Fastener "Rules of Thumb" for Major Applications
Subfloor
Screw spacing should be 6" o.c. at the boundaries and 12" o.c. in the field, assuming an unblocked diaphragm. For blocked diaphragms increase the numbers of screws by 15%.
Deck
Typically two screws at each deck board/joist intersection, approximately 300-400 screws per 100 square feet depending on joist spacing.
Drywall
Approximately 34 screws per 4x8 sheet.