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
