I've got a flat(ish) garage roof made of box profile metal sheets which are held down to the OSB underneath using specific screws with big hexagonal h eads and a metal washer with a rubber washer underneath.
Anyway, I had to remove a couple of screws and put them in again a few inch es away and so needed to fill the hole that was left. I used epoxy putty an d I'm wondering if this is likely to last or, if not, what is the best alte rnative way of filling the hole?