| Term | Description |
|---|---|
| Ballast | A material, such as minimum nominal #1-1/2 inch size or #4, or alternatively, #3, #24, #2 or #1—as specified in ASTM D448—smooth river stone, crushed stone, standard precast concrete pavers or interlocking, beveled, doweled or contoured fit lightweight concrete pavers, that employs its mass and the force of gravity to hold a roof membrane system in place. |
