Built Up Roof



Built-up roofing is a term used to describe the process of installing a type of roofing system.

Felt paper measuring 36” wide by 150’ long is rolled out and embedded in either hot asphalt, coal tar pitch, or cold adhesive (types of bitumen). Then, another roll is laid parallel and on top of the first roll 9” from either lengthwise edge, again embedded in asphalt, pitch or adhesive. This process is continued to the edge of the roof. After all of the felts have been laid out, another coating of bitumen will cover the entire roof surface and gravel will be embedded into it. Once completed you will have built-up a roof of four layers of felt paper and five layers of bitumen.

Built-up roofing (BUR) can be used in both new construction projects and on existing buildings. BUR systems have low flexibility and are only appropriate on roof decks with minimal movement or where appropriate expansion joints are provided. BUR systems require periodic maintenance to maximize their service life.