I am building a new post frame barn/garage.  Part of the building will air conditioned.

My builder is offering a steel ceiling liner.  Steel, rather than drywall, seems to be the standard in the industry.  (A benefit is it can span 4 feet between trusses.)

My question concerns vapor transport.  During summer, a drywall ceiling with latex paint or a class II vapor retarder can dry to the interior.  A steel ceiling, however, cannot.

If I go with a steel ceiling, am I inviting condensation, wet insulation, and mold/rot in the attic when warm, moist air reaches the steel?  I would use either blown cellulose or Rockwool batts.  July often has multiple weeks of 72+F dew point (zone 5A).