the deck and the membrane is fully exposed to the outside
temperature fluctuations
2) Advantage: protects deck from temp extremes
Disadvantage: the roof membrane remains exposed to extreme temp variations
, 3) Advantage: membrane is protected from extreme temps
Disadvantage: since the membrane is on the warm side of the insulation, it is
immune to vapor blistering problems
Explain function of a vapor retarder in an exterior wall or roof assembly -
ANSWER -Used to slow down the diffusion of water vapor through a building
assembly.
Bituminous roof membrane - ANSWER -Requires more on site labor than single
ply
-A built up roof membrane is created on the roof surface by laminating
overlapping layers of felt together with bitumen
Single ply roof membrane - ANSWER -Single ply are more elastic than bitumen
-brought to the building site in the form of sheets of synthetic rubber, plastic, or
modified bitumen manufactured to the desired overall thickness
Difference between cedar shingles and cedar shakes - ANSWER -Cedar shingles
are sawn from a block
-Cedar shakes are split of using a mallet and froe
-Cedar shingles can be more precisely milled than cedar shakes and can
provide a refined classic appearance
-Cedar shakes are thicker than shingles
What metals are used for architectural sheet metal roofing? What are the
strengths and drawbacks for each? - ANSWER 1) Lead
2) Copper
3) Lead coated copper
4) Stainless steel and titanium
5) Zinc tin alloy coated stainless steel
1) Lead is a toxic material so requires precautions
2) Requires chemical treatments in order to keep original color
3) combine the strength of copper with the grey-white color of lead. Lead and
copper is combined to avoid the staining of wall materials
4) Both stainless steel and titanium are strong and long lasting
5) darker and duller appearance than uncoated stainless steel
What are the benefits of a cool roof - ANSWER -reduce overheating of interior
rooms
-reduces building energy consumption
-increased life span of roof materials
