Shouldn’t sweat so long as you have 6 mil vapour barrier then insulation. If ceilings were to ‘sweat’ You’d have a lot of moody drywall out there wouldn’t you. Vapour barrier and insulation are the key.

 

Spray foam insulation is popular nowadays too and also acts as a vapour barrier. In my parts it’s a bit more spendy though. Check with your local building supply companies for direction on this. Also exteriors specific supply companies will have the latest on all the roofing technologies available to you.

 

Not a cold environment.. as I have R52 in the ceiling, but you'll love the light reflection and clean look of just using galvanized roofing for a ceiling..

 

We have steel ceiling and tube heat, Spray foam insulation, dry ceiling all winter here in Iowa.

 

I live in an actually cold place. Lotsa metal ceilings and walls in garages and wash bays, etc.
Vapour barrier is key. In Canada by code it is, I think, 6 mil plastic which is very thick, not like Saran Wrap. Fibreglass batts under that.
At least here the facing on insulation is no longer considered vapour barrier.

 

I have a small unfinished room in my shop. metal roof, un-insulated, always dry........ my floor however, in the insulated area; sweats horribly on humid, rainy days when the temperature is right..... go figure

 

I have a metal ceiling in all my exterior ceilings with blown in cellulose insulation and no vapor barrier. Last I checked steel holds water quite well. I keep the shop at 60* minimum most of the time. Mid Michigan.
Mike