Exposure B: Ground is covered with numerous, closely spaced obstructions within ½ mile of building location.
Exposure C: Terrain is flat and generally unobstructed extending 1/2 miles (.81 KM) or more from the site in any quadrant
Exposure D: Terrain is flat and unobstructed extending 1 mile (1.62 KM) from building location in non-hurricane regions.
Single-ply - Consist of a flexible membrane that resists displacement by the use of ballast, mechanical attachment, or adhesion to a roof deck (EPDM, PVC).
Built-Up - Build-Up-Roofs (BUR) are multiple layers of felt with inter-ply mopping of asphalt or coal tar assembled in the field to "build up" a finished roof assembly. A heavy application of asphalt or coal tar, which is then covered with gravel, is the typical surface finishing to these assemblies, primarily for fireproofing and ultra violet protection.
Metal Roof -Typically steel, aluminum or copper metal roofing. Most metal roofs are installed in sheets, but can also be installed in shingles, the most popular being aluminum or copper.
Foam Roof over a metal or concrete deck.
Ground Mount
Other (please describe)