by 48Rob » Fri Jan 04, 2013 9:20 am
Ty,
Only you can tell from being there in person if the ply is solid enough...
Pre drill every hole, use good glue, both on the surfaces and in the screw holes, use at least an inch and a quarter of screw thread into the old plywood.
At each roof rib you can add gussets.
Another option is to drill through the old ply, glue in a good size dowel, and then screw the new wood into the dowel, again, predrilled.
You mentioned nails, I wouldn't.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...