American Architectural Manufacturers Association

The act or process of retaining foreign particles such as gas or liquid without transmission of these particles.

American Concrete Institute

(1) The use of a strong acid to remove the surface of concrete thereby exposing the aggregate. (2) The use of a strong acid to etch the surface of material such as metal in order for that material to accept a primer or Spray Polyurethane Foam.

American Council of Independent Laboratories

A coating system with an acrylic resin base.

Polymers of acrylic or methacrylic monomers often used as a latex base for coating systems.

Will corrode in the presence of moisture or a "noble" metal.

The clinging of one surface to another; either molecularly or otherwise.

Associated General Contractors of America

A surfacing or ballast for a roof system. Aggregate can be rock, stone, crushed stone or slag, water-worn gravel, crushed lava rock or marble chips.

A type of roof discoloration caused by algae, also called fungus growth.

Alligatoring is term used to describe the cracking of surfacing bitumen on a built-up roof. These cracks are the result of the limited tolerance of asphalt to thermal expansion or contraction, and produce a pattern that resembles an alligator's hide.

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 weather.

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