Algae Discoloration: A type of roof discoloration caused by algae, also called fungus growth.
Attic: The open area above the ceiling and under the roof deck of a steep-sloped roof.
Asphalt Shingle: A shingle manufactured by coating a reinforcing material (felt or fibrous glass mat) with asphalt and having mineral granules on the side exposed to the weather.
Bird stop: In addition to preventing birds from nesting in the hollows of the tile, this length of formed metal or foam elevates the first course of tile so that it is positioned at the same angle as subsequent courses.
Blisters: Bubbles that may appear on the surface of asphalt roofing after installation.
Built-up roof: An outer covering of a comparatively commercial roof, consisting of several layers of saturated felt. As laid, each layer is mopped with hot tar or asphalt. The top layer is finished with a mineral or rock covering and a special coating.
Bundle: A package of shingles. There are generally 3 bundles per square.
Coating: A coat or covering with a layer of any substance, as a cover or protection.
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.
Condensation: The change of water from vapor to liquid when warm, moisture-laden air comes in contact with a cold surface.
Downspout: A pipe for draining water from roof gutters. A downspout is also called a leader.
Exposure: Portion of the shingle exposed to the weather. Exposure is measured from the butt of one shingle to the butt of the next.
Felt: A flexible sheet that is saturated with asphalt and used as an underlayment, sometimes called “tar paper”.
Gutter: The trough that channels water from the eaves to the downspouts.
Lean-to roof: A roof with one slope only that is built against a higher wall.
Life-cycle cost: The total lifetime cost of a roof. Calculated by adding maintenance costs to the installed price, then deducting the added value the roof provides when the home is resold.
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.
Overhang: That portion of the roof structure that extends beyond the exterior walls of a building.
Ply: The number of layers of roofing: i.e. one-ply, two-ply.
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.