Roofing Terminology

Well over 100 terms are typically utilized in the roofing industry. It’s always a good idea to become familiar with basic terms in order to better understand your roofer’s explanations. Here is a list of some of the most common terminology.

Aggregate: Loose surfacing material or ballast for a roof system.

Back surfacing: Fine mineral matter applied to the back side of shingles to keep them from sticking.

Base flashing: The portion of the flashing that directs the flow of water onto the roof covering.

Battens: 1" x 2" x 4' wood strips nailed to the roof.

Bundle: A package of shingles. There are 3 to 5 bundles per square (see square).

Caulk: To fill a joint with mastic or asphalt cement to prevent leaks.

Class "A": The highest fire-resistance rating for roofing

Concealed nail method: Application of roll roofing in which all nails are driven into the underlying course of roofing and covered by a cemented, overlapping course. Nails are not exposed to the weather.

Course: A row of shingles or roll roofing running the length of the roof.

Coverage: Amount of weather protection provided by the roofing material, i.e., single coverage, double coverage, etc.

Deck: The surface installed over the supporting framing members to which the roofing is applied.

Dimensional shingle: a shingle that is textured, overlayed, or laminated and designed to produce a three-dimensional effect.

Fascia: Horizontal trim at the eaves that covers the rafter ends.

Flashing: Pieces of metal or roll roofing used to prevent seepage of water into a building around any intersection or projection in a roof.

Interlocking shingles: Shingles that mechanically fasten to each other to provide wind resistance.

Laminated shingles: Strip shingles containing more than one layer of tabs to create extra thickness.

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.

Nesting: A method of re-roofing with new asphalt shingles over old shingles.

Non-prorated warranty: A warranty which provides full replacement costs for covered items.

Organic shingle: An asphalt shingle reinforced with organic cellulose fibers.

Pitch: Also known as "slope", pitch is the measure of how "steep" a roof is.

Prorated warranty: A prorated warranty reimburses a percentage of replacement costs, depending on the age of the roof.

Rake: The inclined edge of a sloped roof over a wall from the eave to the ridge.

Ridge: The uppermost, horizontal external angle of the roof

Rise: The vertical distance from the eave line to the ridge.

Soil stack: A vent pipe that penetrates the roof.

Span: The horizontal distance from eaves to eaves.

Square: A unit of roof measure covering 100 square feet. Roofing prices are often provided per square.

Tear off: Removing an existing roof system.

Telegraphing: A shingle distortion that may arise when a new roof is applied over an uneven surface.

Underlayment: A layer of asphalt which is laid down on a bare deck before shingles are installed.

For additional terms, an excellent compendium of roofing technology may be found on the Owens Corning Web Site, or ask one of our roofing contractors.