Sand or low density fiberglass for floating floors?¿

Hi, I'm building 7 rehearsal rooms, and 3 of the floors are builded with sand between joists. I'm thinking of change the material to fill the space between joists, but high density rockwool is so much expensive than sand. The only material that is not much expensive than sand is low density fiberglass. I need 110 mm thickness material, and I'm thinking of two plies of low density glassfiber 80 mm a bit compressed. What about this? will my floors be so boomy? --- Look at my brother cultivating potatoes :lol: :lol: --

STOP! If you do not design the floating floor(s) prperly you will make things much worse! Do a search here for flating floors and Paul Woodlock. He has the best info around here (as a regular reader and contributor) on floating floors. Andre

hi hugo, Andre hit's the nail. Paul is the man in this case (besides Eric) His studio build diary: http://forum.studiotips.com/viewtopic.p ... sc&start=0 and my own floor thread where Eric and Paul explain some things: http://forum.studiotips.com/viewtopic.php?t=1586 :D