I have a couple of veterinary college laboratory classrooms in a building with a metal deck roof and metal bar joists. The room has a (now) partial suspended ceiling structure. There is automatic sprinkler protection provided both below the suspended ceiling (concealed heads) and above (upright heads). In one of the rooms, old-style lighting fixtures which were suspended from the bar joist system were removed, leaving "troughs" of open suspended ceiling areas with no ceiling tiles in place. In light of the sprinkler protection being provided both above and below the suspended ceiling, I'm trying to determine whether or not the suspended ceiling assembly needs to be made continuous, or if the above-ceiling sprinkler system renders this unnecessary. Thanks for any help.
DC Clint Johnson (Ret)