Nailing OSB sheathing to California code?

Roofing/Construction Questions
#1

I think I expected to nail my 7/16 sheathing 6" OC at the edges and 12" OC at intermediate rafters, but…my city (Anaheim) doesn’t specify what they’re looking for in the permit application, and instead refers back to CBC Table 2304.9.1 (the fastening schedule).

Towards the end of this schedule, in the section talking about Wood Structural Panels and Particle Board, it talks about nailing 4" OC at the edges and 8" OC at intermediate rafters when the sheathing is under 3/4" in thickness (condensing down what it says quite a bit here). Am I reading that correctly? It seems excessive to me, and I know excessive fastening can be a bad thing.

Would it be presumptuous to call the city and find out what the Building Inspector would be looking for? I absolutely want to get this right - if I were to nail 6" OC there is no way I could go back and do 3" - THAT would for sure be excessive nailing.

Another thing is galvanized nails vs. bright. The schedule doesn’t call for galvanized (or at least not that I can see), but I’ve read from other posts that’s what you guys tend to prefer using. The only trouble…I was thinking of going to a 3" nail, on account of having to go through existing spaced sheathing too, but I’m having a dickens of a time finding wire nail coils for my Hitachi gun.

Sorry to be such a newb! I promise you, I have the rest of it pretty much under control.

#2

Call your local inspector.

#3

Your going to want to contact the building dept and ask, Anaheim is notorious for being sticklers. Your better off finding out what they want than doing what you think they want.

#4

Building inspector got back to me today and couldn’t have been more helpful. It is 6" OC edges/12" OC field, as I thought all along. Apparently the other schedule is for new construction where the ply is more integral to the roof’s structure? He also told me that I didn’t necessarily need galvanized nails, on account of all the nails being covered with felt. Which is what I had supposed, but really needed confirmed.

I know you guys like galv for this job, but I could only find those in a 3.25" / .131 shank for my gun, which I thought was a bit on the long side. I’ve settled on 3" / .131 brights (remember I have to nail through skip sheathing and the 7/16" OSB). Interestingly, while I figured the city would want something like 1.5" of nail penetration into the rafter, the inspector told me they only look for 3/4" (I still think that’s a bit skinny, what with the Santa Ana winds we get round here in autumn). He did tell me though that using more nails than code calls for is not necessarily a bad thing! :biggrin:

So back on track and ready to move forward, methinks!