metal roofing question

I had a Gerard roof put on (paid for by insurance after a big hail storm took out my heavy shake). They put it over the shake but put down 1x4 and

1x4 vertical on the roof and then 2x2 horizontal and then the panels attached to the 2x2.

Put the metal on over the wood strips. Screw the wood down too, hit the trusses. Then you will have some wind protection.

Just a guess, but the manufacturers probably have a better idea of what works for their product than any of us here. I'd follow their recommendations. What may be good for one brand, may not be for another.

Speaking from experience. I had a metal roof put over my uninsulated roof (floor insulated), directly over the shingles. Had the same two choices you have - direct or raised on studs. Wish I had spent the little extra. I now have mold problems on the inside wood of the roof due to lack of circulation and the heat/cold issues with a metal roof (condesation). Since the attic is unoccupied, I just leave a window open in the winter for air circulation which has helped lessen the mold. However, I DO NOT regret a metal roof and still love it. No more ice dams, roof raking or weight from snow buildup. And it's not noisy when it rains, either. Sue Northern Wisconsin Envision Whirled Peas

Be sure you use screws, nails usually do not hold well enough.

How do you avoid noise? I was inside a house with fibreglass panels when it rained, it was like living in a snare drum.

it rained, it was like living in a snare drum.

Soft water? I don't know, perhaps the additional layers of old shingles. Now, the metal roof on the barn is a whole other story. A light drizzle sounds like a downpour. Sue Northern Wisconsin Envision Whirled Peas