Alligatoring: Surface cracking on an asphalt roof that resembles the hide of an alligator.
Asphalt: The primary ingredient in shingles.
Attic: The open space between the decking, beneath the shingles and the upper side of the ceiling.
Base Sheet: A heavy sheet of felt used as the first ply of roofing, underneath modified bitumen roofing.
Bitumen: Applies to both asphalt and coal tar pitch, often modified with rubber or non-metallic additives.
Blisters: Scarring and/or bulging of the roof surface that are often caused by the expansion of air and/or water vapor trapped below the surface, often caused by inadequate ventilation
Buckling: Warping or wrinkling of the roof membrane.
Caulk: Silicone or polymers to fill in a joint.
Closed Valley: A valley where the flashing is covered by the shingles
Course: A row of shingles.
Curb: A wall of wood or masonry built above the level of the roof, surrounding a roof opening.
Deck: The structural roof to which a roof covering is applied.
Drip Edge: A metal flashing to prevent water damage to fascia boards.
Eave: The roof overhang that extends outward, not directly over, the exterior walls.
Exposure: The part of the shingle that is exposed to the weather, and not covered by another shingle.
Fascia: A wood trim board that covers the rafters and decking.
Felt: A roll of roofing materials that are used as underpayments for shingles and other roofing systems.
Gable: The triangular end of an exterior wall, from the eave to the ridge.
Open Valley: A valley is where the flashing is exposed to the weather, often described as looking like a bowling alley gutter.
Parapet: A low wall along the edge of a roof deck.
Ply: A single layer or thickness of roofing material.
Rafters: The lumber supports that make up the skeleton of the roof structure.
Ridge: The line where two slopes join at the highest point of the dormer, hip. or entire roof.
Ridge Caps: Formed shingles to cover the ridges of the roof.
Roll Roofing: A mineral surfaced asphalt roofing, commonly in 3' widths.
Scupper Opening: An opening in the wall of a building to allow drainage of water from the roof surface.
Starter Course: The first row of shingles installed on a roof, at the save. Step Flashing: Metal “L” shaped plates used in a stair step pattern underneath shingles, that ties in with a wall or chimney.
Valley: The line formed by two inclined roof surfaces. The opposite of a roof hip.
Vent: An outlet for release of air from the attic or plumbing.
Ventilators: Devices used on the roof for the ventilation of the interior of the building. Common types are: whirlybird fans, thermostatic fans, and ridge vents.