Spanning a ceiling
Make sure you check the requirement for the flooring you are putting above the room also (if there is a room above it). Some hardwood, and possibly other flooring, manufacturers require certain spacing that may exceed the requirements fo the joist/LVL manufacturer. I've had one where the joist guy said 24" o.c. and if I remember right the hardwoods needed around 19" o.c. Check with the joist guy first and then look at the flooring to see if you need to go beyond what the joist guy says.