1.1 The purpose of this guide is to provide advice for the selection of asphalt used in the construction of built-up roofing (BUR). This guide does not address the use of asphalt in waterproofing, cold-applied, or modified bituminous roofing.

1.2 Reinforcements considered for use with roofing asphalt include ply sheets, (see Specifications D 226, D 2178, and D 5726), base sheets (see Specifications D 2626, D 4601, and D 4897), and cap sheets (see Specification D 3909). They consist of glass, organic, or synthetic fibers.

1.3 The use of asphalt in the placement of vapor retarders and rigid roof insulation also is addressed.