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 NJ contractor since 1994, and a father, and husband. Contact me for all your construction questions.

Thursday, December 30, 2010

Lets talk terms and definitions

Asphalt:  A bituminous waterproofing agent applied to roofing materials during manufacturing.
Asphalt plastic roofing cement:   An asphalt-based cement used to bond roofing materials. Also known as flashing cement or mastic.
Blisters:  Bubbles that may appear on the surface of asphalt roofing after installation.
Build Up Roof:  A flat or low-sloped roof consisting of multiple layers of asphalt and ply sheets.
Bundle:  A package of shingles. There are 3, 4 or 5 bundles per square.
Butt edge:  The lower edge of the shingle tabs.
Caulk:  To fill a joint with mastic or asphalt cement to prevent leaks.
Chalk line:  A line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment purposes.
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.
Condensation:  The change of water from vapor to liquid when warm, moisture-laden air comes in contact with a cold surface.
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.
Coverage:  Amount of weather protection provided by the roofing material. Depends on  number of layers of material between the exposed surface of the roofing and the deck; i.e., single coverage, double coverage, etc.
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.
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.
Eaves 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 re-roofing with asphalt shingles.
Fiber glass mat:  An asphalt roofing base material manufactured from glass fibers.
Flashing:  Pieces of metal 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. Galvanized metal flashing should be minimum 26-gauge.
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. Contains 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.
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.
Laminated Shingles:  Strip shingles containing more than one layer of tabs to create extra thickness. Also called three-dimensional shingles.
Lap:  To cover the surface of one shingle or roll with another.
Low Slope Application:  Method of installing asphalt shingles on roof slopes between two and four inches per foot.
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.
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 quarter unless otherwise specified.
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 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.
Ridge:  The uppermost, 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.
Run: The horizontal distance from the eaves to a point directly under the ridge. One half the span.
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.
Soffit:  The finished underside of the eaves.
Square:   A unit of roof measure covering 100 square feet.
Starter:  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.
Tab:  The exposed portion of strip shingles defined by cutouts.
Three Tab Shingle:  The most popular type of asphalt shingle usually 12" x 36" in size with three tabs.
Top lap:  That portion of the roofing covered by the succeeding course after installation.
Underlayment:  A layer of asphalt saturated (sometimes referred to as tar paper) which is laid down on a bare deck before shingles are installed to provide additional protection for the deck.
Valley:  The internal angle formed by the intersection of two sloping roof planes to provide water runoff.
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