I’m working on a project in Climate Zone 5. This is a sprinkler system addition to a 5B dormitory building. The existing condition is that there is a gypsum board layer attached to the bottom chord of the roof trusses, and there is a suspended acoustical ceiling a few inches below that. The owner wants to install a dry system in the attic which means removing the gypsum board lid, the suspended ceiling, and just replace with another suspended acoustical ceiling (not replacing the hard lid). In doing so, we are losing our air barrier. I’m looking for a way to satisfy the requirement for R-49 insulation, air barrier, and vapor barrier as indicated. I’m seeing conflicting information on whether a vapor barrier is required or desired in this situation. There are roof vents. I’m unsure at this time if they are powered, and I’m unsure if there are soffit vents. I’m trying to get this information. Any thoughts would be appreciated.