I would like to put 10 inch foam on my roof with OSB on top but where do I find 12 inch screws?  I suppose if I could find 12 inch screws for metal roofing I could foreget the OSB. I want to put 4 inch foam on the walls so where do I get 5 or 6 inch nails to put the vinyl sideing on?

Go to a comercial roofing supply co. for screws. Nails would be a problem, as nails get longer the diameter increases.

Thanks Smartwall I will try there.