Steep slope roofing includes watershedding types of roof coverings installed on slopes exceeding 3:12 (14 degrees).There are six generic classifications of steep slope roof coverings.
- Asphalt shingles
- Clay tile and concrete tile
- Metal roof systems for steep-slope applications
- Wood shakes and wood shingles
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 watershedding material.