Roofing Flashcards
What defines a low-slope roof?
Slope of 2:12 ratio or less
Can/should a roof be completely flat?
No, some slope is needed to drain water efficiently
What is the minimum slope for roofs generally?
1/4” per 1’
What is a roof deck?
Structural surface that supports the roofing system
What are the three ways to install insulation on a roof?
Below the deck
B/w deck and roof membrane
above roof membrane
What is the cheapest and easiest way to install insulation on a roof?
Insulation below the deck
What is the best way to install insulation on a roof?
Above roof membrane
Three types of membranes:
Bituminous
Single-ply
Fluid-applied
What are some defining characteristics of bituminous roof membranes?
Most made from asphalt
Typically multiple layers of materials
Two types: Built-up Roof, Modified bitumen
What are some defining characteristics of Built-up roof membranes (BURs)?
Oldest low-slope roof membrane system
Overlapping layers of asphalt-saturated felts are bedded in hot asphalt
What are some defining characteristics of Modified Bitumen Roofs (Mod-Bit)?
Greater elasticity
Greater durability
Consistent material quality
Bonded by torching
What are some defining characteristics of Single-ply roof membranes?
Single layer
Factory made
Plastic and rubber compounds
Upon heating, what type of roof membrane can be re-softened?
Thermoplastic
Why can’t thermoset roof membranes be softened when heated?
Cross-linking of the molecular chains makes it more chemically stable
What are the benefits of using Thermoset single-ply roof membrane?
Better outside of joints
UV resistance
Chemical resistance
Cost
What are the benefits of using Thermoplastic single-ply roof membrane?
Better at joints
Better flexibility
Chemical resistance
Easier to repair
What are some applications of fluid-applied membranes?
Around penetrations, over doubly-curved surfaces, unusual geometric conditions
Prefabricated metal roofing panels can be used at slopes as low as:
1/4” per foot
What is the slope requirement for a steep roof?
Greater than 2:12
2 roofing systems used for steep roofs?
Metal
Tile
What are shingles?
Small roofing units w/ staggered vertical joints
What are the common used woods for wood shingles and why?
Cedar, redwood
Naturally decay-resistant
What makes a wood shake different than wood shingle?
Thicker
Briefly define asphalt or composition shingles.
Cut from heavy, asphalt-impregnated fiberglass
Surface mineral granules give color, protect from UV degradation
What is the life expectancy of Asphalt shingles?
15-25 yrs
What is the life expectancy of mineral surfaced roll roofing?
6-15 yrs
What is the minimum slope for slate shingles?
4:12
What is the durability of slate shingles?
60-80 yrs
What is the minimum slope for clay and concrete tiles?
4:12
What is the life expectancy of clay and concrete tiles?
30-75 yrs
Which steep roof material lasts the longest?
Slate
Definition of cool roof?
Roofs meeting minimum reflectance requirements of green rating systems
What are some benefits of green roofs?
Reduce noise transmission
Reduce stormwater runoff
Reduce urban heat island effects
List some components of green roofs.
Plant materials
Soil
filter fabric
drainage layers
Roof deck
