Some Terms You Should Know
Butt— The larger, exposed end of a shingle.
Deck–Plywood or oriented-strand board (OSB) sheathing used as a base for securing roofing materials.
Drip edge— An L-shaped metal strip positioned along a roof’s edges to allow water to run off roof without running down eaves or siding.
Eaves— On a sloped roof, the horizontal underside that projects out from house wall.
Exposure— The part of a shingle that is exposed to the weather, usually less than half its actual length.
Felt or underlayment— Asphalt-impregnated roofing paper that creates a secondary, watertight barrier between many roofing products and the roof deck.
Flashing— Metal pieces that keep water from seeping into intersections such as valleys or joints at vertical walls, or around roof penetrations such as chimneys or vent pipes.
Pitch— Roof slope expressed as the ratio of a roof’s rise (vertical distance) to each foot of run (horizontal distance). A “4-in-12 pitch” means the roof rises 4 inches for every 12 inches of horizontal distance.
Rafters— The framework that supports the roof deck and roofing. On a sloped roof, these are the angled timbers on the underside.
Rake–The sloped edge of a roof over a wall.
Ridge–The peak where two sloped roof sections meet.
Square— A measurement of roof area that equals 100 square feet (an area 10′ by 10′).
Valley— The angle formed where two sloping roof surfaces intersect