On Friday, 8 July 2016 16:37:18 UTC+1, Mr Pounder Esquire wrote:

Many years ago when I lived in Australia some houses had "tin" roofs.
Apparently when it rained the noise was awful.

Made up for, no doubt, by the fact it was raining.

The tin has several inches of insulation under it. The major problem is preserving the weather seal at joints. Tin flexes in violent winds and expands and contracts a lot more than stone or clay. Large sheets being both a blessing and a downfall. I imagine going around the finished product with a soldering iron might be the only way to cure that.