Commonly known as tar & gravel roofs they have been around for over a hundred years. They are composed of alternating layers of bitumen and reinforcing fabrics to create a finished membrane. The bitumen used can either be hot asphalt, coal tar or cold applied adhesive. Surfacing can either consist of aggregate or glass fiber and mineral surfaced cap sheets. Built-Up roof systems are extremely durable and are known to last much longer than single-ply roof systems. Prime installs products from most of the top manufacturers of these systems. We own all of our own kettles and are one of the few installers still able to perform these roof systems in our area.