SDI Recognized #12 Screws with PLB-36 Roof Deck
When Verco’s PLB-36 deck is to be screw fastened to supports, it shall be with minimum SDI Recognized (Buildex, ELCO, Hilti or Simpson Strong-Tie) #12 self-drilling, self-tapping screws with hex washer heads. The diaphragm shear and flexibility values shown in Verco’s evaluation report and on pages 44-47 of VR3 (Link Dead) assume minimum 54 mil (16 gage, or 0.0566 in.) cold-formed steel supports with minimum Fy = 33 ksi (Fu = 45 ksi). These shear and flexibility values may be modified for supports with different thickness and/or material strength using the adjustment factors shown in the evaluation report and catalog.
See the table below for suggested screw selection based on actual substrate thickness.
Suggested Screw Selection
- 33 mil (0.0346″) to 3/16″
- 1/8″ to 1/4″
- 1/4″ to 1/2″
- #3 Drill Point
- #4 Drill Point
- #5 Drill Point
The spacing of screws at collectors or drags parallel to the deck ribs should be based on the shear force to be transferred. Allowable shear strengths for #12 screws with various gage decks can be found in Verco’s evaluation report and catalog.