Built Up Roofing
A built up roofing (Smooth Built-Up, Ballasted Built-Up, or Tar and Gravel) is a class of low-slope roof that consist of laying down several layers of tar and water resistant materials and then covered with gravel.
Many old buildings with low slope or flat roofs are topped with built-up roofing made from layers of asphalt-coated roofing felt. The top layer is usually covered with rock or gravel, which serves as a ballast to hold the roofing material down and protect it from UV damage. Built-Up Roofs with gravel surfacing are also known as Tar and Gravel roofs. Typical life span of a built-up roof is 10 to 20 years depending on weather conditions.
Built up roofing is the most popular material used on low-slope roofs. A built-up roofing, is composed of several layers of bitumen surfaces, and finished up with an aggregate layer or coating. Recent built-up products incorporate a rigid insulation layer as part of the built-up roofing. The fabrics or layers used on built-up roofing are called ply sheets. These sheets are commonly reinforced with fiberglass mats or organic mats, depending on their application. Ply sheets are commonly produced in a standard size about 36 inches width.
Pros and Cons of Built Up Roofing
•It provides excellent waterproofing protection.
•Built-up Roofing provides ultra-violet protection.
•It lasts longer to weather inclemency
•Gravels or minerals can be used as surfacing material.
•Low-life cost maintenance
• Hazard fumes and vapors when installing it.
• High installation costs.
•Susceptible to wind and water damage.