The definitions are arranged in alphabetical order:

A | B | C | D | E | F | G | H | I | L | M | N | O | P | Q | R | S | T | U | V | W

Algae discoloration:: A type of roof discoloration caused by algae. Commonly called fungus growth.
American method:: Application of giant individual shingles with the long dimension parallel to the rake. Shingles are applied with a 3/4-inch space between adjacent shingles in a course.
ASTM:: American Society for Testing and Materials. A voluntary organization concerned with development of consensus standards, testing procedures and specifications.
Asphalt:: A bituminous waterproofing agent applied to roofing materials during manufacturing.
Asphalt plastic roofing cement:: An asphalt-based cement used to bond roofing materials. Also known as flashing cement or mastic; should conform to ASTM D-4586.

Back Surfacing:: Fine mineral matter applied to the back side of shingles to keep them from sticking.
Base flashing:: That portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof covering.
Blisters:: Bubbles that may appear on the surface of asphalt roofing after installation.
Brands:: Airborne burning embers released from a fire.
Bridging:: A method of reroofing with metric-sized shingles.
Built-up roof:: A flat or low-sloped roof consisting of multiple layers of asphalt and ply sheets.
Bundle:: A package of shingles. There are 3, 4 or 5 bundles per square.
Butt edge:: The lower edge of the shingle tabs.

Caulk:: To fill a joint with mastic or asphalt cement to prevent leaks.
Cement:: See asphalt plastic roofing cement.
Chalk line:: A line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment purposes.
Class "A":: The highest fire-resistance rating for roofing as per ASTM E-108. Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building.
Class "B":: Fire-resistance rating that indicates roofing materials are able to withstand moderate exposure to fire originating from sources outside the building.
Class "C":: Fire-resistance rating that indicates roofing materials are able to withstand light exposure to fire originating from sources outside the building.
Closed cut valley:: A method of valley treatment in which shingles from one side of the valley extend across the valley while shingles from the other side are trimmed two inches from the valley centerline. The valley flashing is not exposed.
Coating:: A layer of viscous asphalt applied to the base material into which granules or other surfacing is embedded.
Collar:: Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called a vent sleeve.
Concealed nail method:: Application of roll roofing in which all nails are driven into the underlying course of roofing and covered by a cemented, overlapping course. Nails are not exposed to the weather.
Condensation:: The change of water from vapor to liquid when warm, moisture-laden air comes in contact with a cold surface.
Counter flashing:: That portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.
Course:: A row of shingles or roll roofing running the length of the roof.
Coverage:: Amount of weather protection provided by the roofing material. Depends on number of layers of material between the exposed surface of the roofing and the deck; i.e., single coverage, double coverage, etc.
Cricket:: A peaked saddle construction at the back of a chimney to prevent accumulation of snow and ice and to deflect water around the chimney.
Cutout:: The open portions of a strip shingle between the tabs.

Deck:: The surface installed over the supporting framing members to which the roofing is applied.
Dormer:: A framed window unit projecting through the sloping plane of a roof.
Double coverage:: Application of asphalt roofing such that the lapped portion is at least two inches wider than the exposed portion, resulting in two layers of roofing material over the deck.
Downspout:: A pipe for draining water from roof gutters. Also called a leader.
Drip edge:: A non-corrosive, non-staining material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.
Dutch lap method:: Application of giant individual shingles with the long dimension parallel to the eaves. Shingles are applied to overlap adjacent shingles in each course as well as the course below.