Stand alone "room in a room" studio build in Orange NSW Australia

[gearjunk1e]

Glenn

Valid questions

...as to my wife's wages, she knows that every piece of assistance brings forward the date when her car can again access the garage space which is full of building materials AND my ever increasing volume of recording/musical gear exits the house proper (Although I am also taking her out for movies/dinner tonight)

As to the ceiling, I'm doing an inside out; fyrchek at the top of those LVL joists on a frame with plastic wrapped insulation below, then muslin cover. Cabling runs in these spaces - inside the room but hidden. I'm currently installing one of the modules so will post some pics later but essentially following Stuart's reference blog https://forum.digistar.cl/viewtopic.php?f=12&t=50 but the rakes in my ceilings ruled out the large modules so I have lots of smaller ones and am currently working out whether its quicker to do them at ground level and lift or in situ - I have to do some in situ anyway - ie where the flat sections changes to rake as you can't lift one into place from below and under the silencers.

Both silencers sit above treatment areas - the return behind the soffit for the flush mounting of my Adam A7x's and the supply above/within the bass trapping at the back of the room. If my sketchup model wasn't in such a state of mess, I'd post that for clarity's sake. This design also gives me places to "hide" stuff away.

Hope that answers the question - thanks for keeping an eye on me.

Andrew

[gullfo]

no worries. just a note from when i do designs, even with inside out ceiling, is take advantage of ledgers to conform the positioning of stuff i need to lock into place and want them installed as a single unit. using metal straps to secure them all around. then i typically add the large(r) soffits for more absorption, installing side wall lighting, cove lights, access panels for wiring. filters, etc etc and also reduce some of the absorption needed on the walls (freeing up potential floor space and places for equipment).

[gearjunk1e]

Glenn
I know what a ledger board is (in the context of decking) but can't quite work out how it would look in this application - have you got an image of what it would look like?
Andrew

[gullfo]

this:

[gearjunk1e]

this:

Thanks Glenn - got it (I'm a visual learner)

Continuing the silencer story....

Connecting the ducts
The harder one was the supply end due to the space and that I was working with limited view. I had one crack at getting it on and ended up with mastic everywhere but couldn’t get the flex-duct over the whole of the collar. I cleaned off as much mastic as I could from the collar, let it cure for a few days, cut off the end of the flex-duct that was covered in mastic and tried again a few days later. This time I put aluminium tape around the last 2 inches of the flex-duct to hold the flex part out straight. Success! Give it a few days to cure then tape and attach a couple of o-rings.

My work space - the flex duct is a little less expanded than I would have liked but I do need to move the silencer 4" along the wall before securing, its a short run and I can cope with a little more static pressure in the system on this room

At the return end I had to scoop out a small semi-circle in the top of the LVL joist in line with the duct entry point to give me enough room to attach the flex-duct.

QUESTION
The clearance between the spigot and joist for the return silencer is currently 10mm. It should rise to around 15mm once I apply some rubber to the top of the bearers (allowing for some compression). I’m thinking this should be more than adequate to deal with any sag in the joist over time – mainly because the silencer is attached (in a decoupled way) to that joist and silencer and the joist and silencer should be moving in concert and because the LVL was selected for minimum sag given its width and the span. Am I missing anything here?

Front view - I know it looks like it touches the outer ceiling but there is 40mm gap

the props are just sitting there ready to raise the unit to attach rubber to the support beams

the bottom timber running across is just a safety measure until everything is secured

if you can see past the reflection, that gap at the bottom is ~10mm

[gullfo]

you should be ok from a sag perspective.

the thinking should be the silencer assembly can be secured to the wall as part of the isolation boundary. where you might have it not in full contact would be either the ceiling or the wall, but not necessary both unless you already have that joined hard. meaning it its effectively a single assembly and not a pair of decoupled assemblies, then joining at the silencer box is fine, and any shifting etc is as one assembly.

if they are decoupled, secure to the surface with the duct (coming through the wall or coming through the ceiling, and fill the none secured part with a layer of caulk etc so it's not necessary a hard connect to allow shifts between the two assemblies but preserving the duct side which is sealed (or should be).

[gearjunk1e]

An update and some context around the decoupling of the silencer
The CR inner silencers are now sitting on their supports

– with a layer of rubber on top of the supporting beams to dampen any vibration from turbulence.

I’m not too worried about this in the CR but thought it was worth trailing for the LR.
Also the isolated fixings are in place to make sure the silencers don’t wander..

The supply duct is all secured.

Back to work - will post an update on the CR ceiling later..

[gullfo]

ahhh. gotta love caulk. caulk is your friend. you will learn to hate caulk, but caulk will still be your friend.

[gearjunk1e]

ahhh. gotta love caulk. caulk is your friend. you will learn to hate caulk, but caulk will still be your friend.

yep...into box 6 of 24 x 600ml FC11 sausages and counting... and before than a chunk of DAP230

My relationship with caulk has reached a new level where I change the lyrics to music playing on my radio while working...while we call it sealant here, caulk rhymes much better...think Neil Young and "It's gonna take a lot of caulk"
My neighbours would think I'm crazy if they could hear me but I reckon anyone building these starts crazy and it only gets worse..

[gearjunk1e]

While we are on the topic of caulk/sealant..

Control Room "inside out ceiling"

I’m currently in the throes of installing the inside out ceiling modules – have completed 3 so far and am sharing my experiences here as I can’t find a lot of detail around how people have got comfortable with the sealing process.

The first one I installed in situ - dropping the Fyrchek sheets in from above and doing the backer rod/sealant from above. No option to do the “push up” method as the joists are not parallel in this spot as it’s where the flat ceiling changes to the rake so you can’t “push up”. I’m glad I only have to do one more of those.

The second was a “push up” module type. I have cleats across the top and a frame that holds the Fyrchek which I’m raising with my drywall lift.

(Straight out of “How to build an inside out ceiling” - viewtopic.php?f=12&t=50.) The modules are light enough for me to then raise each end by hand from where the lift stops against the joists and hold it in place with some clamped blocks before securing the frame to the ceiling joists.

For me at least, the hardest part of this is getting the right amount and even spread of sealant to get a continuous seal. I want enough sealant to seal the gaps but not too much so that it ends up all over the joists as it gets lifted into place or more critically, that it ends up creating gaps due to unevenness in the sealant resulting from the “pushing in” process.
So for the 2nd one (first of the “push up” variety), I went with a clearance of 1mm between frame/Fyrchek and joist and 2 generous beads of sealant that I applied to the joist/cleats rather than to the module itself; 1 bead in the corner where the cleat meets the joist and the other around the joist at the height of the lowest sheet of Fyrchek.

Given the small clearance and volume of sealant, I was surprised to see no “bleed” of sealant from where the top of the module squeezes up against the cleats. This means that either I got it right or that there was too little sealant. Without superman vision, it is impossible to know. While I’m 99% confident that the seal will be solid in the frychek/joist join, to improve my confidence in the seal, I then sealed the cleat/frychek join working from above.

Never again – using a caulking gun in a 200mm (8”) space is not my idea of a good time – but I already knew from the unit I had to install in situ. I also sealed everything below

On the third (the second “push up” one), I went with the same clearance between frame/Fyrchek and joist and the same 2 generous beads of sealant applied to the joist/cleats.

But for this one I added another bead on the top of the fyrchek where it would hit the cleat - only I forgot to take a pic!

While thinking about how to fix the ceiling sheets under the silencer boxes, it occurred to me that the method I’d been using so far was a little bit overcooked for the weight of the Fyrchek I’m hanging, so I reverted to a more “traditional” approach of:

1. Fixing the cleats to the joists;
2. Screwing the first sheet of Fyrchek into the cleats – leaving a 5mm gap;
3. Pushing backer rod and sealant into the gaps;
4. Fixing the second sheet with some holding screws and temporary cleats for safety;
5. Pushing backer rod and sealant into the gaps; and
6. Attaching the frame (really acting as cleats) under the second sheet

No further sealant required.

This method is do-able in my situation given the weight of the sheets I’m hanging and this way I have 100% confidence in the sealing process filling the gaps. I’m not bagging/diss-ing the push up method – it is a clever solution when you have much larger modules but the “traditional” method works in my situation and takes half the time.
It will be interesting to see whether I can still use this method in the LR where the sheets will be 5% longer and 23% heavier (16mm vs 13mm) and I’ve got the green glue thing going on as well.
Just for completeness - a pic of the insulation - its easier to lay these in smaller blocks

[gullfo]

so probably a bit late here: but when i do inside-out, i prefer to layout the full set of joists and using joist hangers + a ledger board to ensure full support, then slide the materials up on the joists and then spread them out and (assuming you have the room overhead) secure them, then the last section which is open to get the last of the materials up there can be tricky if there is no maintenance space overhead - in which case i would secure the drywall sheets into the plywood/osb, so a single slab, then slide that over onto the joists / cleats (if possible have the sheet staggered but not always possible) and the secure via toe-screwing the cleats (erm, maybe there is a better term for toe-nailing using screws... ) to lock down the final bit.
this approach is what i use when i have the overhead space and massive ceiling units (like a recent design where each section even reasonably small would be >500Kg and 4m up...)

your approach is good and should be successful...

[gearjunk1e]

Glenn
Makes sense
Much of the way I'm going about it is driven by working solo and to some degree by the steps already taken.
If I did it again I'd do it your way
Andrew

[gearjunk1e]

Hi

2 super quick (and easy, I hope) questions

1. I've been planning some manholes in my ceiling so I can get to the points where the duct joins the silencer. I've seen some designs that Glenn circulated for trap doors/manholes and I think Jennifer has incorporated an access point somewhere (for a different purpose). The question is whether it is really worth the effort - what is the likelihood of needing to get to those joins at any time in the next 20 years? (given I'm installing to AC code - and the temperature variations and pressure are waaay lower here)

2. I've yet to precisely nail down plans for my soffits but am trying to work out my audio cable runs between the rooms. It is possible that I may need to run my cables through one of the soffit wings near the floor. While I understand that the soffit baffle boards need to be thick and strongly framed, I am of the understanding that soffit wings are more akin to wall panels like Jennifer's here

- so if I need to penetrate the wing low down it should not have any real impact. Is this right? (Jennifer - sorry about stealing your photo )

Here's a super rough WIP design of the soffits - its the wing on the left that I'm referring to.

Andrew

[endorka]

No worries

I installed the trapdoor because I anticipated having to access the ventilation filter box behind it every 6 months or so to change the filter. If it was just ducting and I was confident with the joins I'd probably just have drywalled it back up again. If the drywall was multi layered or specialised in some other way that would make repairing it back to standard again difficult I might still have gone with the trapdoor though.

Cheers,
Jennifer

[gullfo]

correct - the general ducting can be installed as a permanent part hidden away, but you should have access to the maintenance points - filters, a way to perform duct cleaning every 3-4 years, fans, etc etc.