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.