The ceiling joists in my garage are 2x8 spaced 24" o.c., and span 21'. The roof load appears to be carried by the walls, so the joists seem to only be in place to hold the drywall.
I'd like to use the space for light storage (holiday decorations, etc), but I'm not sure if the joists are up for the task. Obviously I'd want to add some decking; so items don't fall through the drywall, but that also adds to the weight the joists will have to carry.
Will I be able to do what I want, or will I have to upgrade the joists?
Since it's a garage (where cars have to park), I can't add mid span support without a huge undertaking.