You do not want a metal roof directly on shingles. The expansion and contraction will wear the finish off the bottom of the sheet leading to it rusting. I was also told it will void the warranty with almost every metal supplier.

A metal roof for me was $350 cheaper than going back with standard 3 tab shingles.
How many 50 yr old barns ya see with their original shingle roof vs tin roofs ?


Ethical behavior is doing the right thing when no one else is watching - even when doing the wrong thing is legal. Aldo Leopold .. (except when it comes to trailer tags)