Plywood diaphragm legth for nailing requirements 1

[F1955]

Thank you in advance for the wisdom. If you have a 6/12 wood truss spanning the N-S direction, would you use the flat horizontal dimension from end to end or the 6/12 top chord horizontal lengths to calculate the required nailing for the diaphragm shear force for the length available to resist the load?

 

[DaveAtkins]

It works out the same either way. If you use the sloped length, you should really take the reaction at the end of the diaphragm and multiply it by (13.4/12), because this gives the equivalent reaction acting on the sloped roof.

DaveAtkins