New Roof

[Devonian]

my uncle had a chalet with a metal roof, it was very noisy in the rain, I wonder if yours will be the same??

Not sure what LS has, but the noise problem is usually more of a problem on the single skin steel roofs, these days unless you are talking about an agricultural building, composite panels are generally used which consists of 2 layers of steel with a PU foam insulation sandwiched between them, this deadens noise, improves insulation and helps reduce condensation which can be a big issue for metal roofs - hence the tyvek which also acts as vapour layer to protect against condensation.