Asphalt - A bituminous waterproofing agent applied to the roofing materials during manufacturing.

Blisters - Bubbles that may appear on the surface of asphalt shingles.  Usually due to improper ventilation.

Deck (Decking) - The surface to which the shingles are applied. Common types of decking are plywood and wood shingles.

Downspout - A pipe for draining water from roof gutters.  Also called a leader.

Drip Edge - A non-corrosive, non-staining material used around the perimeter of the roof to allow water to run off clear of underlying structures.

Eaves - The horizontal, lower edge of a sloped roof.

Facia - The vertical face board of eaves.

Felt - Fibroud material saturated with ashpalt and used as a underlayment or sheathing paper.

Flashing - Pieces or a roll of metal used to direct water away from the adjoining walls, vent pipes and chimneys.

Ice Dam - Condition formed at the lower roof edge by the thawing and re-freezing of melted snow on the overhang.  Can force water up and under shingles, causing leaks and water damage.

Laminated Shingles - Strip shingles containing more than one layer of tabs to create an extra thickness.  Also called three-dimensional shingles or architectural shingles.

Open Valley - Method of valley construction in which shingles on both sides of the valley are trimmed leaving flashing exposed.

Pitch - The degree of roof incline expressed as the ratio of rise over span in feet.  E.G. 2/12 is extremely level, 12/12 is steep.

Ridge - The point where two roof planes meet.

Roll Roofing - Asphalt roofing manufactured in roll form.

Seal Tab - Factory-applied adhesive that bonds individual shingles together when exposed to the heat of the sun.  (Note: After five (5) years, once a seal tab is broken it will not re-adhere.)

Soffit - The finished underside of eaves.

Square - A measurement unit meaning 100 square feet.

Starter Strip - A special asphalt strip applied along the perimeter of the roof to seal the first layer of shingles to the roof.

UL - Underwriters Laboratories Inc.  An organization that tests and rates various products.

Valley - The internal angle formed by the intersection of two sloping roof planes.

Vent - Any outlet for air that protrudes through the roof deck such as a pipe or stack.  Any device installed on the roof for the purpose of ventilating the attic.