Rusty Roof

[Durian Fiend]

With the screws, eventually the rusted heads will shrink in size and you will not be able to remove them easily with a screw gun. Although stainless aren't necessary they are a safe bet.

I've had non stainless screws that have lasted for a couple decades and others that have completely rusted out in less time. Depends on how they are coated, I guess.

With the roof panels you could always reverse the direction of them and put the good end as the new drip line, after pulling them up and treating the rusty edge.