From Wind Mitigation Course:
“An example* of a multiple deck is shown in the picture. Look for signs that the missed fastener is used to secure the outermost layer of decking and not just the first layer of decking. A multiple layered deck should be considered to be standard attachment, regardless of fastening schedule.”
I have seen this scenario multiple times. An older home with original batten decking that likely had a wood shake roof at one time. The house now has plywood decking installed over the entire roof system with a shingle roof. The spacing of the original batten decking fasteners is beyond 6". Now the new plywood decking is installed, but into the batten boards and not necessarily with the intention of getting into the rafters.
I did work with an engineer once on one of these old homes in our area and he and I determined that the fastening of this scenario at the particular home, I was inspecting, did not meet the uplift resistance of 8d at 6".
What does the course mean when it says: “A multiple layered deck should be considered to be standard attachment, regardless of fastening schedule.”…?
Standard attachment…?
Thoughts on these types of scenarios?
Thx!