Treating the Top-Side of the Ceiling

Hi, I have a one-room studio (former attached but since enclosed home garage) in the plans and I am limited by my floor to ceiling height to basically 2 5/8" sheetrock sheets with Green Glue on the inside room ceiling (this is due to acoustic design and desired space). The house is a 1 level on a common slab. The walls will be on seperate studs and there will be no 3 leafs. I do however have a large attic space common to the whole house. Can I use multiple layers on the top-side of the ceiling joists and just cover the area over my studio room; and expect good isolation? Would it be best to do some type of OSB/sheetrock sandwich in the attic with Green Glue involved? Possibly installing RC2 inside the attic and mass on top of it (albeit upside down from standard usage)? My attic joists run the length of the house and this room is on a hip side so I would need to isolate inbetween the joists going to the soffett vents and opposite side as well. Sorry it's hard to describe! thanks for any help! Tapp

I would have to advise against this - it's important that your roof be ventilated - othrwise you can get structural damage from moisture - which is why the vents are there in the first place. Rod

Thanks Rod! So, should I put nothing but insulation in the attic area? Could I do some decking up in the attic making sure that the soffit vents are open on the sides or am I just wasting money with this idea? I'm just hoping that 2- 5/8" layers with 2 tubes of green glue (per sheet) will give me enough isolation from the rest of the house. I'll lose my needed height if I go with the iso-clips and RC. Tapp