Some key roofing terms are listed below:
Asphalt: A waterproofing agent applied to roofing materials during manufacturing.
Asphalt plastic roofing cement: An asphalt-based sealant used to bond roofing materials. Also known as flashing cement, roof tar, bull or mastic.
Back surfacing: Granular material applied to the back side of shingles to keep them from sticking during delivery and storage.
Base flashing: That portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof.
Built-up roof: Multiple layers of asphalt and ply sheets bonded together.
Butt edge: The bottom edge of the shingle tabs.
Caulk: To fill a joint to prevent leaks.
Closed valley: The valley flashing is covered by shingles.
Coating: A layer of viscous asphalt applied to the outer roof surface to protect the roof membrane.
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 covered by a cemented, overlapping course.
Counter flashing: That portion of the flashing attached to a vertical surface above the plane of the roof to prevent water from migrating behind the base flashing.
Course: Row of shingles that can run horizontally, diagonally or vertically.
Cricket: A peaked water diverter installed at the back of a chimney to prevent accumulation of snow and ice and to deflect water.
Deck: The top surface of which a roof system is applied, surface installed over the supporting framing members.
Double coverage: Asphalt roofing whose lapped portion is at least two inches wider than the exposed portion, resulting in two layers of roofing material over the deck.
Downspout: A pipe for draining water from roof gutters to drain. Also called a leader.
Drip edge: L-shaped flashing used along the eaves and rakes to allow water run-off into the gutters and to drip clear of underlying construction.
Eave: The part of the roof that overhangs or extends outward and is not directly over the exterior walls or the buildings interior.
Exposed nail method: Application of roll roofing where nails are driven into the overlapping course of roofing. Nails are exposed to the elements.
Fascia: A wood trim board used to hide the cut ends of the roof’s rafters and sheathing.
Felt: Fibrous material used as an underlayment or sheathing paper, describes roll roofing materials.
Flashing: Pieces of metal or roll roofing used to form water seal around vent pipes, chimneys, adjoining walls, dormers and valleys.
Gable: The end of an exterior wall that comes to a triangular point at the ridge of a sloping roof.
Granules: Ceramic-coated and fired crushed rock that is applied as the top surface of asphalt roofing products.
Gutter: The trough that channels water from the eaves to the downspouts. Usually attached to the fascia.
Head lap: An overlapping of shingles or roofing felt at their upper edge.
Hip: The fold or vertical ridge formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.
Ice dam: Condition forming water back-up at the eave areas by the thawing and re-freezing of melted snow on the overhang. Can force water under shingles, causing leaks.
Interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.
Laminated shingles: Strip shingles made of two separate pieces laminated together to create extra thickness. Also called three-dimensional and architectural shingles.
Lap: Surface where one shingle or roll overlaps with another during the application process.
Mansard roof: A design with a nearly vertical roof plane connected to a roof plane of less slope at its peak. Contains no gables.
Mineral stabilizers: Finely ground limestone, slate, traprock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.
Nesting: A method of reroofing, installing a second layer of new asphalt shingles, in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.
Pitch: The degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.
Low Slope – Roof pitches that are less than 30 degrees.
Normal Slope – Roof pitches that are between 30 and 45 degrees.
Steep Slope – Roof pitches that are more than 45 degrees.
Rafter: The supporting framing that makes up the roof structure; immediately beneath the deck; the roof sheathing is nailed to the rafters.
Rake: The inclined edge of a sloped roof over a wall from the eave to the ridge. They can be close or extended.
Ridge: The horizontal external angle formed by the intersection of two sloping sides of a roof at the highest point of the roof, hip or dormer.
Run: The horizontal distance between the eaves and a point directly under the ridge; or one half the span.
Selvage: That portion of roll roofing overlapped by the application of the roof covering to obtain double coverage.
Sheathing: Exterior grade boards used as a roof deck material.
Shed roof: A single roof plane with no hips, ridges, valleys or gables, not connected to any other roofs.
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 that extends from the fascia to the siding and hides the bottom of an overhang.
Soil stack: A vent pipe that penetrates the roof.
Span: The horizontal distance from eaves to eaves.
Specialty eaves flashing membrane: A self-adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind driven rain.
Starter strip: Asphalt roofing applied at the eaves as the first course of shingles installed.
Tab: The weather exposed surface of strip shingles between the cutouts.
Telegraphing: Shingles installed over an uneven surface that show distortion.
Truss – A combination of beams, bars and ties, usually in triangular units to form a framework for support in wide span roof construction.
UL label: Label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing.
Underlayment: A layer of asphalt based rolled materials installed under main roofing material before shingles are installed to provide additional protection for the deck.
Valley: The internal angle formed by the intersection of two inclined roof surfaces to provide water runoff.
Vapor barrier/retarder: Any material that prevents the passage of water or water vapor through it.
Vent: Any device installed on the roof as an outlet for air to ventilate the underside of the roof deck.