In September, FM Global issued another revision to its Loss Prevention Data Sheet 1-29, "Roof Deck Securement and Above-Deck Roof Components." This latest revision, which is actually dated August 2007, follows other revisions that took place in February, May 2006 and January 2006.
If you are involved in roof assembly design and installation where FM Global's guidelines apply, I encourage you to be familiar with the latest revisions to FM 1-29.
FM Global has returned to allowing its prescriptive perimeter and corner fastener enhancements for Class 1-90 but only in limited situations. Since the January 2006 revision, prescriptive perimeter and corner fastener enhancements only have been permitted by FM Global up to Class 1-75. With the latest revision, for buildings located in non-hurricane-prone regions, prescriptive enhancements are permitted in areas where the roof rating's recommended field does not exceed Class 1-90.