I'm adding ceiling joists in my garage. It's a 19' span between walls, and I'm using structural or #1 lumber. Should I use 2x8x22 OR 2X10X22 spaced 12" on center? I'll be adding 1/2" or 5/8" drywall.
You added below the top of the wall in the comments. So I would lag a rim joist to the studs and use joist hangers.
Span will look like this:
2x10 @ 12oc for #2
2x8 @ 12oc or 2x10 @ 16oc for #1
2x8 @ 16oc for select