Quote Originally Posted by Irving View Post
I'm not saying that a metal roof will leak, because not all of them will. Any rubber on fasteners will wear out long before the roof though. In general, the more cut up a roof is, the more possibility of leaks, regardless of the material.
True. More angles = more places to leak.

I was in a building for a while that had a 120 year old metal roof. That thing leaked like a sieve. Leaked at several nail holes. I doubt it ever had rubber washers on the nails or any tar paper.