I have installed and removed a number of metal roofs.
No longer a fan unless its standing seam.
Even then, personally I would not have another on my own home.
The typical 3 foot wide "AG" panel with a thousand holes that you hope are sealed with a neoprene washer are good for dog houses and pole barns.
In cold parts of the state, it takes several things for a metal roof to shed, above 32 temps and damn steep helps, however even a 12/12 pitch will not shed reliably unless it accumulates or warms up.
In most places of Alaska a metal roof and siding is the strongest and most economical way to go. A shingle roof would blow away the 1st fall in Bristol Bay,,I've seen it !! The gusset type style of pro-panel (the standard) is enormous and I havn't found properly torqued screws not to be a problem. I peeling off the cedar clapboard on our 20X24 and sheeting it this summer just for wind shielding alone.
Tend to disagree in regards to most part of the states but do agree in areas of high winds, low pitch roofs and minimal overhang's in those areas will withstand wind better.
Typical propanel screws are # 9 0r #10 X 1", in areas with sun and Bristol Bay may not be one of those, the small screws tend to loosen from expansion & contraction of the sheets, unless the lengths are kept short, especially if darker colors.
Once the screw is worked loose, the washer leaks, soon to be replaced with a #12 screw and finally a #14 and when that strips...... its caulking....
What a great roof, a sheet of 30 gauge metal with a million holes....... and relying on washers, great for dog houses and pole barns..... if you need metal go with a standing seam or klip rib system if you want something to last.
FYI, I have seen plenty of sheets of tin blown off of roofs or folded over in the villages.
