Roofing Terminology
Architectural Shingles: See laminated shingles.
Built-up Roofing: A roof consisting of multiple layers of asphalt and ply sheets.
Cricket: A peak saddle construction at the back of the chimney to prevent accumulation of snow or ice and used to deflect water around the chimney.
Collar: Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening; also called a vent sleeve.
Deck/sheathing: The surface, usually plywood or oriented strand board (OSB), to which roofing materials are applied.
Dormer: A small structure projecting from a sloped roof, usually with a window.
Drip edge: An L-shaped strip (usually metal) installed along roof edges to allow water run off to drip clear of the deck, eaves and siding.
Eave: The horizontal lower edge of a sloped roof.
Fascia: A Flat board that is nailed to the ends of a roof rafter; sometimes supports a gutter. In low-slope roofing, the vertical or steeply sloped roof or trim located at the perimeter of a building.
Felt/underlayment: A sheet of asphalt-saturated material (often called tar paper) used as a secondary layer of protection for the roof deck.
Fire rating: System for classifying the fire resistances of various materials. Roofing materials are rated Class A, B or C, with Class A materials having the highest resistance to fire originating outside the structure.
Flashing: Pieces of metal used to prevent the seepage of water around any intersection or projection in a roof system, such as vent pipes, chimneys, valleys and joints at vertical walls.
Gable: The upper portion of a sidewall that comes to a triangle at the ridge of a sloping roof.
Gable Roof: A type of roof containing sloping planes of the same pitch on each side of the ridge. This roof contains a gable at each end.
Gambrel Roof: A type of roof containing two sloping planes of different pitch on each side of the ridge. The lower plane has a steeper slope than the upper. This roof contains a gable at each end.
Granules: Ceramic coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
Hip Roof: A type of roof containing sloping planes of the same pitch on each of four sides. This roof contains no gables.
Laminated Shingles: Strip shingles containing more than one layer of tabs to create extra thickness; also called three-dimensional shingles or architectural shingles.
Oriented strand board (OSB): Roof deck panels (4 by 8 feet) made of narrow bits of wood, installed lengthwise and crosswise in layers, and held together with resin glue. OSB often is used as a substitute for plywood sheets.
Penetrations: Vents, pipes, stacks, chimneys-anything that penetrates a roof deck.
Pitch: The degree of roof inclined expressed as the ratio of the rise, in feet, to the span, in feet.
Rafters: The supporting framing to which a roof deck is attached.
Rake: The inclined edge of a roof over a wall.
Ridge: The top edge of two intersecting sloping roof surfaces.
Self-sealing Strip - Factory applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.
Sheathing: The boards or sheet materials that are fastened to rafters to cover a house or building.
Slope: Measured by rise in inches for each 12 inches of horizontal run: A roof with a 4-in-12 slope rises 4 inches for every foot of horizontal distance.
Soffit: Area or roof under overhang.
Square: The common measurement for roof area. One square is 100 square feet (10 by 10 feet).
Truss: Engineered components that supplement rafters in many newer homes and buildings. Trusses are designed for specific applications and cannot be cut or altered.
Underlayment - Asphalt saturated felt used beneath roofing to provide additional protection for the deck.
Valley: The angle formed at the intersection of two sloping roof surfaces.
Vapor retarder: A material designed to restrict the passage of water vapor through a roof system or wall.
