Warm / Cold Garage Roof

[mikkymo]

I'm building a garage which will have a PVC coated box-profile steel roof on top of wooden trusses. The ceiling of the garage will be insulated with 150mm mineral wool, then vapour barrier and 2 layers of 12.5mm plasterboard. The idea is to keep noise down as much as possible so I can tinker away inside and the kids can use it as a playroom. Internal stud walls are also going up for the same reason.

Does this setup leave me with a warm or a cold garage roof?

Do I need the non-drip fleece lining on the inside of the steel roof sheets?

TIA!
M

 

[noseall]

Do I need the non-drip fleece lining on the inside of the steel roof sheets?

No. What you need to do is re-think how you are covering your roof in view of the fact that this will not be a garage but a habitable play room.

The problem is condensation on very cold winter days. Unless you are using directly bonded insulated sheets and have a decent roof ventilation spec', then you will struggle.

Incidentally, your roof spec is a cold roof and needs venting as such.