I've removed the 12 x 12 tiles and the old insulation in the garage ceiling. The 1 x 1s that held the tiles are still there. I can get the bat insulation through them and they hole it in place. My question is, Should I removed the 1 x 1 so that the insulation is tight with the drywall ceiling? Also, has anyone here used Guardian Insulation? It's half the cost of Owens Corning.