SPRI would like to thank NRCA's Associate Executive Director of Technical Services Mark Graham for his March column, "Specifying wind design," page 16. We at SPRI believe he did a good job clarifying code requirements regarding wind design of low-slope roof systems for the roof field and edge.
We would like to clarify it is the ANSI/SPRI ES-1, "Wind Design Standard for Edge Systems Used with Low-Slope Roofing Systems," test methods that are referenced in the International Building Code (IBC) and not the ANSI/SPRI ES-1 load calculations. Graham is correct in stating ANSI/SPRI ES-1 calculations are based on ASCE 7-02, "Minimum Design Loads for Buildings and Other Structures," and that IBC 2012 requires loads to be calculated using ASCE 7-10 as required in Chapter 16. It should be noted the ANSI/SPRI ES-1 test methods do not refer to or otherwise cover load calculations. SPRI would like to point out Section 1504.5 of IBC 2012 also requires perimeter edge metal be tested per ANSI/SPRI ES-1.
SPRI believes that in addition to documenting the design wind loads for roof edges in contract documents, as Graham states, the fabricator or supplier of the edge metal system should provide documentation that the roof edge has been tested according to ANSI/SPRI ES-1 and has been found to be in code compliance to resist those design loads.