I'm working on insulating and closing in my garage to make a workshop. Currently its just the exterior polyisocyanurate sheathing and studs. Its all open to the rafters, which are uninsulated. There is a top plate at 8' where the pitch starts. On top of the top plate there are several 2x6 tie joists that span from the rear of the garage to the front (about 22'). They are 4ft on center.
I want to put a ceiling up (was thinking 5/8 OSB) and insulate above with cellulose or fiberglass. I'm just worried about putting too much weight on those tie joists. Would it be a good idea to add some in between or would it be okay to just add blocking in between? There wouldn't be much weight up there besides the OSB and insulation.
Any help is certainly appreciated.