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

[gearjunk1e]

I’ll now consolidate all my posts to the construction forum. While I’m still “micro” designing, I think it’s better to be all in one place for now.
This will be a long one – I first drafted this for a September post but

• keep getting distracted by doing the work ; and
• felt that there was not much earth shattering stuff to share – just stories of painstaking discipline, moments of frustration and precision in execution

So I’ll start from where I am now:

• I’m just finishing up the dividing wall between my workshop and studio (this completes the outer wall) – using “yellow tongue” on part of the second layer, which is a flooring product used here extensively. It’s essentially particle board with a hard finish and a groove on the edge where a 12x5mm plastic insert sits to keep the joins in line. In this case, I sawed off the edges to remove the groove so that I could get a more efficient contact surface for sealant in the panel joins. I used the yellow tongue boards up to 2.4m off the floor to generate a harder surface than gyprock on the workshop side. No acoustic reason – just practicality. The surface density of this material is about 6% above the 16mm gyprock sheet I’m using on the outer wall (fyrchek) and I’ve used green glue in between the first layer of fyrchek and the yellowtongue.



Overview of the workshop side outer wall - you can see the sway bracing across the top on the LHS - this is bolted into the 250mm C section metal frame and is bolted into the top plate which in turn is nailed into the LVL frame either side of the jamb



layer 1 of outer wall - you can still see the CR door frame - LVLs right up both sides and over the top that connect eventually to the sway braces which in turn are bolted to the metal shed frame



Starting to add yellowtongue

• I’ve completed the second layer of fyrckek in the CR. To do that I’ve framed the LR-CR window space. While I haven’t done the detailed ray tracing – the window glass will start at 42% of CR room depth and finishes about 950mm off the back wall - to give me room for the rear bass traps. I would have thought it unlikely that this window position will be problematic for early reflections but if so, I might have to consider angling the window glass or more likely, employing what Stuart calls “variable acoustics”

CR shot from the LR

CR window side

CR RH wall - yet to do layer 2 around the mullion post which will be mdf (a bit harder than gyprock) - part of mdf layer is standing next to it. Inner silencers almost ready to mount

Looking to the front of the CR where the soffits will go

• The AC units are in and I’ve just to do the last 10% of the “Big Stretch” sealing of the penetrations. I had to bring forward the finishing of inner room walls on the workshop ends of the CR and LR to allow mounting of the inside end of the split units.

Front wall of LR completed to allow mini-split mounting

AC work in progress - they came 3 times for the install to allow me to do some sealing of penetrations

Front wall of CR completed to allow mini-split mounting

LR mini-split in

CR mini split in

Aside from all of this, since the last post I’ve;

• Rechecked my isolation calculations and modified the inner wall construction for the CR – now 2 layers of 13mm Fyrchek (drywall). According to my calculations, this will be more than adequate for attenuating the maximum sound generation (85dB) to target levels. Once the LR is complete, I’ll assess whether any transmission from the LR is problematic with this density setting and if so, add a further layer before treating the room. The outer wall and LR wall specs are unchanged - 2 layers of 16mm fyrchek (or equivalent) with green glue between.
• Finished off all the wall framing for both the CR and LR, aside from the LR infill framing where the ceiling joist meet the walls and the framing around the last of the column incursions.
• Started hanging the 1st layer of fyrchek on the live room (before I changed execution strategy)
• Fixed the sway bracing solution above the outer wall that houses the doors
• Finished the double jamb for the CR door
• Constructed the 4 isolation boxes for the CR. I found it harder to get a good finish stapling the duct liner so have opted for using more of those plastic discs to hold the duct liner in place.
• Got my electrician to run the power/lights cabling and Ethernet cabling into the LR and started filling the penetrations with “Big Stretch”
• Completed the frame that supports the mounting for the outer silencers for the CR and mounted those units
• Finalised the plan for audio cabling between the two rooms.

I think I've hit the attachment limit so will post some of the progress pics of work described above over the next couple of days

Next steps

I’ve changed execution plans again – I’m now aiming to get the CR operational (not as a fully fledged CR yet, but as a functioning isolated room). That will allow me to set up my AdamA7x’s and do some REW room measurements plus set up my guitars - I reckon I’ve played amplified electric guitar no more than 40 hours over the past 3 years. At the same time, I’ll continue work to complete the LR. Such an approach suits multiple purposes – allows me some moments of sanity when I can play music without having to drag all my gear out of storage and set up/pack up AND gets much of my gear out of the house – happy wife, happy life .

So next steps are to:

• Install the CR inner isolation boxes
• Install the ducting, filter and fan for the CR
• Build and hang the ceiling modules for the CR
• Hang the outer layer doors for both rooms and maybe the inner door for the CR;
• Put a temporary “fill” in the window space while I use the CR but am working on the LR; and
• Get my electrician back in for a “rough in” run of power to the CR

I will TRY and keep the updates more regular now that things are getting more interesting – I’m in awe of the posting diligence of the likes of Endorka, Starlight and Garethmetcalf, among others.

My plan says this all of the "next steps" get done by mid February, but all of my plans so far have been 50% (at least) too optimistic)

[gullfo]

if the window is a problem during mix time, pull the drapes over it

[gearjunk1e]

if the window is a problem during mix time, pull the drapes over it

Too often the simple and obvious solution gets overlooked
Thanks Glenn

[gullfo]

variable acoustics. c'mon man!

[gearjunk1e]

As promised - some shots of my last 6 months work mentioned in my detailed post #16..nothing earth shattering here but maybe some insights for others (or not!)
First up...silencers...
• The inner ones are "dual flow"
• 16mm mdf - 2 layers
• Any joins were given a good layer of glue (layer 1) or sealant (layer 2) before screwing, aside from baffles that got glue then a good bead of sealant around the edges..
• Green glue between 1st and second layer
• More sealant applied to outside joins - just for good measure

My work is not as tidy as some - saving the perfectionism for the parts that will visible (and the black sealant was the only colour available at that time - since then I've got my hands on a couple of boxes of white ) I've used every FC11 colour and found that white is the best to work with and black is the worst

Stage 1 of unit 1 underway!

my method for holding baffles in place while screwing

ready for some sealant where the baffles meet the walls/bottom

inner silencer with baffles - 1st layer.jpg (41.43 KiB) Viewed 7344 times

ready for some sealant where the baffles meet the walls/bottom

inner silencer with baffles - 1st layer.jpg (41.43 KiB) Viewed 7344 times

making the registers

had to get the duct opening as high as possible so I can avoid cutting a piece out of the top of the joist it will sit next to - to allow the duct a straight run into the unit

Laying the bottom liner

Ready for the top liner and layer #1 top

I got my hand up in the registers and duct void and screwed in the duct liner to the inner layer top using those plastic discs - this held the duct liner in place when I lifted the top out to do the rest of the fixings

I had a brace inside until I drilled screws for the top

ready to start unit 2!

Fits perfectly - after some mods!

CR exhaust side outer silencer in place - lots of juggling using the panel lift and acrow props

Again a little bit of filing to fit

plenty of FC11 in there! Needs a tidy up before connecting the flex-duct

[gullfo]

nicely done! i use similar designs a lot to get more expansion and more symmetry. both on supply and return units.

[gearjunk1e]

More shots of late 2023 work

Penetrations for AC, Elec, ethernet
AC sealing - using "Big Stretch". I cut some access holes from the outside so I could get in and under the pipes plus the installer left the front covers off the units off for a week or 2 so I could get at the holes from the inside also (3rd pic). Also had to make a couple of tools from left over metal strapping to apply sealant under the pipe bundle (sort of a "j" shape) and tried using some pipe on the end of the nozzle as well...mixed results with the latter .

Elec/ethernet penetrations

One entry point per room for elec - cables can then run in between the joists to where it needs to drop down (or feed the lights) - that area between the joists will be an inside out ceiling on the top and then filled with insulation - never seen!

same drill here as with elec

ethernet access.jpg (40.71 KiB) Viewed 7271 times

same drill here as with elec

ethernet access.jpg (40.71 KiB) Viewed 7271 times

outside entry has been sealed as I need to put the sway brace in front and access would be harder once that was in place - plenty of goop in the pipe, around the pipe and then a regular anthill of sealant just to be sure

[gearjunk1e]

...and more
this time, mostly framing - some selected shots

enough framing to get the front wall up for the AC install

then a bit of fun getting the CR middle wall with window frame in - largely because I wanted to keep the floor open to walk through as long as possible

only a few more studs to go in over the window opening - that was the easy part!

Finally got to the point of having to fill in below the frame - by then I'd completed the first layer of gyprock the framing for the LR wall on the other side - you can just see the upright on the far side of the window opening

Going back a couple of steps - the CR door framing - you can see how the LVL's form the outer part of the frame and attach to the top plate - outside, the sway bracing is screwed into the top plate and attached to the 250mm x 75mm metal framing of the shed. (The LVL lost its red colouring on one side as I had to shave 2mm off the width so it lined up with my 90mm wide studs).

Here's a shot of the sway bracing in situ and one of the construction thereof

(There is a long story why I could use the panel lift to hang this sheet)

I have these mullion columns that are attached to and form part of the outer shell (this pic is from the LR). They push about 230mm into the space from the rest of the outer wall. Some to'ing and fro'ing with Glenn back in late 2022 ended up with me framing around these - while its been a bit of work, I will gain about 6" of room width in the LR (over 6.9m) and the same width gain in the CR. Useful in the LR but worth its weight in gold in the CR

One more catchup post to come, then I can share the joys of hanging the internal silencers...

[gullfo]

nice workpersonship! glad the idea to frame around worked to gain that space.

[gearjunk1e]

nice workpersonship! glad the idea to frame around worked to gain that space.

Thanks! Yeah - got better at the design and execution as I did them - again through experience

nearly at the end of the catch up posts - walls this time - the door jamb I will do separately

Looking from the other side of the CR through to the LR in the line where the window will go - this is where I stopped the LR to focus on the CR completion (a pile of mdf in the shot...just waiting to grow into silencers!)

I had to cut insulation in strips on the walls where both walls where both walls were normal ie not inside out

Ceiling beams up and insulation underway - while I did prepare the door side wall for the AC unit to be installed I only did layer 1 and enough of the rest where it was needed - that way I could keep to the corner protocols for hanging/sealing

infill framing between ceiling joists and insulation up to the outer ceiling

Looking towards the front of the room where the soffit will go - little bit of packing - not quite sure how I stuffed it up but I do know it takes at least twice as long to fix it than doing it properly the first time!

I wish I'd read Jennifer's post on doing cardboard cut outs to test angles before I did this - the rake will be great for the room but angles are very time consuming and the up and down with the measuring and adjusting gets tiring

checking cut outs.jpg (47.31 KiB) Viewed 7201 times

I wish I'd read Jennifer's post on doing cardboard cut outs to test angles before I did this - the rake will be great for the room but angles are very time consuming and the up and down with the measuring and adjusting gets tiring

checking cut outs.jpg (47.31 KiB) Viewed 7201 times

one more post to come on the door jamb/frame

[gearjunk1e]

....door jamb/frame
I followed the same path on this jamb as the LR one - its a double arrangement per Stuart's "site built door for high isolation" but I was way quicker this time having learned the ropes on the first
It's the John Brandt design - rubber seal between the 2 jambs and rubber seals on angle iron that can be removed in need. Once I've installed the doors I'll see if I need more than just the seals on the stops

You can just see the rubber in the gap - it was 100mm wide and that tape sticks like nothing else...I used the table saw before bracing the two jambs together to rebate enough of the back of sides of the frames so that the rubber would sit flush with the rest of the frame - to ease install issues and make it "easier" to get a good coverage of sealant between the jamb and frame

I popped some pieces of wire under the frame to help guide it in and help keep the sealant fairly even sealant fairly even

I had to include some shots of testing the jamb in the frame for gaps, plumb and square - I hesitate to think how much time got eaten doing this but am hoping the investment will pay off when I hang the doors and do the seals

Here you can see the little rebates I routed in to the edges of the frame members that sit against the jamb - while I had plenty of sealant on the frame when I installed - having these 8mm rebates meant I could be confident of getting a consistent layer of sealant between the jamb and frame even if what I'd put on the frame ended up being a bit inconsistent from the process of sliding the jamb in

Once I'd got the jamb in place I then re-inforced it with some 70x35 timber you can see in the attached - these attach to the jamb, and hard up against the frame including the LVLs that run up to the top plate and the sway brace. To do this I stopped the gyprock/yellowtongue 70mm short of the jamb position - again I ran a rebate along the edge to apply another layer of sealant. This arrangement will give me a very solid base for the hinge screws.

...and finally a shot of the mock up of the door seals - I cut the slots in the jamb before hanging it

OK that's a wrap on the history - I've just got the 2nd inner silencer in and will post soon on the "adventure" it ending up becoming

[gullfo]

very nicely documented! creating the jamb assembly for both sides as a temporary single unit is essential for getting precision alignment while installing it and avoiding future bridging (if you're trying to avoid that). nicely done!

[gearjunk1e]

Bridging was a concern. I've never been able to reconcile the maxim that no part of the outer and inner walls should touch in the slightest with having a single frame/jamb for doors and windows. It would have been sooooo much easier to do a single jamb but for me, I'd want to see two things first:
1. solid empirical evidence supporting it AND
2. a satisfactory explanation why you can bridge doors and windows but nothing else.

...and thanks for the positive feedback . It's hard staying "up" on a long journey when working on your own

[gearjunk1e]

Raising the inner silencer boxes
I’d been dreading this for a while – I knew the hanging of the internal silencers would be fun! I’d looked at a few material handling lifts I could hire for the job locally but complications with access, availability, free floor space and with the supply unit having to be lifted then pushed in to get around the AC, meant that the best tools ended up being a combination of;
1. My Drywall lift and
2. Acrow props
...together with some straps for safety and some clamps at certain points.

I started with the supply unit – I’d left the very top piece off which reduced the weight of the unit to 53kg (lift capacity = 68kg). I’d worked out that I could add this in situ if I predrilled the screw holes and only raised it initially so that the top aligned with the top of the joists rather than sitting about 150mm above them as it would be when in place. I had also worked out that I would need to remove the rail that would hold the bearers the unit would sit on, so as to create enough room to raise the unit into the space. I had also knew that I needed to install the spigot for the flex-duct attachment before it went up as the only thing I could realistically do about ducting while in situ was to attach the duct to the collar.

I wanted to assess how much access I'd have before I raised the unit - popped in a couple of bearers and some board to give me a line on space/access

Easy - raise the box above the AC unit, push it in and raise again

The easy end attached (mastic, tape and o-rings) but all dressed up and nowhere to go ...yet

Testing the lifting (or so I thought)

What I missed however, was that in adding the spigot before raising the unit meant that the unit, including the duct collar protrusion was now 15mm wider than the space it had to slide into. After this discovery, an hour or so of angst followed, before it occurred to me that I could slide it into the space if I cut out a small section of the 3rd layer of gyprock where the spigot would run up against the wall and cut 10mm off the collar – still leaving the requisite 51mm for the flex duct join. The cut out would be replaced after the unit was installed.

Took 3rd layer off in the centre where the spigot would run

10mm off with angle grinder - stuffed an old towel in the duct space to avoid any filings entering in

Happiness restored, I set about building a frame for the box to sit on – this was clamped to the drywall lift and designed to compensate for the fact that the box needed to sit on the edge of the drywall “forks” which causes them to slope down.

crane to drywall lift

However, the weight of the box generated more slope than I expected so I had trouble getting the silencer over the AC without fouling on the joists above. After much fluffing around, I finally got the box over the AC unit by pulling down a strap I put around the drywall “forks” at the opposite end to where the box was sitting – to bring it back to “levelish” - while my wife pushed the drywall lift in.

Pulling down on the strap levelled the unit enough to get through the AC-joist gap

From then it was just a matter of inching up the acrow props and the drywall lift before I went down to the hardware store and got another prop to replace the drywall lift for this last part.

Success!!

Just acrow props from here

5mm clearance

Then it was just about slowly inching up each prop until I had the box high enough for the lid to go on.
Then the lid went on – starting the screws by hand until I could squeeze the driver in to the space.

Bit of a struggle getting enough on in the right places with limited space and having to bend around the AC - there is a lot more sealant on there than shows in the pic

Green glue on and lid screwed down - time to raise the unit again!

14 CR sup sil top lid on.jpg (41.64 KiB) Viewed 7086 times

Green glue on and lid screwed down - time to raise the unit again!

14 CR sup sil top lid on.jpg (41.64 KiB) Viewed 7086 times

I'll continue in another post...

[gullfo]

possibly late here - however - presuming you'll have a soffit around the ceiling for additional absorption, lighting, wiring trays or conduits, etc etc, using a ledger board under the edge of the assembly can assist in positioning and retaining. same way you'd do a cabinet where you ultimately will hide the "magic".

hopefully your wife was compensated for the labor @ the prevailing labor wages rate...