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
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
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). //