New Asphalt Slope Guide
Targets Best Selection

D 6510, Standard Guide for Selection of Asphalt Used in Built-Up Roofing Systems will be available May 1 from Committee D08 on Roofing, Waterproofing and Bituminous Materials, to assist specifiers and material manufacturers with selection of asphalt used in built-up roofing (BUR) construction.

The new guide will particularly benefit the BUR industry, says Dick Fricklas, technical director emeritus, Roofing Industry Educational Institute (RIEI), Littleton, Colo., writer, and lecturer. “While BUR roofing is over 100 years old, it continues to represent a third of all low-slope roofing currently installed, and perhaps slightly more in re-cover situations. The guide may also help in the production of a companion guide for modified bituminous (MB) roofing. MB was not included in D 6510, as the waterproofing function is controlled by the MB sheets themselves, whereas in D 6510, the asphalt serves the dual functions of waterproofness and adhesiveness.”

Slope guidelines are listed for the four types of asphalt mentioned in ASTM Standard D 312, Specification for Asphalt Used in Roofing. “Specifiers will find the guide directs them to harder asphalts where there is danger of drippage into the building, such as at roof penetrations and walls, where softer materials might flow,” says Fricklas, a member of ASTM Subcommittee D08.20 on Roofing Membrane Systems. “In considering BUR practice today, glass fiber reinforcements are dominant. Therefore the use of very soft bitumen such as Type I is considered less essential inter-ply, but still may be beneficial as a more durable ‘flood-coat’ than Type III and Type IV.”

Standard Guide D 6510 originated from Appendix X1 of Specification D 312, developed by Subcommittee D08.03 on Surfacing and Bituminous Materials for Membrane Waterproofing and Built-Up Roofing. When a question was raised about the validity of a materials standard containing an appendix on the use of asphalt, the subcommittee sought the assistance of Subcommittee D08.20 on Roofing Membrane Systems, and several members of both parties created the guide as a D08.20 standard.

Among those participating were members of the U.S. Army Corps of Engineers, CERL materials manufacturers, roofing consultants and contractors, Naval Air Force and Command, National Roofing Contractors Association, inspection firms, testing laboratories, asphalt producers, RIEI educators, technical writers, users such as large building owners, and the National Institute of Standards and Technology, Fricklas says.
“It is important for ASTM to help with recommended practices for the use of building technologists,” he continues. “While roofing asphalt is a widely used building material, the only specification available to date has been D 312, which is really only a materials specification. D 6510 is an attempt to summarize the best practices for the use of roofing asphalt, recognizing that there will still be some regional practices which may deviate from those considered in the guide.”

“Hopefully this guide is not the only revision to D 312,” he adds. “Another task force is evaluating changing from the current ring and ball softening point and penetration to viscosity grading of asphalt. This work is progressing and considerable data has been collected.”

ASTM standards are available by calling Customer Service (610/832-9585) or through the Web site.

For further information, contact Dick Fricklas, 8260 E. Geddes Ave., Englewood, CO 80112-1880 (303/773-6014). Committee D08 meets June 18-21 in Toronto, Ontario, Canada during ASTM Committee Week. For meeting or membership details, contact manager Pat Picariello, ASTM (610/832-9720). //