I think the approach i'm going to take in ceiling
Think this is what your saying (from subfloor moving down to HT ceiling):
subfloor | safe&sound | air gap (?) | pink Insulation | clips & channel |
1/2" OSB | green glue | 5/8's wall board | plaster (?)
where i'm doing:
subfloor | safe&sound | air gap | safe&sound | 1lb MLV | clips & channel |
1/2" OSB | 1/8" FloorMuffler | 5/8's wall board | green glue |
5/8's wall board | plaster
Think the OSB question was about stiffness. 1/2" OSB has some flex and suspect it should work as one side of the green glue sandwich. In my case with 3 layers I'm not sure if it's reducing the effectiveness of the green glue. I'm hoping for some absorption in both the green glue and floor muffler but ...
It's an experiment which, If I get ambitious, I might try to measure.