We understand that roofing terms can be confusing to those who are not in the industry. This information sheet provides roofing terms to help you make an educated decision about your roofing needs.
Collar: Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called a vent sleeve.
Counter flashing: The portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.
Course: A row of shingles running the length of the roof.
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.
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.
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.
Eaves: The horizontal, lower edge of a sloped roof.
Eave flashing: Additional layer of roofing material applied at the eaves a rakes to allow water run-off to drip clear of underlying construction.
Felt: Fibrous material saturated with asphalt and used as an underlayment or sheathing paper. Organic felt is an asphalt roofing base material manufactured from cellulose fibers.
Flashing: Pieces of galvanized metal (usually aluminum or copper) or roll roofing used to prevent seepage of water into a building around any intersection or projection in a roof such as vent pipes, chimneys, adjoining walls, dormers, and valleys.
Gable: The upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
Gutter: The trough that channels water from the eaves to the downspouts.
Hip: The inclined external angle formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.
Hip shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
Ice dam: Condition formed at the lower roof edge by the thawing and re-freezing of melted snow of the overhang. Can force water up and under shingles, causing leaks.
Interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.
Laminated shingles: Asphalt strip shingles containing more than one layer of tabs to create extra thickness. They are also called three-dimensional shingles or architectural shingles.
Open valley: Method of valley construction in which shingles on both sides of the valley are trimmed along a chalk line snapped on each side of the valley. Shingles do not extend across the valley. Valley flashing is exposed.
Overhang: That portion of the roof structure that extends beyond the exterior walls of a building.
Pitch: The degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.
Rafter: The supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.
Rake: The inclined edge of a sloped roof over a wall.
Ridge: The uppermost, horizontal external angle formed by the intersection of two sloping roof planes.
Ridge shingles or ridge cap: Shingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.
Rise: The vertical distance from the eaves lines to the ridge.
Roll roofing: Asphalt roofing products manufactured in roll form.
Roofing tape: An asphalt-saturated tape used with asphalt cement for flashing and patching asphalt roofing.
Run: The horizontal distance from the eaves to a point directly under the ridge. One half the span.
Slope: The degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.
Soffit: The finished underside of the eaves.
Soil stack: A vent pipe that penetrates the roof.
Span: The horizontal distance from eaves to eaves.
Square: A unit of roof measure covering 100 square feet. A roof with a field area of 2,500 square feet would be called a 25 square roof.
Starter strip: Asphalt roofing applied at the eaves that provide protection by filling in the spaces under the cutouts and joints o the first course of shingles.
Step flashing: Flashing application method used where a vertical surface meets a sloping roof plane.
Tab: The exposed portion of strip shingles defined by cutouts.
Underlayment: Asphalt saturated felt used beneath roofing to provide additional protection for the deck.
Valley: The internal angle formed by the intersection of two sloping roof planes.
Vapor retarder: Any material used to prevent the passage of water vapor.
Vent: Any outlet for air that protrudes through the roof deck such as a pipe or stack. Any device installed on the roof gable, or soffit for the purpose of ventilating the underside of the roof deck.