Click on colorful terms to see a picture. Some terms, such as various methods, will not have pictures.
Camber: A slight convex curve of a surface, such as in a prestressed concrete deck.
Caulk: To fill a joint with mastic or asphalt cement to help prevent leaks.
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 E108. 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.
Cornice: The decorative horizontal molding or projected roof overhang.
Counter Flashing: That portion of the flashing attached to a vertical surface to help 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 (single coverage, double coverage, etc.).
Cricket: A peaked water diverter installed behind chimneys and other large roof projections. Effectively diverts water around projections.
Cupola: A relatively small roofed structure, generally set on the ridge or peak of a main roof area.
Cupping: When shingles are improperly installed over an existing roof or are over-exposed, they may form a curl or cup. May also be due to a manufacturing defect.
Cutout: The open portions of a strip shingle between the tabs.
Damper: An adjustable plate for controlling draft.
Deck or Decking: The substrate over which roofing is applied. Usually plywood, wood boards, or planks.
Delamination: Separation of the laminated layers of a component or sysem.
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 material over the deck.
Downspout: A pipe for draining water from roof gutters. Also called a leader.
Drip Edge: A noncorrosive, nonstaining material used along the eaves and rakes to allow water runoff to drip clear of underlying construction.
Dutch Lap Method: Application of very large 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.