John Sayers' Recording Studio Design Forum Archive

Hello,
I am finally posting a drawing for a studio I have been planning for over a year.
Thanks so much for everyone who makes this forum a huge resource.

I am starting with a long narrow building with a footprint of about 10' X 20'. The roof peak is 11 1/2'.
The floor is concrete The exterior walls are pine ship lap over 3/8" OSB with a layer of Tyvek in between.
I am caulking cracks and beefing up between the studs.

In the end I would want to have a space where I can practice into the night with a band. I took an SPL reading at the last practice 110dB seems good for maximum volume.
My closest neighbor is about 25' away

I have been trying to decide between doing one or two rooms.
I have settled on a compromise involving a sliding door.
This would allow me to close the door to achieve a moderate amount of isolation. Or open the door when that won't be needed.

The interior walls would be inside out with 2 layers of 5/8" sheet rock with Green Glue between the layers.
The floor would be untreated concrete.
The ceiling options are:
A) 2 layers of sheetrock hanging from the rafters on RSCs. Less isolation, but more ceiling height (about 9 1/2' at the highest point)
B) Install ceiling joists hanging the sheetrock off of that and losing 14" of headroom gaining, I am not sure how much, sound reduction.

The plan is to have a mini-split system and fresh air intake/exhaust.
The dimensions of the control room are 9'6"X8'5" with a ceiling height of 9'
The live room would be 9'6"X11'6"X 9' high

Questions:

All things being equal how necessary is it to this design that the ceiling is totally isolated from the roof rafters?

Having little experience with sliding glass doors, does anyone have a recommendation for best sound reduction at the least cost?

Where do I put the freaking vapor barrier?

Any design suggestions would be helpful.

I read and reread Bigsby's build journal and have been getting a lot of good information there.


Thanks for your time!!

Here are some pictures of the space as it is.

Hi there " CyborgAudio", and welcome!

I am starting with a long narrow building with a footprint of about 10' X 20'. The roof peak is 11 1/2'.
The floor is concrete The exterior walls are pine ship lap over 3/8" OSB with a layer of Tyvek in between.
I am caulking cracks and beefing up between the studs.

IT sounds like you have a decent basic space to work with. Small, but usable.

In the end I would want to have a space where I can practice into the night with a band. I took an SPL reading at the last practice 110dB seems good for maximum volume.

Did you measure that with "A" weighting or "C" weighting? You should be using "C" for that. 110 is slightly on the low side for an enthusiastic rock band. Wjat instruments were being played?

The interior walls would be inside out with 2 layers of 5/8" sheet rock with Green Glue between the layers.
The floor would be untreated concrete.

If you are going that route (which is the best one) of doing a full room-in-a-room isolation system, then why not go all the way and do the same for the wall between the two rooms? You can greatly improve the isolation like that. You'd need two sliding doors like that, instead of just one, but your isolation would be anywhere between ten and a hundred times better.

The ceiling options are:
A) 2 layers of sheetrock hanging from the rafters on RSCs. Less isolation, but more ceiling height (about 9 1/2' at the highest point)
B) Install ceiling joists hanging the sheetrock off of that and losing 14" of headroom gaining, I am not sure how much, sound reduction.

I would go with "B" for the control room, since that would also solve the problem of the gabled roof, and would allow you to set it at the height that gives you the best ratio. But for the live room, I would do a second gabled ceiling that follows the same line as the existing roof, interleaving the new joists between the existing trusses to minimize loss of height. It's a bit more work to do that, but much better isolation and also much better acoustics inside the room, due the higher volume.

The plan is to have a mini-split system and fresh air intake/exhaust.

Correct. One mini-split in each room, one fresh air supply duct in each room, and one stale air exhaust duct in each room. That is, indeed, the correct way to do it. And with suitable silencer boxes on each duct, of course.

The dimensions of the control room are 9'6"X8'5" with a ceiling height of 9'

That's not such a good ratio. It's way outside the Bolt area. You could fix it by lowering the ceiling a bit: Bring it down to 8'2" and you have a much happier situation. That pretty much Sepmeyer's best ratio (1 : 1.14 : 1.39).

All things being equal how necessary is it to this design that the ceiling is totally isolated from the roof rafters?

That depends on how much isolation you need. If you don't need more than about 30-something dB of isolation, then just hang the inner-leaf ceiling from the existing trusses (assuming they are able to carry the large extra dead load: you'll have to check that with a structural engineer. Nobody else can tell you that). But if you need good isolation, 50 dB or more, then you'll have to decouple the inner-leaf ceiling from the roof. And you might have to do that anyway if the existing trusses cannot handle the extra load.

Having little experience with sliding glass doors, does anyone have a recommendation for best sound reduction at the least cost?

That's sort of like saying "Can anyone recommend how I can have very dry water that is also very wet?" In other words, 'good isolation' and 'cheap' are terms that cannot be used in the same sentence. If you want good isolation, then you will need acoustic rated sliding glass doors, which will likely cost you a couple of thousand dollars each. If you only want to spend a couple of hundred dollars each, then you'll get "cheap" but you won't get "good isolation"...

The reason is simple: isolation requires mass. The more isolation you want, the more mass you need, except that the amount of mass goes up exponentially, not linearly. And since sliding glass doors are, well... "glass", then the glass has to be very massive, meaning very thick, meaning not cheap. The glass commonly used on studio windows is 1/2" thick at least, commonly 3/4" thick, and often even more. Thick laminated glass is expensive, and when you need enough of it to completely fill four sliding panels, that's a lot of money you are talking about! On the other end, the typical cheap sliding glass doors that you buy in an average DIY home improvement store, have glass that is only about 1/4" thick, and is not laminated. So it does not isolate well.

So those are your choices: cheap, or good isolation. Pick whichever one you want, bu only one.

Where do I put the freaking vapor barrier?

The same place as always: inside the wall cavity, up against the warmer surface. For you, that probably means up against the inner-leaf, but do check with local building contractors and your local building inspector to find what the normal method is in your area.

Any design suggestions would be helpful.

You seem to have the right basic idea, but you could improve things by not angling the dividing wall between the CR and LR. Please also add the outer-leaf to your diagram, since right now it is only showing the inner-leaf. And also do the dividing wall as a proper 2-leaf wall taht integrates with the other inner-leaf walls.

Here are some pictures of the space as it is.

It looks like you have beefed up sealed the outer leaf walls, in between the studs, which is an excellent idea. Now you need to do the same to the roof deck, in between the trusses.

I guess he single biggest question that needs answering here, is how much isolation you need, in decibels? based on that, the rest is a lot easier to figure out!



- Stuart -

Hi Stuart,
Thanks for your response!
I like the idea of the gabled roof in the LR and improving the ratio in the CR.

Getting rid of RSCs would help expenses.
I have to find money for the second set of sliding doors.

I'm more concerned with isolation between inside and outside and those doors are crazy expensive!

My intention for angling the shared wall was to have the walls of the control room angled and have as much usable space as possible in the LR.
How would not angling the wall improve the design?

Here's a question: As I continue working on the studio into the winter and temperatures drop below 40º F Should I hold off with the Green Glue until it warms back up
in 6 months?

Again, I appreciate the indespenable work you do on this forum.

Jed

Hi!
I'm just getting started on interior walls.
I met with one HVAC company about installing a mini split system.
I am concerned about coupling the inner and outer membranes with the copper lines.
The company would rather go straight through the two walls, but that seems like it would cancel the two walls.
Is it possible to pass the tubes through without creating a connection between the walls?

The company would rather go straight through the two walls, but that seems like it would cancel the two walls.

Right! It would.

Is it possible to pass the tubes through without creating a connection between the walls?

Yes: Curve the pipe bundle as soon as it passes through the inner-leaf, so that it runs parallel to the wall for a few feet, then curve it the other way again, and pass it through the outer leaf. As long as there's a few feet of pipe in between the two penetrations, and the pipe bundle does not touch the leaves in that area, then there's enough "springiness" in that to decently decouple the pipes from both leaves. There's plenty of room to curve the pipe bundle gently without kinking the pipe, as there should be something like 7" (or more) of cavity between the two leaves. One thing you do need to be careful of here is that the condensate drain pipe descends all the way: the other pipes and the cable don't matter: they can go up, down, straight, or even around in circles, but the condensate pipe drains water by gravity, so it needs to slope down slightly all the way.


- Stuart -