Dimensional lumber decks are typically stronger than plywood/OSB roof decks because they are attached with more nails than plywood/ OSB decks. Thus, even older homes built before the introduction of high-wind criteria into the local building codes may qualify for wind insurance credits.
The roof deck connection type can be determined on existing buildings by using a metal detector to locate the nails or screws. The following is the type of deck connections for which insurance companies may give credits.
The following items describe the typical roof deck attachment methods used in residential construction. Each of the nail options refers to the size of the nail (commonly referred to as a penny size (d)) and the spacing of nails along the framing members. The two numbers refer to the spacing along the edges of the plywood and the spacing of nails along the interior members of the plywood.
8d Nails @ 6/6 - Roof deck is attached with 8d (2.5" long) nails spaced at 6 inches on the edge of the sheathing and the interior of the sheathing. This connection pattern is seen mostly in newer homes built to high wind standards.
Screws/Bolts - Instead of using nails to attach the deck, some manufacturers are now producing screw guns that can install screws almost as fast as nails. Screws typically have must greater pullout resistance than equivalent lengths of nails.
8d Nails @ 6/12 - Roof deck is attached with 8d (2.5" long) nails spaced at 6 inches along the edge of the sheathing and 12 inches in the interior of the sheathing.
6d Nails @ 6/12 - Roof deck is attached with shorter 6d (2" long) nails spaced at 6 inches along the edge of the sheathing and 12 inches in the interior of the sheathing. please contact me for further Information
visit our web: http://www.es-insurance.com/