Refer to the following roofing terms & definitions when planning for a new or repaired roof:
Asphalt: A bituminous waterproofing agent applied to roofing materials during manufacturing.
Back Surfacing: Fine mineral matter applied to the backside of shingles to keep them from sticking.
Caulk: To fill a joint with mastic or asphalt cement to prevent leaks.
Closed-cut valley: a method of shingling a roof valley where shingles from one roof plane cover the valley underneath shingles from the other plane, which are cut to fit the valley.
Coverage: Amount of weather protection provided by the roofing material.
Deck/sheathing: The surface, usually plywood or oriented strand board (OSB), to which roofing materials are applied.
Dormer: A small structure projecting from a sloped roof, usually with a window.
Downspout: A pipe for draining water from roof gutters.
Drip edge: An L-shaped strip (usually metal) installed along roof edges to allow water run off to drip clear of the deck, eaves and siding.
Eave: The horizontal lower edge of a sloped roof.
Exposure: The part of roofing material left open to the elements.
Fascia: A flat board, band or face located at a cornice’s outer edge.
Felt/underlayment: A sheet of asphalt-saturated material (often called tar paper) used as a secondary layer of protection for the roof deck.
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.
Fire rating: System for classifying the fire resistances of various materials. Roofing materials are rated Class A, B or C, with Class A materials having the highest resistance to fire originating outside the structure.
Gable: The upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
Granules: Ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
Gutter: The trough that channels water from the eaves to the downspouts.
Laminated shingles – Shingles made from laminating together two separate materials – also known as architectural shingles and dimensional shingles.
Louvers: Slatted devices installed in a gable or soffit (the underside of eaves) to ventilate the space below a roof deck and equalize air temperature and moisture.
Overhang: That portion of the roof structure that extends beyond the exterior walls of a building.
Penetrations: Vents, pipes, stacks, chimneys-anything that penetrates a roof deck.
Pitch: The degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.
Rafters: The supporting framing to which a roof deck is attached.
Rake: The inclined edge of a roof over a wall.
Ridge: The top edge of two intersecting sloping roof surfaces.
Sheathing: The boards or sheet materials that are fastened to rafters to cover a house or building.
Slope: Measured by rise in inches for each 12 inches of horizontal run: A roof with a 4-in-12 slope rises 4 inches for every foot of horizontal distance.
Square: The common measurement for roof area. One square is 100 square feet (10 by 10 feet).
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 angle formed at the intersection of two sloping roof surfaces.
Vent: Any device installed on the roof, gable or soffitt for the purpose of ventilating the underside of the roof deck.