What is the minimum nail penetration depth through the plywood deck?

The minimum nail penetration depth through the plywood deck typically needs to be sufficient to ensure that the nail adequately secures the materials being fastened and does not risk withdrawal under load. The correct choice of a minimum of 1/8 inch penetration allows for the necessary holding power while also considering that any less penetration may not provide enough grip, leading to potential issues with the assembly strength and performance of the roofing system.

This choice aligns with common building codes and industry standards, which often specify similar minimum penetration depths to ensure the structural integrity of roof assemblies. A higher penetration depth, such as 1/4 inch or 1/2 inch, could be appropriate in certain scenarios, depending on the application, but the minimum requirement is often set at 1/8 inch to ensure a balance of strength and efficiency in fastener use.