In January, FM Global significantly revised its Property Loss Prevention Data Sheet 1-29, "Roof Deck Securement and Above-Deck Roof Components." This data sheet is intended to provide FM Global's recommendations for securement of roof decks to roof structures and the proper design and installation of above-deck roof components (insulation, membrane). You need to be aware of the revisions because they may affect roof system design and limit the use of some products and systems.
Previous editions of FM 1-29 included a prescriptive option for increasing attachment of mechanically fastened rigid board insulation at the roof perimeter and corners where design wind-uplift pressures are recognized to be greater than in the field of the roof area.
For example, in the 2003 edition of FM 1-29, roof perimeter attachment was recommended to be increased 50 percent and roof corner attachment 75 percent from the roof field attachment pattern to account for these wind-uplift pressures.