What's my best choice?

I need make a wall more soundproof without increasing it's original depth more than inch or less . Need as much low frequency attenuation as possible. The outside is stucco. The inside is 2 layers drywall on studs. Do I.... 1) add resilent channel and add a layer of Quietrock or Supress. 2) demo all the drywall, add the channel, Quietrock, green glue, dry wall. Obviously all the demo is costly in time, labor but is there a signifigant difference soundwise. What would be the best solution without considering second walls, etc. Thanks.

woodlakesound wrote:

I need make a wall more soundproof without increasing it's original depth more than inch or less . Need as much low frequency attenuation as possible. The outside is stucco. The inside is 2 layers drywall on studs. Do I.... 1) add resilent channel and add a layer of Quietrock or Supress. 2) demo all the drywall, add the channel, Quietrock, green glue, dry wall. Obviously all the demo is costly in time, labor but is there a signifigant difference soundwise. What would be the best solution without considering second walls, etc. Thanks.

If you're looking for the greates Isolation the answer is neither of the above. Personally - I would remove the existing drywall carefully cutting exactly at the edges of the framing. I would then remove the left over strips of drywall from the wood. The I would install the drywall pieces between the studs - up tight against the exterior sheathing - and caulk the edges........ I would then install 4 layers of drywall on the inside face of the wall and use green glue between the layers. I would not bother with green glue against the exterior becasue your weak link is the studs themselves. Rod

I hate you :D So the Green Glue is the way to go? Do you have a personal experience with both Quietrock (not a fan of it, just for space saving) and Green Glue for comparison. I like your idea very much, it could be a great option if the payoff is greater low frequency attenuation thanks....

woodlakesound wrote:

I hate you :D So the Green Glue is the way to go? Do you have a personal experience with both Quietrock (not a fan of it, just for space saving) and Green Glue for comparison.

Look at it this way - at 50 bucks a sheet (the cheapest 4 x 8 x 1/2") you could buy 5 layers of drywall for each sheet of Quietrock l(Which would give you greater isolation value) - add to that the cost of RISC clips (at 4 bucks a pop) plus hat channel (at 4 or 5 bucks a pop depending on where you buy it), and suddenly you begin to see the cost savings going with drywall. It's mass that will make the big difference - and green glue with 2 layers of drywall is almost equal to 4 layers of drywall. Cost is just about the same (as 4 layers of drywall that is).

I like your idea very much, it could be a great option if the payoff is greater low frequency attenuation

The payoff will be MUCH greater low frequency attenuation. PLus saving some dollars in the process. Rod thanks....[/quote]

Ah yes, obviously a cost savings but that was not my main consideration. Space is. But as it turns out, I'm only adding two layers of drywall and green glue combo. How much does the glue add to depth? I might even go with two or three tubes per panel in this cove area next to the carport. That's a hell of a sandwich. Is it worth it? I have about 600 sq ft of wall space altogether. Thanks again....

woodlakesound wrote:

How much does the glue add to depth? I might even go with two or three tubes per panel

For all intent and purpose - it doesn't add anything to the depth.- the sheets still screw tight together. Why in the world would you want to add more glue than recomended by the namufacturer? That sort of logic is like saying - "they said to add one teaspoon of salt to the recipe, so 2 or 3 teaspoons should be even better." Believe me when I tell you this - if Audio Alloy knew that doubling or tripling the amount of glue used could increse your isolation value they would use that as a selling point. Seeing as they aren't - you won't - so don't. Rod

http://www.acousticalsolutions.com/prod ... n_glue.asp I'm gullible I guess. Is this BS? :oops:

Nope, it's genuine. Good stuff. Do searches here for "green glue" (be sure to enable the "search for all terms" option) and you'll see. Although you should buy it straight from the source: http://www.GreenGlueCompany.com It's good that your B.S. detector is working though. A lot of stuff out there is B.S. Now how about going to the "DON'T EVEN think ABOUT POSTING before you READ THIS..." thread and following all the guidelines? ;-) (Namely, adding a location to your profile, and getting friendly with that "search" feature.) --Keith :mrgreen:

Thakyou, I've done some reading here but I was led astray at the start of my project over a year ago. I had the funds to hire a designer that took a few liberties and made assumptions about the needs for outside sound control. We are presently in a minor battle as how to resolve a few problems. One is the room sound within where there is modal ringing in the 120hz area directly center of the octagon. It's obviously fixable, porting some of the panels to attic that is fundamentally sealed from the outside. Still a work in progress there. But the wall to the left (not straight on but lengthwise and almost hidden from camera view) needs the reworking, as well as the cove to the door. I have a frabric over 703 system that easily can be taken down and back up. Just tonight the designer and contractor involved want to use barifoil on top of the drywall to attenuate broadband as well as the low stuff, but it sounds rather dubious to me as to its effectiveness. Expensive...very..... but the fix and cost is mostly in their hands unless I want to just get my money back for the cost of that section alone and I'll just do it my way. So here at DIY-land I know most would scoff at the Barifoil (I never heard of it) and just drywall + green glue if no structural element could be introduced. But we have demo to consider and time..... so what do you all think a good solution might be?

Wow, that's a beautiful space. Sorry it's causing you trouble. So, the wall that has the problems -- would that be the one with the windows in it? (Are those windows?) Perhaps you could take a picture of just that wall, outside and inside, and post a diagram of its exact makeup (cross section view). I know you described it already, but a diagram might go further. As Rod indicated, your fix may be much more surgical, and it may be inpatient. (No pun intended, Rod! ;-)) --Keith :mrgreen:

rod gervais wrote:

woodlakesound wrote:

How much does the glue add to depth? I might even go with two or three tubes per panel

For all intent and purpose - it doesn't add anything to the depth.- the sheets still screw tight together. Why in the world would you want to add more glue than recomended by the namufacturer? That sort of logic is like saying - "they said to add one teaspoon of salt to the recipe, so 2 or 3 teaspoons should be even better." Believe me when I tell you this - if Audio Alloy knew that doubling or tripling the amount of glue used could increse your isolation value they would use that as a selling point. Seeing as they aren't - you won't - so don't. Rod

Form GG's website 17. How much do I need? Recommended application is 2 tubes of Green Glue per 4' x 8' area - 2 tubes per standard sheet of drywall. If you are not on a budget, utilizing 3 tubes per sheet will improve performance. Each case of Green covers about 192 square feet, or 128 square feet if used at the 3 tubes coverage rate. Do not use more than 3 tubes per 4' x 8' sheet as performance will actually decline above 3 tubes per sheet. You are just wasting your money! 18. I need to soundproof on a budget, how can I reduce the cost of a Green Glue room? Wonderfully, Green Glue performs at an only slightly lower level if you use it at 1.5 or even 1 tube per sheet instead of the recommended 2. about 70% of the raw damping performance is retained when using 1 tube per sheet, 3rd party tests coming soon. In fact, Green Glue can improve performance if used at even less than 1 tube per sheet.

I checked out Green Glue's website too, and it does seem like they're recommending 2 and even 3 tubes per 4'x8' panel for improved performance if it's within your budget. The Green Glue calculator suggests 12 tubes for six 4'x8' panels and calls this 100% coverage. 50% coverage is one tube per panel. Rod, am I missing something? It seems like you were saying to use only one tube per 4'x8' panel when woodlakesound said he might go with 2 or 3 tubes per panel (which Green Glue does seem to be recommending). So, why the one tube per 4'x8' panel? Not trying to be argumentative, just trying to understand. I want to use this stuff in the future myself.

Coyote wrote:

Rod, am I missing something? It seems like you were saying to use only one tube per 4'x8' panel when woodlakesound said he might go with 2 or 3 tubes per panel (which Green Glue does seem to be recommending). So, why the one tube per 4'x8' panel? Not trying to be argumentative, just trying to understand. I want to use this stuff in the future myself.

Coyote, I apparently missread the post - I thought he meant adding 2 or 3 tubes more than the manufacturer recommends - hence my statement that he should only use what the manufacturer says to use. Sorry for the confusion. Rod

sharward wrote:

Wow, that's a beautiful space. Sorry it's causing you trouble. So, the wall that has the problems -- would that be the one with the windows in it? (Are those windows?) Perhaps you could take a picture of just that wall, outside and inside, and post a diagram of its exact makeup (cross section view). I know you described it already, but a diagram might go further. As Rod indicated, your fix may be much more surgical, and it may be inpatient. (No pun intended, Rod! ;-)) --Keith :mrgreen:

Here is a CAD layer to help. I think you can plainly see where the trouble is. Take it from the door at hallway and counterclock till the drum room wall. Fortunatly I kept my old wall in the DR.... resilient channel, drywall, soundblock barrier, drywall. I need at least that STC for the rest. Again, they want to use Barifoil as a overlay on top of the 2 layers of drywall instead of all the demo agony involved in rebuilding the drywall layers. I'm pretty sure the drywall green glue combo built up over 4 layers is gonna kick some serious butt, however the option is still not being presented to allow that without serious negotiation as to who's gonna pay what % do to design neglect. My professed aim was to have the classical crowd enjoy a quiet space and specifically classical guitar (which is my instrument). So the 2 layers of drywall isn't feeling all that cocoon-ish to my senses. Fortunatley, it is a quiet neighborhood and the street is a good 70-80 yards away. But driveway traffic and the neighboors lawn mower, ect. Then the door from the carport (above the cove) is ridiculously loud when closing. Can't believe I let them bypass what could have been easy straightforward solutions. But this is where we are.... damn!!! So.... Barifoil, what is it? Does it work as an overlay? Keith I just checked your www. and very very interesting. I DL'd the little wall anatomy jpg. for further consideration. Add a little green glue to the equation and there you have it... Hitler's bunker. :lol: Ok... not so funny. Too much History Channel.

I'm glad you're benefitting from my thread. 8) I just hope you realize that my plan underwent many, many iterations, so it's quite possible that there's a newer illustration beyond what you grabbed. My planning and replanning took eight months. Also, be aware that the calculator on the Green Glue site figures full cases only, so with 100% coverage you'll probably have tubes left over. You'll also want to study this page to see why STC is bogus in the studio context. --Keith :mrgreen:

OITC....gotcha...thanks.

What's OITC? :?

hmm, "oh, in that case" ? (just quessing)

sharward wrote:

What's OITC? :?

From your link Keith.... "Are there better rating systems? Yes, the best standardized rating system in North America is called OITC, and is typically used for exterior wall elements. OITC features a modern calculation system and considers frequencies down to 80 Hz. In Europe at times full-range standards are applied. An assessment of existing standards is given in the appendices of this document. The Green Glue Company presents, in several of our technical documents, full frequency range calculations based on advanced techniques. We took a different path than some of our competitors in this market in that, instead of attaining high STC’s and marketing them, we have paid to have many walls (with many more to come) tested down to very low frequencies all in the same lab - to avoid the lab-to-lab problems that can cloud low frequency data. We hope our efforts serve you well. As the ASTM standard that shows us how to calculate STC teaches, in our technical documents we assess the performance of walls considering the entire relevant frequency range, and performance in individual bands."[/quote]

Ohhhh yeaaaaahh! :lol: Doh! :roll: Actually, I'm guessing that low end TL is your issue, and that's what you would need to address. In that case, widing the air gap and increasing the mass is your ticket to success. Green Glue will help too. --Keith :mrgreen:

As an update to any interested, I sent my order for Green Glue today for 9 cases. What was suggested by the company was.... to get the same depth value I need in order to reassemble my molding, fabric wall, door jams, ect. to the pre demo state was to use 3 layers ( 1/2....3/8.....3/8 ) GG in between . Also working drywall and caulking against the sheathing and using GG there as well. This product really sounds like a life saver for my situation, though I wish I could add much more mass, this will have to do. Comments? How's my plan. I'm laying the GG on max in the areas where low frequency attenation is more problematic. Think I'll search some of everyones experiences here with GG. Thanks for participating in my thread.

You'll definitely want to post a detailed drawing of the anatomy of the wall as it exists today and as you propose to make it. More photos of your exsiting situation would help a lot too. I suspect that you may not need that much Green Glue. 9 cases = 84 (EDIT: no -- 108!!) tubes = enough for 42 (EDIT: no -- 54!) 4x8 drywall panels at 100% coverage. I don't think you need to use all those different thicknesses of drywall. I would think two 5/8" would be fine and would be a lot less labor. I don't see why not extending the thickness of the wall into the room would be such a big deal. It seems you have the space to spare. Are you really only trying to avoid "trimming your trim"? --Keith :mrgreen:

9 cases = 84 tubes Is my math getting rusty, or are there 9-1/3 tubes of GG per case? :wink: I'd like to see present and proposed wall details too, preferably BEFORE the dirty deed... Steve

knightfly wrote:

9 cases = 84 tubes Is my math getting rusty, or are there 9-1/3 tubes of GG per case? :wink:

I'm such a dolt! 9 cases x 12 tubes per case = 108 tubes! I was thinking 7 x 12. Hey, it's late! :lol: --Keith :mrgreen:

http://search.earthlink.net/search?area ... m+Barifoil One of the shortest googles I've ever seen, short of nothing at all :? Don't think this is a good idea, considering that unless you put the lead side toward an existing mass you'd create another leaf in the wall - and if you DID put the lead toward the wall, you'd have a foam surface :roll: ... Steve