Built-up roofing, often referred to simply as BUR, is a type of membrane roof that consists of alternating layers of bitumen and fabrics for reinforcement. In most cases, the construction of a built-up roof starts with fastening a bottommost base sheet on the deck, but built-up roofs can be constructed without the base layer as well.

The bitumen most commonly used in built-up roofs is asphalt, cold-applied adhesive or tar, while the fabrics used between the layers of bitumen are usually made from roofing felt reinforced with organic or glass-fiber mats. During the building procedure, the bitumen is heated in some sort of tanker, then it is applied on the roof surface with the help of a mechanical spreader device, such as a mop. Each layer of bitumen is followed by a layer of felt until the desired thickness is achieved, after which the roof is covered in some sort of finishing material, such as gravel or mineral granules for improving the durability of the roof.

When purchasing a new BUR, there are two types of warranties that you need to consider: the manufacturer’s warranty that covers material defects and the warranty offered by the commercial roofing CT technician who performs the installation on the labor. When the roofing project is complete, it is recommended to obtain both documents.