Algae discoloration is a type of roof discoloration caused by algae. Commonly, but inaccurately, called fungus growth. Usually it is dark brown to black in color.

Algae Resistant Shingles are shingles, which coated with copper granules on the weather side to prevent the formation of algae and the resultant discoloration.

Algicidal Treatment is a method of cleaning discolored shingles with a bleach mixture to lighten the discoloration caused by algae formation.

Asphalt is a bituminous waterproofing agent applied to roofing materials during manufacture.

Asphalt roofing cement is an asphalt-based cement containing solvent, used to bond roofing materials. Also known as asphalt plastic cement, flashing cement, muck, bull, or mastic.


Cap flashing is the portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.

Caulk means to fill a joint with mastic or asphalt roofing cement, or the material used to fill the joint.

Certificate of Compliance is a certificate indicating that shingles meet their appropriate standards.

Chalk line defines a line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment purposes.

Closed-cut valley is a method of valley treatment in which shingles from one side of the valley extend across the valley, while shingles from the other side are trimmed 2″ from the valley centerline. The valley flashing is not exposed.

Coating Asphalt is a layer of asphalt applied to the base reinforcement material into which granules or other surfacing is embedded.

Collar defines a pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Collar is also called a vent sleeve.

Condensation defines the change of water from vapor to liquid when warm, moisture-laden air meets a cold surface.

Course is a horizontal row of shingles or roll roofing running the length of the roof.


Deck defines the surface installed over the supporting framing members, to which the roofing is applied.

Diagonal method is a roofing application method in which shingles are applied diagonally up the roof.

Dormer is a framed window unit projecting through the sloping plane of a roof.

Double coverage defines the application of asphalt roofing such that the lapped portion is at least 2″ wider than the exposed portion, resulting in two layers of roofing material over the deck.

\Downspout is a pipe for draining water from roof gutters.

Drip edge is a corrosion-resistant, non-staining material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.


Eaves flashing is an additional layer of roofing material applied at the eaves to help prevent damage from water back up.

Exposure defines the portion of the roofing exposed to the weather after installation, usually expressed in inches.


Fascia is a flat board, band, or face located at a cornice’s outer edge.

Feathering strips means tapered wood filler strips placed along the butts of old, wood shingles to create a level surface when re-roofing over existing wood shingle roofs.

Felt is an organic fiber mat impregnated with asphalt and used as an underlayment.

Fiberglass mat is a reinforcing material for asphalt roofing manufactured from glass fibers.

Fiber Glass Shingles are asphalt shingles made with a fiberglass mat.

Flashing are 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.


Gable is the upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof

Gable roof is 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 is 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.

Granules– Ceramic-coated, colored crushed rock that is applied to the exposed surface of asphalt roofing products.

Gutter is the trough that drives water from the eaves to the downspouts.


Ice dam defines condition formed by the thawing and refreezing of melted snow, especially at the lower roof edge on the roof overhang and in gutters. Can cause water to pond and flow up and under shingles, causing leaks.


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


Nesting defines 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.


Open valley is a 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.

Overhang is the portion of the roof structure that extends beyond the exterior walls of a building

Overlay Shingle is a one-piece base shingle to which overlay pads, consisting of an additional layer of asphalt and granules are applied in random patterns to simulate two-piece laminate shingles.


Patterning defines the formation of various geometric designs or patterns on the roof resulting from overlay- or laminated tab-type shingles applied incorrectly or from incorrect color blends.

Racking is a roofing application method in which shingle courses are applied vertically up the roof.


Rafter is the supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.

Rake is the inclined edge of a sloped roof over a wall.

Ridge is the uppermost, horizontal external angle formed by the intersection of two sloping roof planes.

Ridge shingles are used to cover the horizontal external angle formed by the intersection of two sloping roof planes.

Roll roofing defines asphalt-roofing products manufactured in roll form.


Saturated felt in an asphalt-impregnated felt used as an underlayment between the deck and the roofing material.

Scuffing is damage produced to the shingle surface, usually the granules or top coating layer, caused by foot traffic or by placing objects on newly installed shingles.

Self-sealing shingles contains factory-applied strips of self-sealing adhesive.

Self-sealing strip– factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.

Sight Card is a cardboard geometrical shape used to determine roof slope from the ground.

Slope defines the degree of roof incline expressed as the ratio of the rise to the run, in inches.

Soffit– the finished underside of eaves.

Soffit Vents are vents located under the eaves provide air intake. They should be used together with other higher elevation vents.

Soil stack is a vent pipe that penetrates the roof.

Starter strip is 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. It also provides for sealing down of tabs of the first course of self-sealing shingles.

Step flashing is a base flashing application method used where a vertical surface meets a sloping roof plane. Utilizes multiple pieces of flashing material.

Stickering is the process of inserting spacers between deck panels before installation in order to allow them to reach a more natural moisture content and dimension.

Strip shingles are asphalt shingles that are approximately three times as long as they are wide.