Built-Up

A roof consisting of multiple piles of roof felts laminated together with bitumen. Built-up roof material can consist of bitumen-saturated felt, coated felt, polyester felt or other fabrics. A surfacing is generally applied and can be asphalt, aggregate (gravel or slag), emulsion or a granule-surfaced cap sheet.

Built-Up Roofing is one of the oldest and most reliable ways of installing a new roof. It was first known as composition roofing and started in the 1840's. B.U.R.'s come in two basic types, asphalt and coal tar, and three basic components:

1. the waterproofing component
2. the reinforcing component
3. the surfacing component which is used to protect the other components from the elements

The roofing membrane is protected from the elements by a surfacing layer, either a cap sheet or gravel embedded in bitumen or a coating material. The most common surface for a BUR system, particularly in the west, is a fiberglass mineral surfaced cap sheet. The west represents 40 percent of the fiberglass cap sheet market. It offers a number of advantages. It has a white granular look, it is cost effective, and is relatively maintenance free.