Roofing Terms Defined
Roofing Terms Defined N - Z
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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 replacement costs, depending on the age of the roof.
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 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.
Organic shingle: An asphalt shingle reinforced with organic material manufactured from cellulose fibers.
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.
Parapet: A low protective wall that extends above the roofline or balcony for support.
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 roofing: i.e. one-ply, two-ply.
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.
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 shingles: 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.
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 should 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.
Sheathing: Exterior grade boards used as a roof deck material. "Step sheathing" is used alone or in combinations with solid sheathing for installation of tiles or shakes. Step sheathing allows air circulations under the tiles by using 1-by-6 or 2-by-6 boards that are evenly spaced so that air can move under the tiles or shakes.
Shed roof: A roof containing only one sloping plane. Has no hips, ridges, valleys or gables.
Single coverage: Asphalt roofing that provides one layer of roofing material over the deck.
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.
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.
Strip shingles: Asphalt shingles that are approximately three times as long as they are wide.