Leaf Issues

Greetings forum participants, I have a couple, among many, of issues that I'm currently dealing with in the build-out of a studio. I must preface these issues with the fact that when I started this project it had a much smaller scope and budget. I also had not properly educated myself to the techniques incorporated in building such a project. I have recently bought and read Newel and Gervais and I'm preparing to build the third, largest, room. This will be used as a tracking room. I'm also looking to make up, in part, within reason and budget, for the mistakes that i have made...That being said, here are the two main issues, with sub-issues/thoughts (neurosis) :shock: : 1. I have a 30' wall that i share with a neighbor. Isolation is key here. It is a 24" OC metal studded with one layer of drywall on each face, filled with R11 or lighter between the studs. -I've been told to open the face, facing my room, pull the insulation, and add two layers of 5/8" drywall with green glue and backer rod around the edges. I assume that I could not add more mass to this in fear of compromising the metal frame/fastener system. Then add mineral wool as a final layer to create the first leaf. The second wall of the double studded wall system would be spaced 2" from the aforementioned, existing, now embellished wall system, rest atop a floating floor system, and have 3" Roxul between 24" OC metal studs (maybe wood to bear the ceiling load) with Quietrock-GreenGlue-Quietrock inner leaf. -I've also been told the above solution is not practical and that i should add 1/8" MLV -Green Glue-5/8" drywall to create the first wall. I fear that this will create a three-leaf system if I create the double studded system. If the double studded system is not incorporated, I fear that the wall will not provide enough isolation. Ideas? 2. I ignorantly built a double studded wall system inside a room, potentially creating a four-leaf wall system. This room functions as an iso/drum room. The next room I built a single studded wall assembly (wood frame, 24" OC, 3" Roxul) 2" from the existing wall system which is single, metal-studded 24" OC with single layer drywall on each face, creating a triple-leaf wall system. I feel like an ASS!!! I want to raze the rooms and start over, but time and budget won't allow that. -Should I open up the interior faces and go in and attempt to cut the inner leaves out. Replacing the insulation and then facing it with QRock-GreenGlue-QRock? -Or, Can I get away with beefing up the interior leaves with the Queitrock-GreenGlue-Quietrock. If I have Wooden studs, how many layers of this Mass-RC-Mass system can i get away with (structurally) if I use 527 Quietrock-GeenGlue-527 Quietrock? What if they are metal 20-25 gauge (i know, two different things) studs? What would you do? Thank you for your time and thoughts. I would really appreciate your input. peace

Hi Karuna, and welcome. You should check out the stickies, and especially this post (click here) for information on posting here.

-I've been told to open the face, facing my room, pull the insulation, and add two layers of 5/8" drywall with green glue and backer rod around the edges. I assume that I could not add more mass to this in fear of compromising the metal frame/fastener system. Then add mineral wool as a final layer to create the first leaf.

So far, so good! Yup, that will work for your first leaf.

The second wall of the double studded wall system would be spaced 2" from the aforementioned, existing, now embellished wall system, rest atop a floating floor system,

Whoa!!! Floating floor???? Are you SURE you want do to that? Do you understand what is involved in doing that? Have you done the math? Did you read the sticky about floating floors? Hint: It is really, really hard to float a floor correctly, and really, really easy to TRY to float it but get it WRONG, which means that you made things worse than if you would have not even tried... FLOATING FLOORS: viewtopic.php?f=2&t=8173 Apart from that, your inner leaf construction plan sounds fine: a separate second frame with a large air gap (larger is better: if you can afford more than 2 inches, then do it), fill the entire air gap with wool (either mineral wool or fiberglass), and a few layers of drywall with GG.

... and have 3" Roxul between 24" OC metal studs (maybe wood to bear the ceiling load) with Quietrock-GreenGlue-Quietrock inner leaf....

Yup! That will work.

-I've also been told the above solution is not practical and that i should add 1/8" MLV -Green Glue-5/8" drywall to create the first wall. I fear that this will create a three-leaf system if I create the double studded system. If the double studded system is not incorporated, I fear that the wall will not provide enough isolation.

Exactly. You got it right: That would be a Bad Idea. You need to de-couple., and you need only two leaves, not one, not three.

I ignorantly built a double studded wall system inside a room, potentially creating a four-leaf wall system. This room functions as an iso/drum room.

Ouch! Four leaves on a drum booth is not good news. but you don't need me to tell you that! :)

The next room I built a single studded wall assembly (wood frame, 24" OC, 3" Roxul) 2" from the existing wall system which is single, metal-studded 24" OC with single layer drywall on each face, creating a triple-leaf wall system. I feel like an ASS!!!

The good news is that you realize what you did wrong, and aren't afraid to admit it! To me, that sounds like "Smart". It would be "ass" if you tried to do what a few posters here have done: pretend it is OK, and that the laws of physics can be persuaded to ignore their particular studios.... But I'd say that since you are here, admitting your mistake and asking for advise on how to fix, that definitely means you are smart, not an ass! (not even a smart ass... :) )

-Should I open up the interior faces and go in and attempt to cut the inner leaves out. Replacing the insulation and then facing it with QRock-GreenGlue-QRock?

That sounds like the best plan to me. I'm not sure that I understand exactly what you mean, and a SkethUp model or photos of the actual structure would be good. But the idea is to get the "extra" leaves off, and leave only two on each wall / ceiling. Don't forget that you can actually take off just the leaves facing into the rooms, and leave the leaves that face each other (inside the wall) in place! That would give you what is called "inside-out" construction, where you end up with studs facing the room and drywall on the other side of those studs. It's actually a good thing, since you can use the space between the studs for your acoustic treatment... So all is not lost: Your solution might be as simple as just taking off the drywall from the studs in the room. You could even use that drywall to beef up the leaf on the other side of the studs, if you want to. But post a diagram, photos, or best of all a SketchUp model of your walls, so that we can understand them better, then offer suggestions. - Stuart -

Thank you so much for your input Stuart!! I have spent the hours since posting, searching the related posts, as well as links off of those. I'm sorry for the hasty posting, I figured I would put it out there. I'm new to the forum and I have realized, after researching the forum's posts, that many, if not all, of my questions have already been answered. Again, thank your for your input and your patience. I will post the pdf of the CAD drawing as well as try to convert it to a Sketchup rendering. On a side note, after reading several posts I get the vibe that Quietrock is a waste of money. Do you think that 5/8" gypsum-Green Glue-5/8" gypsum is comparable? Or even 5/8" gypsum-Green Glue-5/8" gypsum-Green Glue-5/8" gypsum is a better solution than the Quietrock-Green Glue-Quietrock assembly descried before? I also take into account the additional time it would take to add the extra course of drywall as an expense. Can you recommend a good acoustic caulking? I will be going through many cases of it... Anyway I must go to sleep it's 4am and I'm at it again in 5 hours. I'll post the images asap. Thank you so much for your time and consideration Stuart. I will also check out the link regarding floating floors. peace