Glossary of Roofing Terms

Asphalt is an organic bituminous compound used in the manufacturing of composition shingles.

Asphalt Roofing Cement
Asphalt Roofing Cement  is used to bond roofing materials. It is also known as flashing cement or mastic.

ASTM American Society for Testing of Materials
ASTM is a voluntary organization concerned with the development of standards, testing procedures, and specifications.  Many city building codes use ASTM Standards.

Base Flashing
Base Flashing is the portion of the flashing that is attached to, or rests on the roof deck.

Blend is the mixture of various colored granules on the surface of shingles.

Blind Nailing
Blind nailing refers to nails driven in such a way that the heads are concealed by succeeding layers of roofing materials.

Blisters are bubbles that may appear on the surface of asphalt roofing.

Bridging is a method of reroofing where the new shingles follow the contour of the old roofing. It is also called “butting up”.

Built-up Roofing
Built-up Roofing is a flat or low sloped roof made up of layers of asphalt and ply sheets.

A butt is the portion of a shingle exposed to the weather. It is sometimes called the “tab” of the shingle.

Cant Strip
A cant strip is a 45 degree beveled wood, fiberboard, or metal strip located at the junction of the roof and a vertical surface used to break a right angle. It is primarily used in low sloped roofing.

Cap Flashing
Cap flashing is flashing installed on a vertical surface to prevent the flow of water from getting behind the base flashing. The cap flashing overlaps the base flashing. This flashing (AKA counter flashing) is generally not replaced in a reroofing job.

Caulk is a substance used to fill a joint or void.

Cement is a substance, when cured, binds two surfaces together.

Class “A”
Refers to the highest fire resistance rating for roofing as per ASTM. Shingles with this rating are designed withstand severe exposure to fire from sources originating outside the building.  Other classes are B and C.

Closed Valley
A closed valley exists when roofing materials cover an entire valley.

A coating is a layer of viscous asphalt applied to shingles in which granules are embedded.

Collars are pre-formed flanges placed over a vent pipe. (AKA as a vent sleeve).

Counter Flashing
See Cap Flashing.

A course is a horizontal section of roofing running the length of a roof.

Dead Level
Dead level refers to a section of roof without any pitch.

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