Soundman2020 - Studio Design Forum

Hello all, starting a new construction thread, since, well, the construction has started (and progressed!). Here is the design thread that I started with: viewtopic.php?f=5&t=848

Some pics to tell the story so far.

Here is what I started with:


Gutted:


1.5" rigid insulation on the block walls. Walls were caulked (any cracks in the mortar), then the XPS glued to the walls. The rim joist space above the block wall was sprayed with foam to create a continuous moisture barrier and thermal break:


Loos hanging 1" pink fluffy against the XPS rigid (this is the air gap ... 1" is very small, but it's better than nothing!) And the block wall has a lot of mass. On the floor is the first build "inside-out" wall panel


Inside-out wall panels going up. These were HEAVY ... around 500 lbs each 12' section. A lot of caulking used to ensure they are sealed to each other on the backside


Detail of the room in room. Ignore the random toilet ... doing a bathroom remodel at the same time!


Initial sound test with no drywall on the other 2 wall, and no ceiling (basically worst case). 115db in the room. 89db on the couch above.


Working on HVAC ducting. The Y is to tie in a feed from the HRV. Main house HVAC provides heat (if needed) and A/C. Motorized dampers can close off the house HVAC pipes, so only the dedicated HRV is active


Silencer box. Best effort here with what I have to work with. It's only on the inner leaf (decoupled from the joists). Flex duct rest of the way to the main house HVAC


1st drywall layer going up. Pink fluffy filling the joist space


Tools of our trade!


Ceiling detail from outside the room


Clay sheets for the electrical boxes. Was going to do surface mount, but I think this will be sufficient for my needs. I'll double up the clay to make a good and heavy seal.


Here we are today. All the drywall is up and mudded. Electrical is in place. Ready for more caulking, then paint and treatment!

Wow! You've been busy. Looks great so far. Lots of attention to detail. Question about your silencer boxes. Are they not attached to the joists that they're sitting in? It looks like they're sitting on those straps. Or are they attached somehow (that I can't see), and the straps are a secondary support system?

Silencer box. Best effort here with what I have to work with. It's only on the inner leaf (decoupled from the joists).

Why not use the joists? As long as the silencer is not coupled to the OUTER leaf you're fine. You'll have much better support/weight distribution.

The silencer boxes are not touching the joists or the floor above. They are jammed in the joist space with 1" rigid compressed to around 1/2" ... so a friction fit (they mostly stay up without any support actually ... they're not that massive). The straps then keep them in place. Straps are rated for 350 lbs each, so I'm not worried about them failing

SoWhat wrote:Why not use the joists? As long as the silencer is not coupled to the OUTER leaf you're fine. You'll have much better support/weight distribution.

Well, if they were mounted to the joists, that WOULD be the outer leaf. The joists and the floor above is the outer leaf ... unless I misunderstood something?? In any case, it's all sealed up now... I did have a variation of this design posed on John Sayer's, with the decoupled box, and it seems well received.

Greetings ScotcH,

Sorry, I thought you had a room-in-a-room design. I was confused (nothing new there).

350 lb weight rating? Nice.

All the best,

Paul

SoWhat wrote:Source of the post Greetings ScotcH,

Sorry, I thought you had a room-in-a-room design. I was confused (nothing new there).

350 lb weight rating? Nice.

All the best,

Paul

I do have a semi-room-in-room. The inner walls are decoupled from the outer walls. And the ceiling (drywall) is decoupled from ceiling joists with the resiliant clips and hat channel. So the drywall is the inner leaf, and the joists and floor is the outer leaf. It's at least decoupled by the rubber clips. Again, best effort with the space I had to work with.

Here is what the design cross-section looks like (pretty close to reality):

Hi
This might be a stupid question, but I'm just checking that your plasterboard ceiling is only connected to the resilient mounts and not to the tops of the inner leaf walls? I'm guessing you'll be caulking that gap. It's hard to see from the diagram!!

Cheers
Gareth

garethmetcalf wrote:Source of the post Hi
This might be a stupid question, but I'm just checking that your plasterboard ceiling is only connected to the resilient mounts and not to the tops of the inner leaf walls? I'm guessing you'll be caulking that gap. It's hard to see from the diagram!!

Cheers
Gareth

Not a stupid question at all. Here is a detail view of the cross section at the wall/ceiling intersection. There are screws going through the wall top plate, the 2 layers of ceiling drywall, and into the hat channel. And of course, it's all assembled with LOTS of acoustic sealant black goo of death, and silicone at the corners.

Interesting. I thought I’d seen on other builds that the ceiling, when mounted on a resilient channel, isn’t connected to the inner leaf walls like yours, only caulked at the intersection.

It’ll be good to hear what results you get when you’re complete enough to do a sound level test.

Cheers
Gareth

Yeah, like I said ... it's a semi-room in room The way I look at it, the walls and ceiling are essentially the inner room leaves, with the resilient clips being the only coupling to the outer structure. Certainly not as efficient as a true room in room with separate framing for the ceiling, but I'm fairly confident it will serve my needs. As you say, the real test will be with a measurement! Flooring going in later this week, then maybe this weekend I'll get to the inner door. At that point, I'll do another test, to see where I'm at.

By the way, unless I read it wrong, in Rod's book, the ceiling drywall is definitely in contact with the wall drywall. Certainly there is backer rod and caulking at the joints (and I have that as well), but there is no mention of isolating the ceiling from the walls when using resilient mounting. Do you have a link or reference? Just curious to see that done.

My apologies. I hadn't read that bit of Rod's book before and I've just seen that you're quite right - a semi-isolated structure.

I'll see if I can find any of those builds that my memory said I'd read and link them.

Gareth

Ready for flooring and wall fabric this weekend! Sounds so much more dead now already ... except for the obvious flutter echoes from floor/ceiling.

That is rapid progress, Scott. Well done!

Floor is done ... fabric on walls is done. Starting work on the corner superchunks, then ceiling clouds and broadband panels for the opposite walls next!



Btw, my name is Arek ... ScotcH is just a silly forum name I use everywhere