Condo soundproofing ...
 

I have a two story condo that shares a common wall with a single story (vaulted ceiling) unit. I am going to be attempting some soundproofing on the common wall which is a staggered double stud wall. My plan at this time for the wall is to use Green Glue and 5/8" drywall.

My question is regarding the floor joist cavity area that abuts the common wall. The joist run perpendicular or 90 degrees to the common wall. I would like some opinions on what might be a good way to reduce the noise transmission in the area between the 12"-joists where the floor meets the wall, not sure of the spacing yet.

If I have to I can access that area buy cutting an opening in the drywall ceiling from below. I was think about caulking and batt insulation a foot or two of that area next to the common wall but after reading the "Sound Proofing with blown in insulation" thread it sounds like that might not be too effective.

Thank ...

I think you answered your own question on how to do this, the good thing about Batt is you can cut it to any shape u want.

What type of insulation material would be most effective for that application?

You dont want blown in insulation that's if your doing a hole floor or entire house
The batt is what u want put the spray foam in a can in any cracks you see.

Fiberglass?

With or without foil or paper backing?

I guess I'll seal then a layer of fiberglass insulation and top that with cotton batt or Roxul maybe ...

Thanks ...

Attachment 3129

http://www.soundproofcow.com/soundproofing-insulation/soundproof-insulation-batt.html

This is what u want. U can use pink for small cracks if you want.

Thanks but way over budget, the green glue and drywall for one small room are less than one 5"x8' batt.

Oh ok sorry about that.

If you have staggared 2x4 studs in a 2x6 wall you will have limited success because the the 2x6 top and bottom plates are common and they transfer sound to your joists.