I1 - Roofing Materials - LT #1 Flashcards
BC Code requires what of all roofs?
The roof should be protected with roofing, including flashing, installed to shed rain effectively & prevent water due to ice damming from entering the roof.
Roofs include what according to the building code?
Decks, balconies, exterior walkways, and similar exterior surfaces serve as roofs where the platforms do not allow free drainage through spaced deck boards.
Roofing has a lifespan as short as:
20 years
Shingle types:
Asphalt, wood, metal, slate & tile
Other roofing types include:
Clay, tile, concrete tile, slate, tar and gravel, selvage, glass reinforced polyester panels, rubberized asphalt and polyvinyl chloride sheet roofing
What is the main factor for choosing roofing materials?
Slope
What materials are suitable for steep and conventional sloped roofs? (4:12)
Asphalt and wood-roofing
What kind of roofing can be used on all roof slopes?
Torch-on roofing
Metal roofing can be used on what slope roof?
3:12 and steeper
Slate, clay tile and concrete tile are generally restricted to roof slopes of
6:12 and steeper
Class A buildings require:
Most fire-resistant, and should be used in areas prone to wildfires. Includes some fiberglass asphalt shingle types, metal, clay, and concrete roofing. Treated wood shakes can be used with a fire barrier material.
Class C building requires:
Least fire-resistant type of roofing and includes some asphalt shingles that have an organic felt base and non-treated wood shakes and shingles. Be able to withstand light fire exposures
Asphalt shingles are most common due to:
Low cost and long life expectancy, can be used for slopes as low as 2:12
What is a three-tab asphalt shingle?
Provides a traditional look, commonly used for ridge cap & starter strips.
Describe a laminated shingle:
Multiple laminations, give a rough appearance, similar to cedar shingle, aka architectural shingle,
both use a base mat material can be organic, fiber glass, asphalt applied to one or both sides to saturate the malt, surface is covered with a mineral or ceramic material to block UV, provide physical protection and give the shingles color
What is the most common wood used for roofing?
Western red cedar
When using a cedar shake, they can be treated with what?
A fire retardant or preservative, but then require a special fastener
What is the difference between shakes and shingles?
Shingles are sawn on both surfaces while shakes are split on one or both surfaces.
Shakes are required to have a butt thickness between:
9mm and 32 mm
Which lasts longer, a cedar shake or a split shake?
Split shake, because the split surface resists the weather better & allows for a small amount of breathing between layers of the shakes.
Wooden shakes can be installed on slopes:
3:12 & steeper. Exposure amount is based on the length of the shingle: 190 mm for shakes450 mm long and 250 mm for shakes 600 mm long
Cedar shingles can be installed on slopes:
3:12 and steeper, exposure length based on roof slope, shingle length & grade.
A top-grade shingle is made from:
100% heartwood, 100% clear, and 100% edge grain.
No 3. shingles are allowed only for:
Using as an under-course for sidewall applications, not for roofing.
What is the minimum allowable slope for built-up and membrane roofing?
1:50
What is built-up roofing?
1) Known as hot tar and gravel roof
2) Built-up roofing consists of three or more layers of roofing felt, mopped with hot tar(bitumen) between layers & covered with a layer of hot tar.
3) Pea gravel is applied over the top for UC protection.
What is membrane roofing?
1) Comes in rolled sheets
2) Common flat & low-slope roofing product
3) Rollled out and overlapping seams fused together using heat or solvents
Main advantage of membrane roofing?
Easily repairable and flexible
What will a three-layer membrane roof have as base layers?
Roofing felt, smooth layer of torch-on roofing and a cap layer of torch on with granulated surface
What other uses does membrane roofing have?
Form weatherproof layer of hidden gutters
Describe roll roofing:
1) Low life span, form wrinkles over time
2) Composition same asphalt shingles
3) Rolls are either single coverage (4” selvage) or double coverage (19”), has asphalt granules on only half of its width.
4) Applied to roof slopes of 3:12 or steeper
19” selvage roofing can be applied to roof surfaces as flat as 2:12
What advantages does metal roofing have?
Non-flammable, lightweight, resists the build-up of moss easily
What is the common finish of a sheet metal roof?
Baked enamel or vinyl plastic. Alum. copper, stainless steel are available but not commonly use.d
What does the profile in a metal sheet do?
It allows the material enough strength to span supports.
Two ways to fasten sheet metal roofing?
Screw with neoprene washer or standing seam sheet
Which type of roofing shingle can last twice as long asphalt shingle?
Metal shingles
What slope is required for more durable, long-lasting roofing materials, such as clay, concrete, or slate?
Extra support and a min. slope of 6:12 for these products
What is a clay tile used for mainly?
Architectural reasons
A disadvantage of clay tile:
Difficult to find leaks
and hard to repair
What are the advantages of concrete tiles?
Long-lasting and fire-proof.
Describe a slate tile”
Slate sheets made into shingles can last 80 to 100 years. Very expensive due to the amount of labor needed.
How is a green roof constructed?
Constructed with a membrane-type roofing covered with a root barrier.
What is solar photovoltaic shingle roofing?
Generate electricity to sell back to the power grid or to use in the home.
What accessories are needed to install roofing?
Underlay, fasteners, eave protection, flashing, and vents.
What type of underlay does a wood shingle require?
Since decay begins on the underside, wood shakes and shingles require a perforated paper underlay, this breathing type of underlay gives the shingle the ability to dissipate moisture.
When a project needs to be weather tight and the roofing can’t be installed immediately, what is needed?
Products such as Rhinoroof paper can be left to exposed weather and UV for up to 60 days.
How is an ice dam formed on an eave?
Snow remains frozen on an exposed eave, but the snow over the living space will melt due to heat loss from the building, creating an ice dam at the eave that can back up water and cause leaks.
When is flashing required?
1) Intersections and some cases for drip edges in order to help protect the lowest edge of the roof.
Which type of flashing material will last the longest?
Lead & copper, used when the flashing must be there indefinitely or design requires use.
Steel flashing is usually coated with:
Enamel coated or galvanized, last as long as other common roofing materials
How is a skylight flashing installed?
1st downside with Base flashing
2nd side opening flashed with Step flashing
3rd: The top of the opening is flashed with a back pan or chimney saddle
How is a chimney flashed?
1st downside with Base flashing
2nd side opening flashed with Step flashing
3rd: The top of the opening is flashed with a back pan or chimney saddle
What is the minimum slope for a flat roof?
1:50
What governs the amount of wood allowed for shingles?
Roof slope, shingle length & shingle grade.
What type of roofing can be used on slopes of 1:50?
Built up, membrane, cold application & felt roofing
What is the purpose of eave protection?
Preventing leaks due to ice damming
What type of roofing material is used for hidden gutters?
Membrane
List two reasons for ventilating attic spaces
To remove excess moisture & prevent overheating
What is the minimum width of valley flashing?
600 mm (Code)
What is the purpose of a Reglet?
Grooves in a concrete wall for counter-flashing
Why are sloped insulation packages used?
Make framing easier by providing the required slope using insulation
Asphalt shingles are prone to wind damage and need:
Adhesive applied at roof edges (Gables and eaves)
Eave protection is not needed when:
1) Over unheated garages, carports & porches
2) Roof overhang measures more than 3’
3) Asphalt shingles on slopes less than 4:12 where shingles are cemented together with a continuous band of cement that is the width of exposure plus 50 mm (2”)
4) On roofs with a slope of 8:12 or steeper
5) In regions with 3500 or fewer degree days
