What Screws for Solar Panel Bracket to Roof

[dxrobertson]

Will be screwing a 200W solar panel into roof of TPO over 3/8 inch garbage board (OSB).

From researching various solar panel mount options, they all seem to include what I consider "metal screws"- what one would use to screw into metal, as opposed to wood. They have that little tip on the end instead of the screw tapering to a fine point. Pic attached.

Is this what to use for a wood roof? Maybe I am wrong calling these metal screws? I would think a wood screw, about #10 or #12, less than 1 inch long.

[chuckster57]

They are called “self tapping”, and it seems like the factory prefers them in every application. They will grip and tighten, but you’re probably better off with wood screws 1 1/2” long

[fjr vfr]

I used the kind of screws in your picture and they work fine. It makes no difference whether they are wood or metal. They do the same thing.
The screws aren't the only thing keeping the panels in place. Once you have buried them and the brackets with Dicor self leveling compound you'll not see the screws again. So it won't mater what you call them or which kind you used. Out of sight out of mind...lol

[bobbecky]

I'm thinking sheet metal screws, maybe even stainless steel ones. You don't need the drill point on the screw for the wood roof and coarse threads on the screw will give you better holding strength.

[Squanto]

I'd look for a coarse threaded wood screw and might even predrill the holes since it's pressboard.