....I laid 1/2 plywood strips on the center of the joists(2" wide)
prepainted drywall went inbetween the plywood
I then screwed 2x3's in the opposite direction to the joists on 1' centers, and filled the gaps with 2x4x24 insulation, ripped in both thickness and width
then nailed down t&g.
I was initially thinking i'd screw the drywall back up to the 2x3's, but never had to, the drywall is still flat after 15yrs.
the joists were on centers that allowed me to use 24" wide strips of drywall(i.e. 26")
in wider joist spans, one might have to screw off the drywall.
