Plywood Diaphragm Design Values

[ars001]

Here's the question. Table 2306.3.1 in the IBC shows only using 10d nail values with 19/32" panel thickness. If I want to use 8d nails with 19/32" panel thickness, am I allowed to use the values specified with 8d nails and 15/32" panel thickness? For some reason I found something, somewhere that allowed me to do this. Am I right or wrong? Thanks for the help.

 

[msquared48]

You may have seen that circumstance in the Fastening Schedule of Table 2304.9.1, items 31 and 32.

I do not believe that nail size reduction applies for rated shear panel assemblies though, at least I have never seen it.

Mike McCann
McCann Engineering

 

[RARWOOD]

You might be able to us the 8d nails with the 19/32" panels as long as you use the allowable shear values for the 15/32" panel. You would need to check with the APA-EWS to be sure.

I am pretty sure that you could use 8d nails with the 19/32" panel if you determined your allowable shear by principles of mechanics. In some ways your question is similair to the case of nails that are over driven into the panel. In that case you could use the panel thickness under the head as your thickness and calcualte your shear by the principles of mechanics.

On thing to keep in mind, is the actual size of the 8d nails. If the contractor uses a nail gun, the nail will probably be smaller than an 8d nail. As a result your capacity would be lower.