JackStraw wrote
Also, I would imagine anything metal in the tropics is just a nightmare due to the humidity...wouldn't a steel roof rust extremely quick? My friend brought his super titanium alloy or whatever it is called bicycle over from Italy. He had that thing sitting in his attic over there for over 10 years and looked brand new when it came to Bali.
2 years later the thing is all messed up due to the humidity.
If I'm wrong, please let me know. I'm very curious about this topic as well
I lived in Darwin, northern Australia, for many years, a few degrees south of Bali's latitude, probably hotter and more humid, and steel roofs were the only roofs when I lived there, tiles being too susceptible to lifting in high winds, and it was a cyclone/typhoon zone.
I think you could comfortably expect 25+ years from a colourbond, or zincalume, roof in Bali.
If the pitch is too low, tiles are a real problem, particularly in high winds capable of driving rain up under them, but with sarking, even that shouldn't be a problem, and Bali doesn't get high winds, being in the doldrums, close to the equator.
