Roof Design and Framing Flashcards
What are the 3 types of roofs?
- Pitched roof
- Shed roof
- Flat roof
What is the rise and run of a conventional slope?
4 in 12 and up
What is the rise and run of a low slope?
2 in 12 to 4 in 12
What is the rise and run of a flat slope?
0 in 12 to 1 in 12
Name the components of the anatomy of a common rafter.
- Ridge Board
- Collar Tie
- Ceiling Joist
- Double Top Plates
- Wall Stud
- Common Rafter
- Plumb Cut
- Tail Cut
- Birdsmouth Cut
True or False. In a slope ( Rise - Run ), the run is always 12.
True.
True or False. Roofs are not measured in degrees.
True.
Name the 7 types of roofs.
- Gable
- Hip
- Shed
- Flat
- Gambrel
- Mansard
- A-Frame
Define “Hip Roof”
It is a roof with 4 sloping sides that meet at a ridge board.
What are the 5 components of framing for a hip roof?
- Common Rafter
- Hip Jack Rafter
- Hip Rafter
- Ridge Board
- Wall Plate
True or False. Overhangs are a method of water management.
True. Overhangs help keep water away from the walls.
What are the 4 components of framing for a flat roof?
- Common joists
- Double trimmer
- Lookout
- Header
What is particularly cost-efficient about gambrel roofs?
A gambrel can create a 2nd story within the roof. Roofing materials are cheaper than envelope materials.
What are overhangs used for?
- Block the summer sun
- Lets in the winter sun
- Keeps water away from walls
However, they are not used in dry climates.
What is a “Gable End”?
also known as Eave; the extension of a gable roof beyond the end wall.
What is a bird’s mouth?
It is a right-angled notch cut on the underside of a rafter to fit over a wall.
What is the principal difference between a roof rafter and a roof joist?
Roof rafter supports loads of a pitched roof, whereas roof joists support loads of a flat roof.
In what situation does a ceiling joist need to be calculated like a floor joist?
A ceiling joist needs to be calculated like a floor joist when the roof is an attic, where live and dead load from the occupants and the roof need to be supported.
True or False. A bird’s mouth cut in a rafter is made near the eave.
True.
In the building industry, the slope of a roof is generally expressed in…
a. degrees
b. rise to run ratio
c. radians
d. both a and b
b. rise to run ratio
The cornice forms the connection between the __________ and the ________ of the house.
- Roof
- Sidewalls
What are the 3 requirements to ceiling joists design in a roof?
- Load to be supported ( How much snow is projected to fall )
- Span of ceiling joists
- Spacing of joists
Name some of the supports a ceiling joist might use/need.
- Attic Knee Walls
- Collar Ties ( for slope 4 in 12, located at 1/3 )
True or False. A ceiling joist can act as a tie for an exterior wall.
True.
There are 2 types of dormer windows. Name them.
- Gable
- Shed
What is the space that is planned between the framing and the brick/stone of the chimney?
2”
In a __________ roof, if the rake end width exceeds _____ inches, we must use cantilever proportions for the lookouts.
- Gable
- 12
True or False. Hip roofs have rake ends.
False.
Define “Cornice”
The connection between the roof and the sidewalls of the building. ( Connection between roof and wall )
Define “Eave”
also known as Cornice; it is the horizontal edge at the low end of a sloping roof.
Name the 3 types of roof openings.
- Dormer
- Skylight
- Chimney
What is the difference between a Gable Dormer and a Shed Dormer?
Gable Dormer:
- Vertical Glass
- Own Roof
- Own Walls
- Sits on a trimmer
Shed Dormer:
- Shed Dormer Rafter
- Double Rafters
- Exterior Wall Below
( + Weight transfers, lined up with wall to transfer loads )
Name the 2 types of skylights.
- Curb Mount
- Framed-in-place
For a skylight, how is the glazing installed?
Parallel to the roof slope.
( + 8 inch curve on a flat roof )
In the case of chimneys, what methods are used to prevent the passage of water?
- Cap flashing
- Step flashing
To prevent build-up ( snow, leaves, branches, etc. ) what is installed centered on the backside of the chimney?
Saddle.
How much space should be leave around the chimney?
2”
Define “Underlayment”
It is a weather-resistant material for covering and protecting a roof deck before shingles are applied.
What is underlayment?
Roofing underlayment is what lies between the shingles and the roof sheathing, or roof deck, which is typically either plywood or OSB. It is installed directly on the roof deck and provides a secondary layer of protection from the elements, including rain, snow, and wind.
What is the purpose of underlayment?
It is to provide a second layer of protection located between the roof shingles and the roof deck. It is a waterproofing product.
What are the 4 characteristics underlayment must have?
- Industry-Leading Walkability
- Grip
- Trusted Dupont Tyvek Quality
- Easy to Chalk
What is “Ice Damming”?
An ice dam is an ice build-up on the eaves of sloped roofs.
What causes ice damming?
Ice damming occurs when heat from the house heats the snow on a sloped roof and then melts the snow on the roof for it to reach the eave to freeze there.
How to prevent ice damming?
Better insulation.
What method is used to protect roof valleys from snow/water accumulation?
An ice + water shield and metal valley flashing are installed.
Name the different types of roofing materials.
- Asphalt Shingles
- Metal Roofing
- Clay Tile
- Cedar Shakes/Shingles
For flat roofs:
- Built-up roofing
- Membrane roofing
What are the 4 requirements when choosing roofing materials?
- Longevity
- Water proofing
- Fire resistance
- Contributing to overall aesthetic design
At how many inches should the end roll of an underlayment overlap?
4”
True or False. Poor attic ventilation can ruin your insulation, destroy your shingles, and potentially raise your energy bills.
True.
What are the ventilation requirements?
- Keep attic cool
- Air must come in through the soffit vent
- Air must come out through the ridge vent
Ventilation:
Low Slope 0-2:12
Conventional Slope 4:12 +
Low Slope: 1/150th
Conventional Slope: 1/300th
What are the causes of shingle deterioration?
- UV rays
- Heat ( Thermal shock )
- Intense winds
- Rain, snow, hail, ice, etc.
- Trees
Name the 3 types of roof valleys.
- Open valley
- Closed valley
- Woven valley
What is a roof valley?
It is when two roof slopes come together.
True or False. Wood shingles and shakes cannot be installed on a roof less than a 4-in-12 slope.
True.
Name the 5 types of materials for metal roofing.
- Copper
- Aluminum
- Stainless steel
- Galvanized steel
- Painted steel
True or False. Metal roofing cannot be installed on flat roofs.
True.
What are the 3 methods associated with membrane roofing?
- Fully adhered
- Mechanically fastened
- Loosely ballasted
What are the 5 types of membrane roofing?
- PVC
- Modified Bitumen
- EPDM
- Rubber
- TPO
Name the disadvantages of using roof trusses.
- Roof trusses leave no room for an attic space, due to their web
- Roof trusses have a tendency to buckle/warp, which could affect the structural integrity of a building.
Name the advantages of using roof trusses.
- Roof trusses are pre-fabricated, which allows for a more cost-efficient installation. They don’t require any preparation in order to be used effectively.
Name the 5 different types of trusses.
- King Post Truss
- Howe Truss
- Fink or W Truss
- Scissor Truss
- Mono Pitch Truss
Other than specifying the pitch, span, and overhang detail, what else must a designer specify to the truss manufacturer?
Raised heel
Why are the roof valleys seen as a critical area in roof construction?
The intersecting roof panes create a non-continuous area on the roof, which leaves that area prone to snow and water accumulation.
The material placed directly under the roof shingle is known as…
a. Sheathing
b. Underlayment
c. Air Barrier
d. Insulation
b. Underlayment
What is the purpose of using a self-adhered membrane at the eave of a pitched roof?
To serve as a snow/water shield in preventing ice damming.
Name 1 of the causes of ice buildup at the eave end of a roof.
Poor Insulation.
What is the purpose of a baffle or channel?
To serve as a passage of ventilation in a roof space.
What are the factors used for a low/conventional slope of an insulated ceiling area?
Low Slope: 1/150th
Conventional Slope: 1/300th
Name examples of vents:
- Turbine
- Maximum vent
- Flat roof vent
