Plywood on roofing now?

[tikicarver]

Does anybody know why the county is requiring plywood sheathing on roofs now? Is it a structural thing? I read the code and can’t find it anywhere. I figured I’d ask here before calling the county directly. Thanks in advance.

If you get a engineer stamp on your plans you can go w/o the plywood and 4' OC rafters

I don't know if that will work with the building permit dept.
I am building a garage, I had planned to build the roof just like  all the metal post frame buildings on the mainland.There are tons of Youtube videos about building them and lots of company's selling plans etc. They all build the roof the same basic way.
trusses, with purlins then put the metal roof panels directly on top. the metal roof panels are thick enought to handle the sheer loads required. You just have to get the truss and purlin sizes calculated correctly for the dimensions of your building.

But when I talked to the building dept in Hilo, they said " plywood decking is required."  Even after I pointed out that the code says decking is not required if the metal roof panels are rated to handle the sheer load. I figured it was not worth arguing with them and just went with the plywood, since I would have to convince the guy who drew the plans too..

This is the same building dept that would not approve my plans when I had no electircal planned. One guy kept saying I need to have an electircian on the declaration sheet. I told him there is no electircal, it says it on the plans and they were stamped approved. He kept saying code requiires electical installed.  I ended up having to go in person to the office with copies of the code in hand to prove to them there is no code requirement for installing electical in a detacted garage. the guy was misreading the code that said 'IF you install electical, there must be a min of one branch circuit with 2 outlets". Luckly there were 2 other guys there that day that said the first guy was wrong and the signed off my permit.   I don't think it would be that easy trying to get them to approve no plywood,, because everyone is doing it.

but once again they are not reading the code correctly or don't understand the engineeering.  There are 1000s of post frame buidings on the mainland with the roof and the siding just metal panels on trusses, purlins and girts. the metal panel IS THE sheer strength of the budiling. and they withstand huricanes....