Wood Nailing Strips
All non-nailable decks require pressure-treated wood nailing strips to be specified at eaves, edges, walls, roof-openings, etc. for proper securement of metal flanges. Nailers must be securely and firmly attached to the deck or through to its supporting members. Nailers shall extend not less than 1" (25mm) beyond the apron or flange. Wood treatment shall be suitable for use with the roofing membrane systems.

Good roofing design indicates that the following points be considered when specifying wood nailers:
  1. Wood nailer design should comply with Factory Mutual Loss Prevention Data Sheet 1-49.
  2. Where insulation is used and/or on non-nailable decks, when wood nailers are required, they must be specified in such a manner that the upper surface is flush with the surface to which the roofing membrane is to be applied. These wood nailers shall be a minimum of 2" (51mm) wide and thick enough to receive the fastener or the thickness shall be the same as the insulation, whichever is greater. All wood nailers shall be effectively attached to their substrate.
  3. Where wood nailers are required, specify their location to be perpendicular to (across) the roof slope with nailers on both sides of the ridge and at the roof system high points. Ridge and high point nailers shall be a nominal 4 inches (102mm) wide, or more.
  4. For asphalt specifications, on slopes 2 inches to 3 inches per foot (16.7% to 25%), nailers shall be specified approximately 4 feet (1.22m) apart.
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