INDUSTRY COALITION
FORMED TO ADDRESS CHANGES TO FM GLOBAL PROPERTY LOSS PREVENTION DATA SHEET 1-29
In January 2006,
FM Global made significant changes to Property Loss Prevention Data Sheet 1-29
titled “Roof Deck Securement and Above-Deck Roof Components.” The changes
particularly affect the design of fully adhered roofing systems that require a
Class 1-90 rating or higher on steel decks. Fully adhered systems are defined
as hot applied built-up and modified bitumen membranes, torch applied modified
bitumen membranes, cold process built-up and modified bitumen membranes,
self-adhering modified bitumen membranes and single-ply membranes, and
fully-adhered single-ply membranes installed over mechanically-attached
insulation, with or without a cover board, on a steel deck. Before this change,
the requirements for perimeter and corner attachment could be met by simply
increasing the number of fasteners in the perimeter and corner areas for listed
systems.
The newly revised
Data Sheet 1-29 now states that this prescriptive method of increasing the
fasteners in the perimeter and corner areas (bld)cannot be used(endbld) for
fully-adhered roof systems requiring a wind uplift rating of Class 1-90 and
above. Instead, these roofing systems must meet higher tested ratings for the
perimeter and corner areas. No engineering rationale for this change was given,
and very few fully-adhered roofing systems comply with this new requirement.
These changes effectively eliminated the use of the fully-adhered systems
described above requiring a Class 1-90 or higher classification on steel decks
where the system must comply with Loss Prevention Data Sheet 1-29.
In addition, the
newly revised Data Sheet requires the minimum number of fasteners in the
perimeter and corner areas for Class 1-60 and Class 1-75 listed systems to be
increased 50- and 100-per cent, respectively, over the number of fasteners in
the field of the roof. Loss Prevention Data Sheet 1-29 still allows
prescriptive enhancement of perimeter and corner areas for mechanically-attached
membranes, including mechanically-attached base sheets in multi-ply asphaltic
systems. For these systems, the number of fasteners in the perimeter and corner
areas can be prescriptively increased as previously allowed.
These changes were
made without prior notice to the roofing industry. ARMA, CFFA, ERA, NRCA, PIMA,
RCI and SPRI have formed a coalition of interested parties and are considering
ways to address the implications of these changes. The coalition’s goal is to
develop recommendations for wind performance and how it can be properly
accounted for to assist roofing designers, roofing contractors, roof
consultants, property owners, material manufacturers and other interested
parties.
In addition, the
coalition will focus on educating the roofing and specifications community
about the requirements for wind uplift resistance and the determination of
these building code requirements in accordance with the appropriate engineering
standard from the American Society of Civil Engineers, entitled ASCE 7,
(itals)Minimum Design Loads for Buildings and Other Structures.(enditals)
