Inside Out Vaulted Ceiling Installation

[silky smoove]

I'm in the relatively early stages of a new studio build in Seattle. In a previous thread (http://johnlsayers.com/phpBB2/viewtopic.php?f=2&t=20544) Soundman2020 absolutely turned my designs on their head (thanks again for all the help Stuart!) and I'm now proceeding with inside-out walls and ceiling to finish out a room that is roughly 19' long, 13' wide, 8' tall at the top plates where the wall meets the ceiling, and 9'-8" tall at the peak of the vaulted ceiling.

As I alluded to in the last paragraph; The existing structure has a vaulted ceiling. I'm planning on building the inside-out walls, and then spanning the room (approximately 19') with an LVL beam supported on the north and south ends of the room. From there I'll be constructing an inside-out ceiling that spans at an angle from the LVL beam down to the top of the inside-out walls.

The part I'm having a hard time wrapping my head around is how people physically lift the inside-out ceiling "modules" or "panels" into place. Conceivably with all of the lumber, and in my case two layers of drywall with Green Glue in-between, each portion of the ceiling will be exceedingly heavy. Do people usually handle this by getting a team of people and ladders together to lift it into place? This seems very unwieldy, difficult, and potentially dangerous considering at least two people will have to work off of ladders. Is there a type of lift or hoist that would make this task less labor-intensive, and hopefully more safe? Am I missing something obvious in terms of how to do this installation correctly?

Thanks!

[Soundman2020]

There's several ways you can do that, depending on the weight of the modules and the height they need to be lifted to. Some drywall lifters can handle pretty decent loads, you could use winches ("come-alongs"), you could hand lift, and at the other end of the scale you could rent a small forklift. There are other options too. A good contractor would be able to give you advice on that.

The important thing here is safety: you do not want a module weighing many dozens of kilograms to fall on your head from 10 feet up! Use safety ropes, bracing, etc. to ensure that the thing cannot fall, even if the lifting equipment fails. Make sure there is nobody underneath when modules are being lifted, everyone wears appropriate safety gear (hardhats, steel-toed work boots, gloves, etc.), and one person is clearly in charge, directing the lift. Use the typical safety tips you'd see on any commercial job-site where over-head work is taking place. Heavy things high up are dangerous! Take abundant care.

- Stuart -

[silky smoove]

I did a little math to see how much each panel would weigh once assembled and ready to be lifted into place.

Assuming 2x6 lumber weighs roughly 2lbs/ft, drywall weighs roughly 2.31lbs/sf, the insulation for each panel will be just over 5lbs (total), and then adding a little allowance for the Green Glue of which I could not find a weight per foot; I think 275lbs per panel will be a pretty safe bet.

That's a lot of weight in a pretty awkward configuration, squeezed into a tight space, by a group of guys on ladders. Yikes... Still not feeling great about this, haha. I'll take the risk to save ceiling height in the finished room.

EDIT: I'm not sure why I was bothering with 2x6 lumber on the ceiling. I could easily get away with 2x4s for that which will cut down some weight and allow for slightly more ceiling height.

[Soundman2020]

EDIT: I'm not sure why I was bothering with 2x6 lumber on the ceiling. I could easily get away with 2x4s for that which will cut down some weight and allow for slightly more ceiling height.

I'm also not sure why you are making your modules so large, and thus heavy and unwieldy!

Yes, use 2x4's for the actual modules, but the "backbone" framework that the fit into will have to be substantially larger dimensions. Likely 2x8, or even 2x10, depending on the span, load, type of lumber, etc.

- Stuart -

[silky smoove]

I'm also not sure why you are making your modules so large, and thus heavy and unwieldy!

I was attempting to do the whole room with just four modules which would minimize the number of cut sheets of drywall, as well as the number of adjoining modules that would need to be sealed together. I could easily reconfigure my plan to have three modules per side, or even four, and will definitely consider doing so to make the installation more reasonable.

[Soundman2020]

I was attempting to do the whole room with just four modules which would minimize the number of cut sheets of drywall,

Cutting drywall is dead easy. There is nothing that is easier to cut, actually, among building materials. If you make modules half the size, you would just cut each sheet across the middle. It would take about ten seconds...

as well as the number of adjoining modules that would need to be sealed together.

I'm a bit concerned about that comment, since the modules do not join to each other! They don't touch each other at all, when raised.

Please post your plans for the ceiling, so I can check what you are planning to do up there. Maybe I misunderstood your comment, but it would be safer to check.

It might seem like a lot more work to raise twice as many modules, but if they are very heavy then it is actually easier and faster (and also safer!) to go with smaller modules. Larger modules would also be spanning larger distances between joists, so you'd need larger dimension lumber for your joists. I try to never have the joists more than 24" apart, as that's about the maximum you can do safely with reasonable lumber sizes for typical home studio spans.

I could easily reconfigure my plan to have three modules per side, or even four

That must be a rather small room, or your modules are way too large! I commonly end up with more than a dozen modules for a typical control room, and 30, 40, 50 or even more for a large live room. Even a vocal booth would have three or four.

I suspect that there's an issue with your plan here, so please do post it.

Your original thread shows a room 19' long by 13' wide. Assuming you span the shorter distance with sistered 2x joists @ 24OC, you'd need 9 modules along the length. You'd also need 3 modules across the width @ 48OC, but that wouldn't work out since your ceiling is symmetrical, so you'd really need four across the width, two on each side of the centerline. So, 4 across by 9 down = 36 modules. I can't see you doing it safely in less than about 30 modules. So when you say that you want to "increase" the number of modules to "three or even four" on each side (total of six or eight), then there's a major problem with your design! You seem to be misunderstanding how to do this...

- Stuart -

[silky smoove]

I suspect we're describing different things with the term "module." I'll describe what I mean by "module" and see if we can get on the same page.

The interior of my structure is currently 2x6 exterior walls spaced 16" on-center with double top plates and then scissor trusses spaced 24" on-center on top of that. As you pointed out in my other thread the attic space above the chord of the scissor trusses is vented at the eaves, so a three leaf ceiling will be required. To achieve this I'm going to be attaching two layers of drywall, possibly with Green Glue between if it would be a significant benefit, to the bottom of the scissor trusses, thereby creating the middle leaf of the system. I'll be constructing John's inside-out walls around the perimeter of the structure to decouple the walls from the exterior structure. I'm planning on spanning an LVL beam between the two gable end inside-out walls.

The "modules" that I'm describing would essentially be of similar construction to the inside-out walls (drywall on the side farthest away from the interior of the room, then lumber on the inside acting as the inside-out framing as well as creating bays for acoustic treatments). So in this case it would be a series of 4-sided frames with drywall on the backside (probably two layers with Green Glue) and however much internal lumber would be required to achieve an adequate spacing for a given span.

Regarding them touching, or not touching: It was my understanding that the decoupled structure (i.e. the smaller room inside the larger room established by the exterior walls of the structure) would all be framed together such that the inside-out walls and ceiling would all be one decoupled framing structure.

Thinking about what you said, I might be approaching this differently than you would, so let me float a hypothetical and see if you think it would be a better way to construct the inside-out ceiling: Would you instead use joist hangers to install the framing for the inside-out ceiling, and then build individual modules using four pieces of lumber (possibly with a piece at the mid-span to brace it) and then place them in each joist bay?

I'll try and grab some images from my SketchUp model to better illustrate what I'm describing in a bit.

[Soundman2020]

The way I normally do it is creating a "backbone" of sistered joists, 32 OC that span the width, with 48 OC cross bracing, then build modules that fit in between that. Each module is a 2x4 frame with one layer of OBS on top, and a layer of drywall on top of that. The modules do not attache to each other! That would be unsafe. No structural integrity. Instead, they attach to the "backbone" frame.

I can't think of a simpler way of describing it.

What you are proposing is creating modules that are much too large, and way too heavy, to be raised safely. Keep your modules small enough to be workable. and raised safely.

- Stuart -