Glossary of Common Roofing Terms

Glossary of Common Roofing Terms

Get ready for your next roofing project…below you will find the most common terms associated with residential roofing.

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

Caulking – The physical process of sealing a joint or juncture, or sealing and making weather-tight the joints, seams or voids between adjacent surfaces by filling with a

Deck/sheathing: The substrate over which roofing is applied. Usually plywood, wood boards, or planks.

Dormer: A small structure projecting from a sloped roof, usually with a window.

Drip Edge: An installed lip that keeps shingles up off the deck at edges, and extends shingles out over eaves and gutters, and prevents.

Eaves: The roof edge from the fascia to the structure’s outside wall. In general terms, the first three feet across a roof is termed the eave.

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

Flashing: Pieces of metal used to prevent the seepage of water around any intersection or projection in a roof system, such as vent pipes, chimneys, valleys and joints at
vertical walls.

Gable Roof: Traditional roof style – two peaked roof planes meeting at at ridge line of equal size.

Hip Roof: A roof with four roof planes coming together at a peak and four separate hip legs.

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.

Open Valley: A valley where the flashing is exposed to the weather.

Oriented Strand Board (OSB): Roof deck panels (4 by 8 feet) made of narrow bits of wood, installed lengthwise and crosswise in layers and held together with a resin glue. OSB
often is used as a substitute for plywood sheets.

Rafters: The supporting framing to which a roof deck is attached.

Racking: Method of installing shingles in a straight up the roof manner.

Rigid Vent: Hard plastic ridge vent material.

Roof Louvers: Rooftop rectangular shaped roof vents. Also called box vents, mushroom vents, airhawks, soldier vents.

Sheathing: The boards or sheet materials that are fastened to rafters to cover a house or a 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.

Soffit: A board or sheet that extends from the fascia to the buildings siding and hides the bottom of an overhang. Soffit may or may not contain ventilation slots depending
on the attic venting system used.

Square: The common measurement for roof area. One square is 100 square feet (10 by 10 feet).

Truss: Engineered components that supplement rafters in many newer homes and buildings.

Underlayment: Asphalt-based rolled materials designed to be installed under main roofing material to serve as added protection.

Valley: Area where two adjoining sloped roof planes intersect on a roof creating a “V” shaped depression.

Vapor: A material designed to restrict the passage of water vapor through a roof system or wall.


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