| Aggregate |
(1) crushed stone,
crushed slag or water-worn gravel used for surfacing
a built-up roof. (2) any granular mineral material.
|
| Alligatoring |
the cracking
of the surfacing bitumen on a built-up roof, producing
a pattern of cracks similar to an alligator's hide;
the cracks may or may not extend through the surfacing
bitumen. |
| Ambient Temperature |
temperature of air - - air temperature. |
| Application Rate |
the quantity (mass, volume or
thickness) of material applied per unit area. |
| Area Divider |
a raised, double wood member
attached to a properly flashed wood base plate that
is anchored to the roof deck. It is used to relieve
thermal stresses in a roof system where no expansion
joints have been provided. |
| Asbestos |
a group of natural, fibrous,
impure silicate materials. |
| Asphalt |
A dark brown to black material
in which the predominating constituents are bitumens,
which occur in nature or are obtained in petroleum
processing. |
| Asphalt, Air Blown |
an asphalt produced by blowing
steam through molten asphalt to modify its properties,
normally used for highway bitumen. |
| Atactic Polypropylene |
a group of high molecular weight
polymers formed by the polymerization of propylene. |
