Key Roofing Terms
Natural gas vent: Vent used to exhaust any natural gas unit.
Nesting: A method of re-roofing 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.
New construction: Installing a roof system on new construction.
No-cutout shingles: Shingles consisting of a single, solid tab with no cutouts.
Non-prorated warranty: A warranty which provides full replacement costs for the item(s) covered during the full term of the warranty. In contrast, a prorated warranty merely reimburses a percentage of original costs, depending on the depending on how many years the roof’s been in service.
Non-veneer panel: Any wood based panel that does not contain veneer and carries an APA span rating, such as wafer board or oriented strand board.
Normal slope application: Method of installing asphalt shingles on roof slopes between 4 inches and 21 inches per foot.
Open soffit: Underside of an overhang that is not finished.
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 and asphalt bitumen.
Organic shingle: An asphalt shingle reinforced with organic material manufactured from cellulose fibers and asphalt bitumen.
OSB sheeting: Oriented strand board. Directionally formed particleboard comprising cross-bonded plies. Substitute for plywood in building.
Overhang: That portion of the roof structure that extends beyond the exterior walls of a building.
Pallets: Wooden platforms used for storing and shipping bundles of shingles or roll goods.
Pan metal: Thin metal used above chimneys or skylights.
Parapet: A low protective wall that extends above the roofline or balcony for support.
Pipe Flashings: A boot that seals a plumbing vent that penetrates the roof deck.
Pitch: Also known as “slope”, pitch is the measure of how “steep” a roof is. For example, if a roof is “4 in 12”, the roof rises 4 inches for every horizontal run of 12 inches. The pitch of the roof is a big factor in determining the kinds of materials that can be used and the longevity of the roof. Usually, a steeper roof (higher pitch) will last longer due to its better drainage capabilities.
Plastic cement: A compound used to seal flashings and in some cases to seal down shingles as well as for other small waterproofing jobs. Where plastic cement is required for sealing down shingles, use a dab about the size of a half dollar unless otherwise specified.
Ply: The number of layers of felt used in hot roofing. (i.e. 1,2,3-ply)
Plywood: A structural material made of layers of wood glued together, usually with the grains of adjoining layers at right angles.
Pocket: A horizontal flat area created on a pitched roof.
Racking: Roofing application method in which shingle courses are applied vertically up the roof rather than across and up. Not a recommended procedure.
Rafter: The supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate usually 16 or 24 inch on center.
Rafter tail: The lower end of a roof truss that extends beyond outer wall.
Rake: The inclined edge of a sloped roof over a wall from the eave to the ridge
Random-tab shingles: Shingles on which tabs vary in size and exposure.
Release tape: A plastic or paper strip that is applied to the back of self-sealing shingles. This strip prevents the shingles from sticking together in the bundles, and need not be removed for application.
Re-cover (overlay): The installation of a new roof system over an existing system without removing an existing system.
Re-roofing: Installing a new roof system on a building that is not new.
Ridge: The uppermost, horizontal external angle formed by the intersection of two sloping roof planes.
Ridge Venting: A vent system used along the horizontal top of a roof for much better air space ventilation which is rated approximately 14 sq. inches per foot.
Rigid insulation: Dense insulation boards nailed over a roof deck that is the finished ceiling.
Rise: The vertical distance from the eaves line to the ridge.
Roll roofing: Asphalt roofing products manufactured in roll form which are not approved for residential use.
Roof scaffolding: Brackets used on steeper roofs that hold 2×6 boards to prevent sliding.
Roof to wall flashing: Flashing used at top of roof section that is over the roofing and under the siding.
Roof top loading: The delivery of roofing material to job site set on top of the roof structure.
Roof truss: A framework of beams forming a rigid structure.
Roofing tape: An asphalt-saturated tape used with asphalt cements for stabilizing flashing and patching asphalt roofing.
Run: The vertical distance from the eaves to a point directly under the ridge. One half the span.
Saturant: Asphalt used to impregnate an organic or inorganic felt base material.
Scuppers: Drain that allows water on roof deck or gutter to flow into a downspout.
Self-sealing shingles: Shingles containing factory-applied strips or spots a thermal sealing tab cement to firmly cement the shingles together automatically after they have been applied properly and exposed to warm sun temperatures. In warm seasons, the seal will be complete in a matter of days. In colder seasons, sealing time depends on the temperature and amount of direct sunlight hitting the shingles. Hand sealing with plastic cement can be done to ensure sealing in winter.
Self-sealing strip or spot: Factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application. Also known as self-sealing cement.
Selvage: That portion of roll roofing overlapped by the succeeding course to obtain double coverage.
Shading: Slight differences in shingle color that may occur as a result of normal manufacturing operations.
Shake tear off: Removal of shake roof from an existing roof structure.
Sheeting: Exterior grade boards used as a roof deck material. “Skip sheeting” is used alone or in combinations with solid sheeting for installation of shakes. Skip sheeting allows air circulations under the shakes by using 1×4 or 1×6 boards that are evenly spaced so that air can move under the shakes.
Shed roof: A roof containing only one sloping plane. Has no hips, ridges or valleys.
Sheeting 1×8: boards used to make solid roof deck, usually used prior to the use of plywood (prior to 1960).
Shiplap: A 1×8 lap edge board used to solid sheet roofs before the introduction of plywood in approximately 1960.
Single coverage: Asphalt roofing that provides one layer of roofing material over the deck.
Skip-sheeting: A method of the installation of roof sheeting usually used under shake roofs, which originally allowed the shakes to dry from both sides.
Skylight: A unit which covers an opening in a roof deck allowing light to penetrate the building.
Skylight flashing: Metal flashing that is installed around a skylight curb that integrates with the roofing to make the roof water-tight.
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). It’s recommended to coat these roofs with aluminum roof coating.
Soffit: The finished underside of the eaves.
Soffit venting: The installation of a vent material along the lower underside portion of the overhang as a ventilation system. This venting should be used in conjunction with other venting material (e.g., ridge vent) as it not intended for use by itself.
Span: The horizontal distance from truss to truss.
Specialty eaves flashing membrane: A self-adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind-driven rain.
Square: A unit of roof measure covering 100 square feet.
Square-tab shingles: Shingles on which tabs are all the same size and exposure.
Starter strip: Asphalt roofing applied at the eaves that provides protection by filling in the spaces under the cutouts and joints of the first course of shingles.
Steep slope application: Method of installing asphalt shingles on roof slopes greater than 21 inches per foot.
Step flashing: Flashing application method used where a vertical surface meets a sloping roof plane.
Storm Collar: Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. The collar is also called a vent sleeve.
Strip shingles: Asphalt shingles that are approximately three times as long as they are wide.
Strong-Hold Nails: 1 inch round or square-head nail used to fasten base sheet on hot or torch down roofs.
Three-tab shingles: A composition shingle that is 39 inches long, and has the appearance of three separate shingles 13 inches wide.
Torch down: A newer roofing material which is single ply modified bitumen.
Torch down pocket: Single ply modified bitumen applied in the pocket of flat or low pitch areas of composite, shake tile, or metal roofs.
Turbines: A mechanical vent that spins and vents approximately 300 sq. ft. of attic space.
Valley: The “V” created where two sloping roof planes meet each other.
Vent: A flashing or screen used to allow heat and moisture to escape.
Vented ridge: Vent used along a ridgeline which allows heat and moisture to escape.
Wood rot: Deterioration of wood used in an existing structure.
Wood work: The removal and replacement of deteriorated wood beneath the roof on an existing structure.
Zinc Strips: 3 inch solid zinc metal used to prevent moss and algae growth.