If I use a 11 1/2" I-joist can I span a 22' ceiling with 16" oc? It is for a room I am building in my barn. There won't we a lot of weight on the ceiling and I am a DIY that wants to make sure it won't fall down on me.

According to the Forest Products Supply Company website 11-7/8 inch TJI 560 I-Joists can span 22'-4" spaced 19.2 inches apart or 23'-8" spaced 16 inches apart with a 40 psf live load and 20 psf dead load. The 19.2 inch spacing comes out to 5 I-Joists per 8 feet versus 6 I-Joists per 8 feet with 16 inch spacing.

https://www.fp-supply.com/st-louis-t...-i-joists.html

As an alternative to I-Joists, you might want to look into a roof truss system designed to include storage. The roof framing and attic floor framing are all one assembled piece which would simplify construction greatly and be at a lower cost.

https://hw.menardc.com/main/store/20.../GABLEROOM.jpg