Roofing Terminology

HomeRoofing 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 and 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.

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