SPRI, the association representing sheet membrane and component suppliers to the commercial roofing industry, has announced that “The Wind Design Standard Practice for Roofing Assemblies ANSI/SPRI WD-1” has been updated and accepted as an American National Standard as of December 2008 after the removal of permissive language.

SPRI, the association representing sheet membrane and component suppliers to the commercial roofing industry, has announced that “The Wind Design Standard Practice for Roofing Assemblies ANSI/SPRI WD-1” has been updated and accepted as an American National Standard as of December 2008 after the removal of permissive language. This Wind Design Standard Practice is the work of several industry partners and provides a two-part methodology of designing for wind uplift resistance of non-ballasted built-up roofing, modified bitumen, and single-ply roofing system assemblies installed over any type of roof deck. (Refer to the ANSI/SPRI RP-4 Standard for wind design requirements of ballasted single-ply roofing systems). This standard was originally approved as an ANSI standard in 2007. The recent changes removed permissive language, which would prevent the standard from being accepted into building code.

“This wind design standard provides an excellent tool to assist architects and consultants with the design and installation of roof systems that are compliant with the wind resistance requirements of the International Building Code (IBC),” said SPRI Technical Director Mike Ennis. “This standard contains easy-to-read tables that were developed using the calculations contained in ASCE-7, as required by the IBC. This standard also contains prescriptive enhancements that can be used under defined conditions for the perimeter and corner areas of the roof.”

RP-4 wind standard re-approved
SPRI also announced that “The Wind Design Standard Practice for Roofing Assemblies ANSI/SPRI RP-4” has been accepted as an American National Standard as of December 2008. This standard, which was approved in 1997, revised and re-approved in 2002, and again in 2008, is intended as a reference for those individuals who design, specify, and install ballasted single-ply roofing systems. As required by the American Standards Institute policy, all National Standards must be re-evaluated every five years.

In other news, SPRI plans to reaffirm ANSI/SPRI RD-1-2003 Performance Standard for Retrofit Drains. This standard, which was approved in 2003, is intended as a reference on retrofit roof drains, which are designed for installation in existing drain plumbing on existing roofs. Interested parties may participate in the retrofit drain canvass by contacting SPRI at 781-647-7026, or via email at info@spri.