Framing & Drywall for a vaulted ceiling, inside-out studs

[jamesattaway]

I had the hardest time trying to search and find anything on this, so I thought I'd ask the question.

Here's the requisite details:

I'm building a studio in the garage of a house where the record label that employs me has their offices. I'll be recording drums, bass, electric guitars, and other loud things (rock music). We're putting everything in the 2-car garage, while still running cabling to the basement and attic for guitar amps. I would like to avoid running into problems with large trucks passing by (only 50' from the road where large trucks drive by), but I'm not worried about bothering the neighboring offices too much. Our budget is roughly $30-40k.

I'm also working with our ministry's construction and maintenance department; they've been very helpful in answering my questions about construction details and working through every nuance so we can get this bid out to a contractor. We're still in the planning phase, but details need to come together quickly so we can get proper architectural plans drawn, permits, etc. for the bids.

I'm planning a 2-leaf design with 2 layers of 5/8" sheetrock on each, a layer of green glue sandwiched in between, and the proper acoustic sealant as per the reference area. I have "Home Recording Studio: Build it Like the Pros" by Rod Gervais and have read through it several times, applying the proper concepts.

((Side note: One thing I like about this forum is that it fills in some critical caulking details that I couldn't find in his book.))

The current garage's ceiling is 8' high, but that will go away, leaving nothing between the roof (no trusses) and the concrete garage floor. The end of the building where the garage is has a peak until halfway into the garage, and then a hip down to where the garage doors are.

We'll demo the sheetrock on the inside of the exterior wall studs to expose the wood exterior behind, and add layers of sheetrock in between the studs. We'll build a new, vaulted ceiling that's attached and sealed to the exterior wall to form the outer leaf. Our inner leaf walls will internally-support the inner-leaf ceiling, which is vaulted in the tracking space and raked in the control room.

After trolling around here for a few years, I've noticed that the inside-out wall design is very popular and practical, giving more space for acoustic treatment on the inside of the walls, fewer penetrations of electrical jacks, etc. I think that would work great for me, but I can't grasp how to actually build the wall, attach the drywall AND seal the joints as per the reference area's recommendations (http://www.johnlsayers.com/phpBB2/viewtopic.php?p=20003).

As it applies to my project, I'm wanting to do the inside-out wall for at least the left-most (eastern) wall in the tracking space, and possibly all the walls in the iso booth.

If you frame the inside-out wall on the ground, and put on the drywall face-up and then tip into place, how do you seal the corners to the next inside-out wall/ceiling? Or even that wall itself to the floor?

How should the caulking go if the adjacent interior wall/ceiling has the drywall on the INSIDE of the studs?

Thanks for all your help! You guys are such a valuable resource!

James

[Soundman2020]

Hi James, and welcome to the forum!

Just some quick comments, no particular order:

I would like to avoid running into problems with large trucks passing by (only 50' from the road where large trucks drive by),

Have you measured that, to see how much of a problem it is? In terms of frequency and SPL, I mean, so that you can plan accordingly. Very low frequency rumbling isn't easy to deal with.

so we can get this bid out to a contractor.

Make absolutely certain that the contractor you get has ample experience building studios, and is willing to let you see places he has built / talk to the owners!!! Thiis is probably the single most important decision you will make with your build. If I had a dollar for every horror story on this forum where people hired ordinary contractors (no studio experience), and ended up with a major disaster on their hands ...

Building a studio is NOT like building a house, office, shop, school or church. Any contractor who tells you other wise should be dismissed out of hand: not even worth talking to him. Same tools, same materials, but very different techniques. If they get it wrong, they can very literally trash your isolation, and harm your room acoustics. So if you are not the person making the decision in which contractor to hire, it would be in your best interests to talk to the person who is, and explain this point in abundant detail to make sure they only hire a contractor with proven studio experience. I can't over-emphasize this enough. A contractor who has never built a studio might offer a cheaper quote, ... but only because he doesn't understand what he is up against! And it will only be "cheaper" for you up front.... When his build doesn't work, and you have to tear it down partially to fix it, that's when you'll feel the pain.

If the person who makes that decision in your organization is skeptical of this, I'd be happy to point you at a few threads where people have had to do exactly that: tear things down and re-do them right. Sad, but it happens fairly often.

If you hire a contractor with no studio building experience, then you will be a guinea pig. If you like being a guinea pig, and don't mind spending extra time and money to re-do that parts that the contractor gets wrong, then by all means, be a guinea pig!!!

Caveat emptor.

details need to come together quickly

That might also be a mistake: designing a studio is way more complex than designing a spare bedroom or new kitchen. Vastly more complex. There are so very many things that need to be thought through carefully, and any one of those can wreck the result. It's fine to want to move fast, but it's not fine to rush or hurry, and it is most "un-fine" to cut corners. There are several red flags on your current design, just at first glance, that need fixing. That leads me to suspect that the plan isn't ready for prime time yet. Moving ahead based on that will not get you where you are planning to go, I suspect.

that will go away, leaving nothing between the roof (no trusses) and the concrete garage floor.

How high will that be then? And what is the actual roof made of?

and then a hip down to where the garage doors are.

What is your plan for dealing with those garage doors? Take them out and brick up the whole? Or seam them in place permanently and build a middle-lead around them?

We'll demo the sheetrock on the inside of the exterior wall studs to expose the wood exterior behind,

Great, but how is that outer leaf built? You mention wood, but what type? How thick? What's on the other side? How will you handle the vapor barrier issue?

We'll build a new, vaulted ceiling that's attached and sealed to the exterior wall to form the outer leaf.

Actually, that will be the middle leaf, not the outer leaf. You already have an outer leaf: the roof. So you will be building a three-leaf system. That's unavoidable in your situation, but since it is a 3-leaf, it needs to be designed with that in mind. What size air gap are you planning to leave between the roof and the middle leaf, and how much mass will be on each?

Also, how do you plan to deal with the roof deck ventilation issue?

If you frame the inside-out wall on the ground, and put on the drywall face-up and then tip into place, how do you seal the corners to the next inside-out wall/ceiling?

At the corners, you seal the STUDS together, not the drywall. You can't get to the drywall corners on inside-out construction to seal them, obviously, but that doesn't matter. The drywall leaves on the two walls don't even have to meet each other at all: They just need to be sealed firmly to the studs. There is far more surface density in the studs themselves than there is in two layers of drywall, so there is continuity of mass around the corner (as long as you use straight studs, so they mate together neatly). So you seal between the mating studs as the wall goes in place, then nail, bolt or screw the studs firmly together.

Or even that wall itself to the floor?

Three beads of caulk go down on the bottom of the sole plate before you raise the wall. One bead down the center-line, and another bead about an inch either side of that, along the full length of the plate. Plus another bead along the bottom edge of each layer of drywall. Then when the wall is up, put another bead along the front edge, for good measure. That gives you multiple seals under the wall, which is a very good thing.

How should the caulking go if the adjacent interior wall/ceiling has the drywall on the INSIDE of the studs?

Same as above: first, seal the mating studs. Then caulk all the way up the front face of the last stud before you put the drywall on, then use backer rod and caulk in the gap between that drywall and the stud on the wall next to it. Assuming your corners are framed correctly, the edge of the drywall on wall "A" will butt up against the face of a stud on wall "B", so you cut it a bit short, then fill the gap with backer rod, and caulk

Hope that helps!

- Stuart -