Steep Slope Roofing
Roof pitch is one of the most used terms in the roofing industry. (Also referred to as roof slope or roof slant.) The angle or pitch of a roof, is determined by the number of inches it rises vertically for every 12 inches it extends horizontally. Generally all slopes higher than 4:12 are considered steep slopes.
So what does the 7/12 in the example to the right mean? The 7 means that the roof rises 7" for every 12" it runs.
Roofing types and roofing product are typically divided up into two primary categories: steep slope and low slope. Most single family homes are constructed with a pitch or slope to the roof, therefore steep slope roofing is referred to “residential” roofing. The term low slope roofing is synonymous with “commercial roofing” due to most commercial buildings have "flat”roof designs.
Steep-slope roof systems typically are composed of individual pieces or components installed in shingle fashion. Steep-slope roof assemblies typically consist of three primary parts:
- Roof deck — a roof deck is the structural substrate and usually is a wood-based material such as plywood or oriented strand board (OSB).
- Underlayment — underlayment provides temporary protection until a roof covering is installed and provides a secondary weatherproofing barrier. Sometimes underlayment is referred to as "felt" or "paper."
- Roof covering — the roof covering is the external water shedding material.