John Sayers' Recording Studio Design Forum

Hi Rod,
Thanks so much for helping clear this up. I have been reading and re-reading your "Build It Like The Pros" book for the past month or so. The one line that really sold me on your book is was when you explain your motto: "tried, tested, and true." And that you'd never recommend something that is not backed up by solid lab test results. I respect and appreciate that.

Anyway...

I wanted to clarify your recommendation: So you are confirming that the adding layers of 15"x8' drywall strips (with acoustic caulking around the perimeter) between the 16" O.C. studs, on the backside of the siding, is a reasonable solution to the situation I'm in? I'm specifically referring to when you said the stud surface for that area would have slightly less isolation properties compared to the drywall "but not significant enough to warrant covering the outside of the siding with drywall and residing the building."

It seems that both you and xSpace are saying the mass between studs idea would be a reasonable alternative to adding full sheets of drywall to the outside.

xSpace and Rod, thank you again for helping a newby achieve his goals.
Sincerely,
-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

Doyle,

that is exactly what I am saying - it is clearly illustrated in the case of floors - for all intent and purpose floors are walls turned on their sides.

Rod

_________________
Ignore the man behind the curtain........

Great!

Two installation questions:

1) Since the devil is in the details, any tips on how best to install these strips of drywall between the studs? I was thinking about installing two layers of 5/8" fire rated drywall and then buying nails that are 1 3/4" long and nailing the drywall right into the back of the siding (two sheets of 5/8" drywall + one sheet of 5/8" siding = 1 and 7/8 inches.) FYI: I have attached a pic of what I see on the inside between the studs. It's basically the Tyvek moisture wrap and then the 5/8" Duratemp primed siding.

2) I once read a post on here where someone talked about getting free damaged drywall from a company who would have to pay to have their damaged drywall picked up. They were more than happy to give it to a customer for free. I can't seem to find this post again. Since I only need 15"x8' strips to fit in between the studs, I thought this might be a good option. Anyone have any experience with this? (If not, then I'll just go and buy the new sheets and cut them up in strips.)

I think this post will be valuable to other people who happen to be in my situation and want to know how to build up their first leaf without removing the siding. Thank you all for helping me through this.

-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

Doyle,

Your situation is common place. There are dozens of threads on Johns forum that have this very same issue. I think the time has come to get into the search function...spend a few weeks getting the information that you want.

It's in here, you can believe that, and I trust that you can find it.


As you said, the devil is in the details so you miss much detail by not spending more time getting your mind wrapped around your build particulars.

You can believe that there are going to be so many questions that will come up that you can run off the forum members, if you do not help yourself just a little bit more


If you require more reading material, I may be able to suggest something to a particular aspect or topic.


Go Bama!

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

I guess it was pretty naive to think I was the only one who thought of the mass between the studs idea. Thanks for the gentle nudging to do a peer search and see how they solved the problem. It seems these fellows have pursued the same route but haven't disclosed their installation secrets:

viewtopic.php?f=2&t=11636&hilit=mass+between+studs

viewtopic.php?f=2&t=13795&p=95899&hilit=mass+between+studs#p95899

viewtopic.php?f=1&t=13158&p=90663&hilit=mass+between+studs#p90663

Still searching for best installation for drywall-between-the-studs but I'm confident I'll find it.

-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

Doyle,

I hate to say it... but remove the siding and do the job right.

You'll regret it in the long run if you don't.

Whether you do the job right or not, when you stuff the cavities with the 5/8" gypsum, you should stuff the edges with backer rod and caulk them. Then go back and cleat them in around the edges with something like a 1x2 furring strip, then caulk around the edges of the furring:



In my build, I added two layers of 3/4" OSB to the stud surface, then the housewrap, then Hardi-Plank. The interior got 5/8" FR gypsum (pic above) and filled the cavity with insulation (Craft face to the exterior) – 1" air gap – Interior stud wall.

By failing to go back and put more mass on that exterior stud face, you can potentially end up with structural noise you can't go back and fix... e.g. IF the gypsum does not edaquately contact the surface of your siding, there is not enough material thickness in the siding to screw the gypsum to... to eliminate any mechanical buzzing/vibration.

Sorry to be the bearer of bad news and extra work... but do it right. You won't regret it.

(If you want to review my build, this all happened in Oct-Dec 2007, Jan-March 2008.)

_________________
Good stuff ain't cheap and cheap stuff ain't always good.

Studio Build Insanity: DM Mobile/Dark Pines Studios
(A Rod Gervais Designed Room)

I don't see removing the siding as part of a 2500.00(USD) plan. Not only will it tear and distort the entire appearance of the engineered plywood which makes it kinda ugly now, it is a simple build in a persons backyard that doesn't take the time to read and get fully prepared for this project.

Yes, that would be better as you have suggested Max, but it's "too much sugar for a dime".

His build is an 8 foot X 12 foot X 16 foot...at least one dimension is divisible by another. That only means that whatever acoustic issues arise from the 8 foot, the 16 foot wall compounds it.

I think he should tear the whole thing down to the slab But there has to be a point where you learn the lessons that haste teachs and you move forward.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

I don't see it happening either... however, I know Doyle's budget of $2500 is about 1/4 of what the real final numbers are gonna be> and I'd just like to point out that doing the right thing now will keep the $2500 from being less than 1/8 of the final cost... due to reworking everything at least two or three times.

I suppose he could put on an additional layer of 3/4" plywood/OSB over the existing siding, and then put another layer of T-111 over that... but then you have the issue of the housewrap acting as a mold trap, holding too much moisture between the studs and the extra layer of housewrap that should go on over the 3/4" sheetgoods... or.. he could go ahead and cut the housewrap off the stud bays now.

No matter what, continuing on in this manner is not going to yield a very soundproof structure.

_________________
Good stuff ain't cheap and cheap stuff ain't always good.

Studio Build Insanity: DM Mobile/Dark Pines Studios
(A Rod Gervais Designed Room)

Granted the house wrap is in the wrong position, but I am not certain it is as much an issue as thinking might suggest.

It isn't a barrier and allows air/vapor movement as a retarder, from either side of it. As a water plane it still shouldn't trap due to the ability of the house wrap to breath.

Just one of several places the OP has missed establishing a proper building first, and a solid foundation for an acoustically correct building, second.

I do agree, as you mentioned, that if additional siding were to be added then removing the tyvek from the interior side[cutting it out between the stud bays] is a great idea and then to install it[tyvek] over the existing siding, which would in effect reduce the existing siding to the position of being the sheathing.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

QUOTE: "it is a simple build in a persons backyard that doesn't take the time to read and get fully prepared for this project."

Honestly I am starting to get frustrated with these comments pertaining to my lack of preparation. I completely acknowledge that I am not an expert in studio construction, I am not even a good handyman, or even great with math. I am a professional musician (college educated and trained) and that is my expertise. I tried to do the best research I could (for two months prior to starting any construction). I bought two books that got good reviews (including Gervais') and consulted a seemingly well-respected "studio construction professional" here in LA who charges $500 an hour for his consultation (one phone consult and one in person where I showed him my blueprints).

Not only have a I have found my professional consultation advice to be conflicting to the "expert" advice I find on here but I flat out can't even find straight answers to the questions I do ask. I put the vapor barrier where my "studio consultant" said I should. How was I supposed to know the vapor barrier was in the wrong place? Everything I read and everyone I spoke to only covered how it's best to add mass to the side on which the sound is being produced (ie- the inside). It wasn't until after I framed and added the siding that people starting mentioning beefing up the outer layer. What else could I have done? I got the consultant, I read the books, I tried doing the preparation.

QUOTE: "His build is an 8 foot X 12 foot X 16 foot...at least one dimension is divisible by another."

I already knew before I started that my 8ft ceilings were a multiple of the 16ft length and this is bad. I would have preferred a bigger room but this was as big as I could afford. I was told that the peaked ceiling wouldn't be as bad as having a flat 8ft ceiling and that I could further help the situation by splaying the walls on the inside. But I'm not there yet, I'm just trying to prepare the outer leaf situation.

So far in this one post I've had 3 different solutions to my problem and all of them claim to be the best, considering the situation:
1) Add mass between the studs. (which Rod and xSpace endorse)
2) Tear down the siding and start over. (xSpace thinks would be a waste, considering)
3) Leave the siding and add more mass to the outside. (vapor barrier/mold issues???)

QUOTE: "I think he should tear the whole thing down to the slab But there has to be a point where you learn the lessons that haste teachs and you move forward."

I honestly made a significant effort to be prepared for this project. I get the feeling you think I am trigger happy and can't wait to make my next error. In hindsight I don't know I how else I could've prepared. Even though my plans were not the best I made the effort to educate myself and get expert advice. How else could I have known it wasn't ready?

I am grateful for all of your advice. I truly am. But sometimes I think you forget that even though you see this as a black and white science, it is all too often painted in a lot of grey. I'm just trying to sort it all out and make the best of it all.

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

I feel your pain boss. It is difficult to build, as anyone with any amount of time in the field will tell you and it is difficult times 10 to do it for an acoustical environment...as anyone who has done it will also attest.

I do not know what questions you have asked that have not been answered. I can say this. Rod Gervias is the author of a book that many say is a bible of sorts for doing this type of building. Madmax [xamdam] is a highly qualified construction technician in his own right and he is the GC[general contractor] of a high dollar and highly visible studio in North Carolina. Maybe the best that his part of the country will see.

Building, as a rule, is not a simple thing that people talk about and then do. I have been in commercial and residential building for over thirty years and still have to ask questions and read up on things as they tend[ the things that are part of construction] change all the time.

You can confuse terms easily in this business. As you are doing right now saying "vapor barrier".
The house wrap is not a vapor "barrier". It is a retarder And there is a large difference between what the one does versus what the other does.

Your retarder is fine, could be better, but it will work as is.




Actually, you asked about it. I think we can all get on board that the addition of layers is a good idea supported by documentation. What would have been better, had you paid us the money rather then spending it outside of this forum, that the EXTERIOR of the structure needs the most or at least equal mass....contiguous or unbroken.

Then there is the air space that suffers due to the addition of mass behind the exterior sheathing/siding. The air space is as important as the mass. You mentioned using RC. This is fine if this is what you want to do. But there are other ways that you could do this job that will get the isolation you require.

Even a simple study on RC will reveal that the low frequency will suffer and this is not the part of your isolation that you want to have a leak in with drums.

There are many trade-offs. This is why it is so important to begin with a firm foundation.

Have you ever built a house? The details can, as a builder, cost you any profit if it exists these days. So as a D.I.Yer, to suggest that you can get an isolated acoustic environment constructed without any errors...without any technical ability on your behalf, is pie in the sky.






Not bad, just something to avoid in the early phases of development if at all possible. It can be overcome. Remember, this is just a small room in your backyard, not a multi-million dollar exercise in acoustics.




These are not three different items, but choices to different degrees.




You have a few months in preparation. Many come here with this same notion. Personally, it is a disrespect to builders world wide in my point of view that people think they can D.I.Y. a building and not have any experience what-so-ever in building. It is, to me, the same as me thinking I can jump up on the stage at Carnegie Hall and play to a high caliber of execution on my musical instrument when I have only read a book or two about it and practiced for a few weeks.

Understand what I am saying?




This should always be done in preparation, not in retrospect.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.

Hey xSpace,
I appreciate the reply and I can completely respect your analogy for builders as compared musicians playing Carnegie Hall. My logical answer to that would be that it takes years of practice and experience playing lesser venues to successfully perform at Carnegie. Which in turn would mean years of practice building studios and experiencing what works and what doesn't. I can completely respect that and I meant no disrespect to professional builders by attempting this myself (though it's not as though I am selling my services as a building contractor).

But with this analogy comes the conclusion that I should never attempt this unless I am willing to dedicate years to learning the proper skills, gain the experience, and study the science of acoustics. In some regards maybe that is true. But that can't really be the end of the story. Otherwise this forum wouldn't exist.

I am all about being prepared and knowledgeable before spending a single dollar on anything. I honestly thought I had properly prepared my plans, at least enough to get me through the foundation and framing at which point I would focus on the next stage and make sure I was prepared before moving forward with that. I did not expect to screw this up so early in the process.

Also, just to clarify, when I say "I" what I really mean is "they." I'm hiring out most of each phase of this to professionals in concrete, framing, electrical, HVAC, etc. I am doing my own caulking and probably drywall (I have some experience there). But I've read enough horror stories to know that you can't expect non-specialized professionals to know the details required in sound isolation and that's why I'm trying to learn as much as I can so I can communicate my needs to them effectively. In some regards I guess it's the blind leading the blind, ay?

My comment about not getting my question answered wasn't clear. I didn't mean that I was ignored, what I meant was that I got 3 different "degrees of choices", as you put it, and I mistook them for contradicting solutions to my situation, with no clear answer. My expectations got in the way of my understanding. Sorry 'bout that.

By the way, I finally found the answer to my installation question about installing it between the studs. After PM'ing a few people about their posts, I found they used a combination of screws into the back of the siding with 1x2 furring strips around the edges of the drywall (with backing rod and caulking between the edges).

Thanks again for your patience and guidance.
-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

Hi xaMdam,
Thank you for posting your experience with this. To prevent having to remove all of my siding, I wanted to ask you a follow up question regarding the structural vibrations that you are referring to:

If I am picturing your statement correctly then your concern is that the drywall between the studs might vibrate against the back of the siding if not properly secured, is this right? If so, could a solution to this be a thick layer of acoustic caulk on the back of the drywall that goes against the siding? This layer of caulk could absorb the vibration noise and provide a barrier between the two surfaces rattling against each other.

Or in addition to that, perhaps I could add a few more strips of 1/2" trim that could run parallel with the existing trim but positioned more in the middle of the outside wall and act almost like a backer board for the inner drywall to screw into. That would provide 1 1/8" of mass (1/2" of trim + 5/8" siding) for the drywall to anchor to. See attached 3D sketchup.

I know this isn't the preferred method by any stretch but I'd still appreciate your opinion on this.
Thank you,
-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt

Doyle,

What I did (and still do), as have many others I'm sure... is all through the building process, tap, pound, and generally beat on surfaces and assemblies; with a hammer, block of wood, your fist, foot, shoulder, or other blunt object. (My head in particular... MANY times... but that's another story altogether.)

When you come across a vibration/buzz/rattle... address it RIGHT then. Stop the buzz and you eliminate issues with LF doing it after the fact, when it's impossible, or extremely costly to fix later.

When I was adding the gypsum between the stud bays, I had a of them that rattled and buzzed a bit too much for my liking. So, I simply sank a screw in the panel to tighten it up. I didn't drive a bucket of screw in the panels.. just one or two to sock the layer down to ensure it would dampen sound as it reached the panel.

You can use acoustic caulk, I guess... but, personally I wouldn't. If I was going to do anything like a caulk, I'd use Green Glue. HOWEVER, Green Glue is NOT a cheap option.

"Acoustic caulk" is used primarily as a means to stop air flow... not as a damping agent.

I suppose you could use PL200 or a similar construction adhesive, but again, construction adhesives become hard, like a nail/screw, but they tend to scare me from the aspect that they aren't as secure of a physical bond, and in my (albeit limited) experience, tend to fail to adhere after repeated heating and cooling cycles... as in long term temperature changes in an exterior wall cavity.

GENERALLY, when you are putting mass assemblies together, you are trying to achieve one of two things... you are using smaller/thinner masses to become bonded to create a single additive mass, or you are bonding different masses in a way to allow part of the mass assembly to act as a damping layer.

If your intention is to use the gypsum to act as a damping layer between the stud bays, then you want the gypsum to be as tight against the outer sheathing as possible, without a solid connection to the sheathing. This small air gap will allow the gypsum to vibrate, yet dampen the gypsum as it transmits energy to the next layer... which then allows the gypsum to dampen the next layer. Adding a bunch of screws to the gypsum to secure it to the sheathing will minimize this damping effect, as it will form a unified mass.

Creating a unified mass isn't such a bad thing, in and of itself... it's really only a "bad" thing if you are dependent upon the layer to be a damping layer.

By adding an additional damping agent, such as Green Glue, you will get a superior damping performance in the LF range... again, at a significant dollar cost.

Since your walls are 2x4, you can probably only get away with adding 1 layer of gypsum to the stud cavities. Any more than that, and you are going to loose a significant amount of air cavity volume... which can then only be made up by increasing the air cavity, and therefor reducing the square footage of your rooms.

However, if you are willing to forgo room volume in lieu of beefing up the exterior layer, I'd potentially use 2 layers of gypsum and use Green Glue between each layer of gypsum; gypsum, green glue, gypsum, green glue, housewrap, sheathing.

I would NOT assume that this is a viable option without getting confirmation that this is indeed viable. This will at the very least add the additional cost of 6-8 cases of Green Glue to your budget... and at $250/bucket, you just added at least $500 to your budget, plus the cost ($50-ish) of a decent caulk gun.

Again, this is what I was referring to about your $2500 budget getting shot to hell, real quick.

_________________
Good stuff ain't cheap and cheap stuff ain't always good.

Studio Build Insanity: DM Mobile/Dark Pines Studios
(A Rod Gervais Designed Room)

xaMdaM,
Thank you for that detailed reply. Being a drummer I will totally take your advice on banging on my building whilst listening for unpleasant tones. This will be a like constructing a big drum!

I definitely see your point about the budget. Getting the RSIC clips, hat channel, 8 tons of green glue and several layers of FR drywall will definitely exceed the $2500 I had set aside for this part of the project. Time to reconfig the budget.

On another note, I'm trying to confirm the best order to do all of this. I talked to a studio contractor yesterday who said that I'd need to install the double-door last (after all the walls are completed). This does kind of make sense but I wanted to ask ya'll your thoughts.

The way I'm thinking of it is in this order:

1) foundation/framing (completed)
2) drywall between studs to add mass to 1st leaf
3) electrical
4) HVAC
5) RSIC-1 clips/hat channel install
6) 3 layers of drywall with Green Glue between each layer
7) install double door entry last?

Thank you,
-Doyle

_________________
"Great minds discuss ideas; average minds discuss events; small minds discuss people."
-Eleanor Roosevelt