Roofing Terms to Know

• Asphalt: A bituminous waterproofing agent applied to roofing materials during manufacturing. Asphalt plastic roofing cement: An asphalt-based cement used to bond roofing materials, including flashing.
• 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.
• Built-up roof: A flat or low-sloped roof consisting of multiple layers of asphalt and ply sheets.
• Butt edge: The lower edge of the shingle tabs.
• · Caulk: To fill a joint with mastic or asphalt cement to prevent leaks.
• 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.
• 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.
• 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.
• 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 to help prevent damage from water back-up.
• Edging strips: Boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for reroofing with asphalt shingles.
• Feathering strips: Tapered wood filler strips placed along the butts of old wood shingles to create a level surface when reroofing over existing wood shingle roofs.
• Felt: Fibrous material saturated with asphalt and used as an underlayment or sheathing paper.
• Fiberglass mat: An asphalt roofing base material manufactured from glass 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.
• Free-tab shingles: Shingles that do not contain factory-applied strips or spots of self-sealing adhesive.
• Gable: The upper portion of a sidewall that comes to a triangular point 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, with 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. Contains a gable at each end.
• Granules: Ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
• 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 roof: A type of roof containing sloping planes of the same pitch on each of four sides. Contains no gables.
• 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 on 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: Strip shingles containing more than one layer of tabs to create extra thickness. Also called three-dimensional shingles or architectural shingles.
• Lap: To cover the surface of one shingles or roll with another.
• Lap cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.
• Mansard roof: A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.
• · Masonry primer: An asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.
• Mineral-surfaced roofing: Asphalt shingles and roll roofing that are covered with granules.
• Nesting: A method of reroofing with new asphalt shingles over old shingles in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.
• · No-cutout shingles: Shingles consisting of a single, solid tab with no cutouts.
• 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.
• Organic felt: An asphalt roofing base material manufactured from cellulose fibers.
• 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.
• Ply: The number of layers of roofing: i.e. one-ply, two-ply.
• 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 line to the ridge.
• Roll roofing: Asphalt roofing products manufactured in roll form.
• Roofing tape: An asphalt-saturated tape used with asphalt cements for flashing and patching asphalt roofing.
• Run: The horizontal distance from the eaves to a point directly under the ridge. One half the span.
• Saturant: Asphalt used to impregnate an organic felt base material.
• Saturated felt: An asphalt-impregnated felt used as an underlayment between the deck and the roofing material.
• Self-sealing shingles: Shingles containing factory-applied strips or spots of self-sealing adhesive.
• Self-sealing strip or spot: Factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.
• Shading: Slight differences in shingle color that may occur as a result of normal manufacturing operations.
• Sheathing: Exterior grade boards used as a roof deck material.
• Shed roof: A roof containing only one sloping plane. Has no hips, ridges, valleys or gables.
• Slope: The degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.
• Smooth-surfaced roofing: Roll roofing that is covered with ground talc or mica instead of granules (coated).
• 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 of 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.
• Telegraphing: A shingle distortion that may arise when a new roof is applied over an uneven surface.
• Top lap: That portion of the roofing covered by the succeeding course after installation.
• 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.

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