Looking for some insight regarding my garage build...

How thick should my walls be, should I float my floors (and if so, how), why is two leaf mass-air-mass design important, etc.

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The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

Is there any question that you guy's can't answer!? Hahaha, it is much appreciated.
Quote:
when beefing up my outer leaf for mass, would it be ideal to green glue each layer of drywall (if that's the material I choose to use), or does it make little difference?

You can look up the technical documents on Green Glue's website. You'll learn that the stuff is pretty magical. It offers great results without eating up space. It's really easy to install, much easier than adding more layers of heavy material. Basically, it's highly recommended.
Gotcha.
...when applying Green Glue, would it be ideal to trowel it onto the walls, or is that unnecessary?...I've seen it applied in a random zigzag motion, on pieces of drywall that were laid face down, but I'd rather hear how you'd do it, in the real world.
Quote:
I have access to a bunch of free ply/osb sheets, and was curious if wood offers the same quality of "beef" that drywall does, in this application, between studs on the interior of the building? That would be nice if it did.

Awesome. Use them. Wood does offer the same "beef" that drywall does, just differently. By differently, I mean that different materials have different surface densities. The reason drywall is often used is because it has the best cost to mass ratio. The only downside to you using something like plywood over drywall is that in order to obtain the same mass, you will have to use thicker/more layers of plywood. Thicker beef up material = smaller gap between your masses of your MSM system (unless you move your inner leaf further from your outer leaf which would also result in a smaller room). Heck, if we all could afford it, I'm sure we'd use materials like lead for our walls.
Well, wood and drywall are out the window, I'M GOING 4" OF STRAIGHT LEAD!!! :D I'm also taking donations! Hahaha...
All sarcasm aside, I'm into the idea of saving every inch that I can, and I would also prefer to work with drywall over sheets of ply, so I'll likely just go the 5/8" gypsum route.
Your cost to mass statement was very insightful, way to nail that down for me, Greg. :thu:

Would you recommend that I apply 5/8" drywall between the ceiling joists also (control room floor), to acheive more mass there also? Any other advice about that situation?
Quote:
I have gathered that cleats and side nailing are the idea here?...I'd love to understand that method clearly, if you wouldn't mind elaborating a bit.

I think you're completely understanding the procedure. Put up your beef up material (with GG between if you choose to do so) and press it up as tightly as you can. Install the cleats to hold the material in place. Obviously, seal around each layer with GG Sealant. That's it. It's a pain in the ass job, but obviously worth it.
Ok, great, that is encouraging to hear...I found a couple threads that mention the cleats, but have yet to actually see a picture of them in use, for reference. Do you have an image available, or can you point me in the right direction, so I can better visualize my approach?
Quote:
The reason drywall is often used is because it has the best cost to mass ratio. The only downside to you using something like plywood over drywall is that in order to obtain the same mass, you will have to use thicker/more layers of plywood.
Right! The density of drywall is around 680 kg/m3, while the density of plywood is only around 560 kg/m3. So you would need plywood that is 22% thicker to get the same mass. MDF is actually better than drywall: around 750 kg/m3. But it's also quite a bit more expensive. OSB is similar to plywood but a bit better: around 600 kg/m3. So you need OSB that is around 15% thicker to get the same mass as drywall.

Quote:
Heck, if we all could afford it, I'm sure we'd use materials like lead for our walls.
For sure! Lead sheeting is around 12,500 kg/m3! Yep, you read that right: About EIGHTEEN TIMES the density of drywall. So instead of two layers of 5/8" drywall, you could have a sheet of lead foil just 1/16" thick, and still have the same total mass. Lead is also "limp mass", which makes it even better for isolation.... on the other hand, it ain0t cheap, and is difficult to work with. However, there are some rather specialized products out there, that consist of thin lead sheeting embedded in drywall. Used for shielding places where radiation is a problem, such as hospital X-ray rooms, MRI and NRM rooms, science labs where radiation is an issue, etc. You can buy that stuff for your studio if you want: Huge amount of mass in a thin panel. But huge price tags, too!
...know of any hospitals closing down around Chicago? Haha..
The above numbers really give a lot of perspective, I wouldn't have guessed that plywood was so inferior to drywall, regarding mass. Interesting.
The normal recommendation is plain old 5/8" (16mm) fire-rated drywall, because as Greg mentioned, its the best compromise on price: reasonably high mass, lowest price per kg (or pound) of mass. It's also easy to work with. But there are alternatives, if you have lots of money and a need to save space. Even steel plate is good, at around 7,800 kg/m2 (11 times density of drywall. So is aluminium plate: 2,800 kg/m3 (4 times density of drywall). It's all about cost/benefit.

Quote:
Obviously, seal around each layer with GG Sealant.
Sealing is critically important, yes, but I'm not to keen on GG sealant. The actual GG compound is the best stuff out there, bar none, but their sealant isn't so good: it tends to shrink a bit as it dries, so it can crack if you apply it thick. And if you apply if thin, you need two or more layers... There are better sealants out there. So, to be clear: Green Glue compound between layers of sheeting: YES! Absolutely. Green Glue sealant: Not so much. Use alternatives.
Again, 5/8" will likely be my choice,...I'm glad to be armed with all this newfound knowledge!

Is steel plate used in this application commonly?...I never even thought of that. Probably good to block RF interference too, wouldn't you think?...not that I have that problem, just curious.

...and the actual, brand name GreenGlue compound is the best, you say, Stuart?...any recommendations for a source of said compound, besides online, or is that my best bet?...I'll be sure to look up the other's that were posted too, I'm sure there's a dealer with one of your recommendations around here somewhere, as I'd rather buy buckets locally, when I need them, though whatever dealer offers the best product at the cheapest cost would surely be preferable.

Thanks again fellas, I hope that you're getting paid psychologist rates, because you've already talked me off the ledge! :mrgreen:
-If you're in control, you're not going fast enough.-
Soundman2020
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Re: Looking for some insight regarding my garage build...

Post by Soundman2020 »

...when applying Green Glue, would it be ideal to trowel it onto the walls, or is that unnecessary?...I've seen it applied in a random zigzag motion, on pieces of drywall that were laid face down, but I'd rather hear how you'd do it, in the real world.
Follow the manufacturer's instructions ONLY! Use it exactly the way they say to use it, which is to squirt it on form the applicator tube in a random pattern, leaving just s small margin around the edges so you can hold the panel as you put it up, without sticking your fingers in the goo.
Is steel plate used in this application commonly?..
I've never heard of anyone doing that, but in theory it would work rather well. I'm just not sure how you would support such a structure...
Probably good to block RF interference too, wouldn't you think?...
Yep! I would think so. A totally isolated, totally shielded room... sounds like something the CIA might do...
...and the actual, brand name GreenGlue compound is the best, you say, Stuart?...any recommendations for a source of said compound, besides online, or is that my best bet?...
To be honest, Green Glue is the only game in town! There's a couple of other VEP-CLD manufactures out there, but their products just don't measure up very well, against Green Glue. It's expensive, but it's the best.

- Stuart -
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Re: Looking for some insight regarding my garage build...

Post by Gregwor »

Not sure if you can get it in your area, but I've had pretty good results with Sikaflex f11C. It's a multi-purpose sealant and adhesive, basically meant as bathroom/kitchen caulk, but it sticks like crazy to most surfaces, and is very flexible when cured (Shore A 45).
On Amazon.ca there was one case left, but after shipping, it works out to almost $20 a tube which is way too expensive.

I looked up the data sheet for the PL Acousti-Seal and it has a Shore 00 rating of 30-40 which is super super soft. I guess I'll just use it from now on. Man I don't look forward to working with that black goo :-(

Greg
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Soundman2020
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Re: Looking for some insight regarding my garage build...

Post by Soundman2020 »

it works out to almost $20 a tube which is way too expensive.
:shock: Wow! They saw you coming! That's steep. Here for a single tube bought at Home Depot, it costs me less than US$ 9 per tube. No idea why it's so expensive where you are.
Man I don't look forward to working with that black goo
Pretty much any good quality caulk will work just fine. It's not necessary to go with special acoustic caulk, or anything that's hard to work with. Take a look around your local Home Depot or Lowes, and see what they have. Get a couple of tubes to try, and go with the one that gets you best results.

- Stuart -
The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

So here is my first attempt using Sketchup.
Garage Studio_2D.jpg
This is the basic layout that I currently have in mind, though a few changes will likely occur, such as removing the rear exterior door..

..also, I may add a booth outside the live room entrance, on the inside of the stairs, for two rooms of isolation, but am still unsure.
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The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

...also, I am about to order a five gallon bucket of the GreenGlue compound (I think I have access to a fillable caulking applicator), a bunch of 5/8" drywall, and will be cutting wood strips (cleats?) for securing my newly "beefed up" exterior leaves, that will be two layers of drywall at least...which leads me to a question...

If I want to install two sheets of 5/8" drywall between each joist/rafter, will I only use one set of cleats to secure them both?

Does anyone have a picture of the cleats in action?...again, I think I get it, but would enjoy some assurance, through a visual at the very least.

I have yet to measure SPL's to attain my isolation needs, but I know that I need 110dB at least...I lack an understanding of weighting, so please bear with me.
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Soundman2020
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Re: Looking for some insight regarding my garage build...

Post by Soundman2020 »

to attain my isolation needs, but I know that I need 110dB at least...
Ummmm.... Galaxy Studios in Belgium is arguably the best isolated studio on the planet. They hired the best acousticians in the world when they did that, and spent millions of dollars to get it right. Their isolation is about 100 db. You want to go ten times better? :shock: I think you probably wrote the wrong number there: Perhaps that is your PEAK sound level that you expect to have in your room? It certainly can't be the amount of isolation you need... :)
If I want to install two sheets of 5/8" drywall between each joist/rafter, will I only use one set of cleats to secure them both?
That's fine, yes. You might find it easier to put up the first layer with temporary cleats, then put up the second layer later (after the caulk has cured) with the final cleats.

- Stuart -
The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

Soundman2020 wrote:
to attain my isolation needs, but I know that I need 110dB at least...
Ummmm.... Galaxy Studios in Belgium is arguably the best isolated studio on the planet. They hired the best acousticians in the world when they did that, and spent millions of dollars to get it right. Their isolation is about 100 db. You want to go ten times better? :shock: I think you probably wrote the wrong number there: Perhaps that is your PEAK sound level that you expect to have in your room? It certainly can't be the amount of isolation you need... :)
If I want to install two sheets of 5/8" drywall between each joist/rafter, will I only use one set of cleats to secure them both?
That's fine, yes. You might find it easier to put up the first layer with temporary cleats, then put up the second layer later (after the caulk has cured) with the final cleats.

- Stuart -
Hahaha, yes Stuart, I'm an idiot, I meant that as a peak level, which still doesn't answer much, I know..

..but ok, temporary cleating, I'm picking up what you're putting down. Thanks!
-If you're in control, you're not going fast enough.-
The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

Happy weekend!

So i just scored a bucket of Green Glue and an applicator for $25 on craigslist. Bonus!

I'm going to begin the process of "beefing up" my exterior leaf today, finally, and I have a couple basic questions...

---- When I apply the GreenGlue to the exterior plywood sheathing (from the interior of course), and then install the first layer of 5/8" drywall to it (w/wood cleats), does it make any difference which direction I install it, face or rear? ...I can't imagine that it would matter. :roll:

---- Also, since the compound never really hardens, how long would you recommend I let it 'cure' before removing those retaining cleats, applying the second layer of GreenGlue & 5/8" drywall, and reinstalling those same cleats outside the second layer, permanently?

Thanks in advance. Cheers!
-If you're in control, you're not going fast enough.-
Soundman2020
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Re: Looking for some insight regarding my garage build...

Post by Soundman2020 »

---- When I apply the GreenGlue to the exterior plywood sheathing (from the interior of course), and then install the first layer of 5/8" drywall to it (w/wood cleats), does it make any difference which direction I install it, face or rear? ...I can't imagine that it would matter.
No difference at all, acoustically, but it's a lot easier to lay the drywall on the floor, squirt the GG on it, then lift it into place! If you try to get the GG on something above your head, you'll end up looking like a monster from a horror movie, with green goop dripping all over you... :)
---- Also, since the compound never really hardens, how long would you recommend I let it 'cure' before removing those retaining cleats, applying the second layer of GreenGlue & 5/8" drywall, and reinstalling those same cleats outside the second layer, permanently?
A day or two is plenty. It's not going to move much once you get it up there, plus you'll have the caulk already in place, all around the edges, so it will be pretty much sealed in place by air pressure: if no air can get in behind it, then there's a partial "vacuum" behind it if it tries to fall. You could likely do it as soon as the caulk is dry.

- Stuart -
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

Gotcha, that all makes perfect sense, Stuart, thanks.

...and now, may the hoarding of caulk and Green Glue commence!
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Re: Looking for some insight regarding my garage build...

Post by Gregwor »

I looked up the data sheet for the PL Acousti-Seal and it has a Shore 00 rating of 30-40 which is super super soft. I guess I'll just use it from now on. Man I don't look forward to working with that black goo :-(
After personally having a nightmare with this stuff 14 years ago, my friend experiencing the same thing, I looked into it more and actually found a thread on the forum where this crap ruined someones studio. Don't use it.

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
The Dread
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

Gotcha, Greg, thanks for throwing that out there, bunch of PL around here, almost went that route, but never jumped, thankfully.

I've been unable to find something from Home Depot/Lowes, etc, worth committing to. I definitely could use some advice regarding a source for quality, low cost sealant.
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Re: Looking for some insight regarding my garage build...

Post by The Dread »

...I have another question that keeps coming up in my head;

Would using resilient channel on whisper clips allow me to mount my interior leaf on the same framing/studs as the exterior leaf, and still achieve the decoupling benefits that I would achieve by building a new frame on the interior...

I realize the air space in between is critical to isolating performance, but I can't help but wonder how measurable the difference is, between the two methods I've described. Any thoughts, ideas, or recommendations?

Cheers, and happy Friday!
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Soundman2020
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Re: Looking for some insight regarding my garage build...

Post by Soundman2020 »

Would using resilient channel on whisper clips allow me to mount my interior leaf on the same framing/studs as the exterior leaf, and still achieve the decoupling benefits that I would achieve by building a new frame on the interior...
Firstly, resilient channel should not be used on clips: Clips are meant to be used with hat channel, not resilient channel.

But even if you could, the answer to your question is "no". You can't get the same results by using any form of mechanical decoupling. You get an improvement, certainly, but you can't get the same final outcome, for the simple reason that the mechanical "spring" and the air "spring" are in parallel: the worse one always subtracts from the performance of the better one. You get maximum performance with the air spring alone: anything you add into that will REDUCE the effectiveness of the air. In simple terms; the air spring is "soft", and the mechanical spring (the rubber in the clips, or the metal forms of the RC) is "hard". Adding hard to soft obviously does not make the total "softer" (which is what you want): it will always make it "harder". A simple analogy: Image that you have clean water in in a glass, and you add some type of colorant to it. No matter what color you add, it will never make the water any more transparent! It's already as transparent as it can possibly be. You can only ever make it LESS transparent.

And since the "springiness" of the "S" in the MSM equation is what defines the resonant characteristics of the wall, making the spring "harder" will never improve that.

For the same reason, there's a limit to the amount of isolation you can achieve from using clips+hat, or RC, and that limit is about 16 dB greater than what the wall would have achieved without the RC (or clips+hat). You can't get more than that: it is physically impossible, because of the mechanical connection. As rubber and metal technology improve, that might increase slowly to maybe 17 or 18 dB, or whatever, but it can't go much higher than that.

On the other hand, with a separate frame, the limits are much higher. Basically, there are no limits of importance for typical home studios: you'll run into other limitations before you run into the limitations of what a good MSM system can achieve.


- Stuart -
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