Sorry for the delayed reply - busy month
Thanks, Wuzzat, for all the info!
After thinking about this for the past month, I would really like to spearhead adding joists...
As I said, I do have construction experience; however, I have only installed floor joist on new builds / additions.
I said in a previous post that I would LIKE to add the joist without ripping up the subfloor (and damaging the existing flanges). I would like to position each joist laying on its side where it's going to go (in the centers - not sister joist), add glue on the flange, then beat the joist upright into place, then someone on top will screw down via chalk lines.
This may be a long shot, but is there anyone out there that has done this? CAN it be done?
Furthermore, Would this help to make the floor feel more solid? Would it be worth the money / effort? The floor is not 'bouncy' per se - but it would be nice to stiffen the floor (as well as close the 24" gap before installing the new tile / hardwoods)