Volume 14, Issue 3 (May 1986)
Measurement of Granule Coverage on Bituminous Roofing Surfaces
Methods were developed to measure the exposed area of bitumen on a granule-covered roofing surface. They included traverse microscopical examination, image analysis technique, and photometric measurements. Three specially prepared samples were tested for granule coverage. One of the samples was further tested for the exposed area of bitumen after progressively removing granules from its surface. The study showed that the exposure of bitumen could be related to the loss of granules.