Double wall insulation question

I've been searching and can't seem to find an answer to this specific question. I'm building a double stud 2x4 wall with 2 separate plates and a one inch gap. Each wall will receive 2 layers of 5/8 gypsum. -I see in posts to put "insulation" in between the studs. Does this mean the 703 rigid or the fluffy pink or yellow home insulation you buy at Home Depot? -If it is the standard insulation, can I staple it up with the paper side facing the drywall? What "R" rating should I get? -Do to certain structural issues I can not decouple the ceiling from the walls. So my next question, will Green Glue increase isolation significantly if used? If Green Glue will be worth using where should the priority be since it is so expensive? -Rendering below no longer has dual sliding doors. Now has standard 36" solid core doors. Rod Gervai's book has great details of Door designs. Great Reference.

see in posts to put "insulation" in between the studs. Does this mean the 703 rigid or the fluffy pink or yellow home insulation you buy at Home Depot?

It means unfaced fluffy pink or yellow stuff, if you have the budget you could use some rockwoll too. Bats in the cavities are mainly use to damp panel resonances.

-If it is the standard insulation, can I staple it up with the paper side facing the drywall? What "R" rating should I get?

No paper, if you can't find any insulation without paper then yes , paper toward drywall. R13 or at least 3" thick.

--Do to certain structural issues I can not decouple the ceiling from the walls.

You're seriously compromising your double partiton wall then, remember that your construction will only be as good as your weakest point. you won't get better result at putting 5 layers of drywall with green glue on your walls if you have serious flanking or structural path.

--So my next question, will Green Glue increase isolation significantly if used?

In short yes. see previous questions. I'd suggest a re-read of page 62 of Rod's book from paragraph 3, since you have the book i am sure you can find a way to decouple your walls from your ceiling. have faith :wink:

Well said, Eric. 8) I concur, as I'm sure others do as well.

What about using resilient channel to improve iso? Say on the live room ceiling and common wall with control room?

Egg Can you give more info for your project, like Available height, where do you plan to build (basement, 10th floor....), isolation needs. You may review the "Don't post before you read this" section to be more specific and precise in your description and needs. It is hard for anyone on this forum to give a sensible answer when we don't have all the variable in play. That being said. Resilient channels for your ceiling is an exellent idea. RSIC-1 Clip with hat channel would be even better. Buildind a new ceiling on top of your walls would be the best, but i suppose you do't have the height..right ? Keep in mind that your walls frame must not touch in any way the building structure (exept the concrete floor).Do not use resilient channels on a double partition walls it is just useless. These things are use for single partition walls/ceilings.

I'd also be interested to hear any practical suggestions regarding the ceiling situation as it's one I'll face myself before too long. In my case it's due to structural joists about 2.8m above the floor and too close together to contain the width of the rooms. I'm only building rehearsal rooms however, not a studio.

ADDITIONAL INFO: -Located on a concrete slab with no one above. -Ceiling height is 10.5 to 8ft -I'm looking to achieve the best iso possible with RC and drywall. -In the live room I have all of the walls and ceiling decoupled from the structure except for the west exterior wall. The framing on this wall is set in from the exterior mason wall 2 inches, but the top plate is LOAD bearing. I cannot decouple it and I can not build an additional wall next to it because of space. -In the control room all of the walls and ceiling are decoupled except the except for the west wall of the CR. This wall is a center span load wall. -The joists run from east to west. -Pictures to come. QUESTION: What STC rating can I hope for with dual 5/8? Even if I have a double wall shouldn't I use resilient channel in the live room on every wall and the ceiling? I have one wall that is coupled in each room and will have some flanking going on. Should I go with resilient in the CR as well?

Revised inquiry with additional info. Pix to come as soon as I can get them.

With separate wall frames, you have no need to waste money, time, or space on resilient channel. You already achieve decoupling by having separate frames. --Keith :mrgreen:

Thank you for the quick reply. But even if i have only one wall in each room carrying load (hence flanking) shouldn't resilient channel be used somewhere in this design?

I was going on what you wrote:

egg wrote:

What STC rating can I hope for with dual 5/8? Even if I have a double wall shouldn't I use resilient channel in the live room on every wall and the ceiling? I have one wall that is coupled in each room and will have some flanking going on

I guess we need to get on the same page as far was terminology goes. "Double wall" usually means two decoupled frames, each with its own "leaf." The leaf is often stucco, plywood, OSB, MDF, or any combination of these or any other dense, air-tight products. You can (and usually must) have multiple "layers" of products within a leaf. When you wrote "double wall," I assumed you meant two frames. Now I'm thinking you meant two LAYERS of drywall. Study some more here about various wall constructions, seeing how different formulas result in different performances. Follow the link to the IRC report in the "Reference Area" sticky thread. Understand too that STC is a practically worthless measurement in a studio context. --Keith :mrgreen: