Soup Studio, UK, design and construction

TheFrenchVoice wrote:

Thanks for the clarification Brien, I stand corrected. And just so Giles isn't confused further, let's confirm that the solution I offered is the correct one, if you're so inclined.

This structure has three brick walls as the perimeter side walls, and, as we are now finding out, a staggered stud wall on the fourth wall boundary. I do not know if I would tear down an existing staggered stud wall until it could be determined that tearing it down, massing it up so that it matches the existing brick (assuming that it does not match the existing brick in the current configuration) is the way to go. It may be that adding mass directly to the existing staggered stud wall, might produce better results with less hassle. But, the ceiling may well be the determining factor in respect to how does it get framed into the design so that you develop one air space with the whole room-in-room build.

Agree with Brien: 3 brick walls plus a staggered stud wall already has plenty of mass, and might well be dong a good job of isolating, even though it is possibly acting as a 5-leaf system. But unless the ceiling is also done with three leaves of brick and a staggered-joist thingy, then tat is going to be the weak point. The other issue is flanking paths: Is there anything that connects through or around those 3 leaves of brick and staggered stud wall, or are they fully decoupled? That's the question I would be looking at. And then, of course, comes the issue of doors and windows... I've never seen a door made of three brick walls and staggered studs! :) - Stuart -

Hang on now...there is no 5 leaf...there is only potential if the design doesn't get adjusted. The existing brick exterior with an interior framed assembly, only a mass-air-mass...that's good. The one wall that is staggered stud, tat needs some attention..

Wow, guys, thanks! Sorry for the delay in replying, I thought I got an email every time I got a reply, turns out I don't.

xSpace wrote:

The other issue is flanking paths: Is there anything that connects through or around those 3 leaves of brick and staggered stud wall, or are they fully decoupled? That's the question I would be looking at.

Those three walls are fully decoupled, which is possibly why I merrily continued the design of this decoupled wall along the 4th side without considering that this would create a 3-leaf system on this wall.

xSpace wrote:

It may be that adding mass directly to the existing staggered stud wall, might produce better results with less hassle.

How would you suggest doing this? Further layers of studwall, attached with green glue? Thanks guys!

How would you suggest doing this? Further layers of studwall, attached with green glue?

You cannot "attach" anything with Green Glue! :shock: It is NOT glue! It is not meant to be an adhesive, and cannot be used to attach one layer of drywall to another. - Stuart -

Giles, you said in an earlier post:

The existing internal wall, separating my unit from the next unit in the warehouse, is a single timber frame, filled with rockwool, with staggered double-leaf studwall on either side. My original plan was to construct a double-wall inside this, with the outer frame being attached to this existing wall.

So there's no brick wall or anything else, is that right? Re. GG: the second layer of plasterboard (with the GG on it) is simply screwed to the metal or wood studs that support the first layer of plasterboard. Tip: fix the first layer with a screw each corner and that's it. The screws fixing the second layer will also fix the first layer to the studs, less chance of running into the first-layer screws, and more screws to fix the second layer.

Tip: fix the first layer with a screw each corner and that's it. The screws fixing the second layer will also fix the first layer to the studs, less chance of running into the first-layer screws, and more screws to fix the second layer.

That's one way of doing it. Another way is to split the screw schedule between the two layers. For example, if the screw schedule calls for screws every 8 inches, then put them every 16" on the first layer starting at the corners, and also every 16" on the second layer but starting 8" from the corners. Also, the screws on the first layer should be the normal length, and the screws for the second layer should be the normal length plus 5/8", to ensure penetration to the correct depth. - Stuart -

Soundman2020 wrote:

So there's no brick wall or anything else, is that right?

That's correct. I've mocked this corner up in sketchup to make things clearer. The studwall on plasterboard on the left, which divides our unit from the adjacent unit in front of the concrete beam and pillar, is already built. The exterior brick wall borders us on the other three sides, and the double frame studwall is our plan to build an independently framed room within a room for the live room. As Brien notes: 2

xSpace wrote:

The existing brick exterior with an interior framed assembly, only a mass-air-mass...that's good. The one wall that is staggered stud, tat needs some attention..

So from all of you who have been kind enough to make suggestions I have the following options. 1. Pierre suggests removing the inner layer of plasterboard and creating a MSM system:

TheFrenchVoice wrote:

for you to have a 2 leaf ie. MSM, you do: plasterboard (on the other side of the studs) - GG - bits of plasterboard fitted snuggly in the studs 'cavities' maintained against 1st layer of plasterborad with clits fixed on the sides of the studs - insulation (not too dense, just on the roll is fine, as thick as posssible) empty space (min. 10cm) - insulation - metal or wood studs - plasterboard - GG - plasterboard. If you want a void of 50cm between each M and that you install insulation 15cm thick then you have a void between insulations of 20cm

2. Brien suggested

xSpace wrote:

It may be that adding mass directly to the existing staggered stud wall, might produce better results with less hassle. But, the ceiling may well be the determining factor in respect to how does it get framed into the design so that you develop one air space with the whole room-in-room build.

As you can see from the diagram, the location of the concrete beam and pillar makes this quite complicated. If I add mass directly to the plasterboard as it is, there is no room to do this behind the concrete pillar. Option 1 would allow me to build the inner frame around the pillar, so the pillar does not intrude into the room-within-a-room. I don't know how the pillar would be dealt with if I took this option. 3. I am considering a third option of building an interior studwall with layers of plasterboard straight up the wall on the inside of the concrete beam/pillar. I think, from my understanding of some of the posts here, that although this would create a MSMSM system, the inner space would be around 50cm and hopefully enough to negate the triple leaf effect. I could well have misunderstood this, though, so I'd be very happy to be corrected. 4. As I may have mentioned before, it has been suggested to me that I build a brick wall. If this was built flush with the plasterboard that is in place would I negate the triple leaf effect? This is the option I understand the least! Any comments and advice on these 3 options very welcome. Cheers guys

The exterior brick wall borders us on the other three sides, and the double frame studwall is our plan to build an independently framed room within a room for the live room.

Why do you need a double-framed wall to put on just the ONE additional leaf that you need? :shock: You already have the brick wall: that is your outer leaf. So you ONLY need ONE additional leaf, the inner leaf. That needs only a SINGLE stud frame, with one or more layers of drywall on only ONE side of it. That's all you need there for the brick wall section: No double-framing required! - Stuart -

I agree with Stuart on that. Here is what I would like to see, and it will require some more work on your part thehaircut. Can you draw up a Sketch that shows exactly how you would do the ceiling framing with your existing configuration? I think we may be able to understand better how the existing staggered stud wall fits into the design and weather removing the interior side of this staggered stud wall would work better or what needs to be done to accommodate this.

Stuart - thank you so much for that point! That is incredibly obvious now that I think of it, but I didn't, and you've just saved me a LOT of wasted time and money. Would you recommend using wall hangers, such as (http://www.mason-uk.co.uk/basket.asp?pid=415) to attach the studwall to the brickwork? Brien - thank you for asking me to clarify this. Here is a side view of the wall in question as it currently exists. Here is how our new ceiling framing would be constructed if we went with option 1 as suggested by Pierre (removing the internal plasterboard, and building a new stud wall to create a MSM system) Does this seem sensible? For the other options kindly suggested, I am not sure how the ceiling framing would work. For option 2, as Brien suggested, the only way I can see it working is to remove a section of the inner plasterboard at the top of the wall in order for the ceiling frame to connect to it and preserve the integrity of the room within a room. All comments and thoughts gratefully received.

Does this seem sensible?

Yes, that will work. The only thing you'd need to be careful with is the size of the air gap between the concrete ceiling and the new inner-leaf ceiling drywall. That gap needs to be as large as possible, absolute minimum 4" (10 cm), ideally as large as the gap in the walls. You also need to dimension those joists to safely support that load over that span. In fact, if your joists are dimensioned correctly, I'm sure your air gap will be big enough. :) And of course, you still need to put plenty of insulation in the air gap all around the room (walls and ceiling). Looks like you have a plan! - Stuart -

Thanks Stuart I think I'll go for this one. Would you recommend using wall hangers, such as (http://www.mason-uk.co.uk/basket.asp?pid=415) to attach the studwall to the brickwork, or would they make the gap too narrow?

Personally, I don't think you need those. If you frame the walls and ceiling correctly then you'll have plenty of isolation and structural strength. Adding more devices like that just adds cost.

That's really good news! Does that mean my studwall should be flush with the brickwork or should there still be a 10cm gap?

That's really good news! Does that mean my studwall should be flush with the brickwork or should there still be a 10cm gap?

The first rule is: no contact! Meaning that the stud frame must NOT touch the brickwork at any point. So you need a gap. The gap you need between the wall and the frame depends on how much isolation you need, and the type of music you'll be mixing in there, but the general rule is: the more the merrier. Big gap is better than small gap, since it brings down the MSM resonant frequency. But don't confuse the wall-to-frame gap with the actual "between leaf" gap. The MSM resonance depends on the distance between the LEAVES on either side of the wall, not the distance that the frame is away from the wall. Assuming 2x4 framing, a one inch physical gap (2.5 cm) between the wall and the framing will give you a 4 1/2" (11.5 cm) air gap, but if you were using 2x6 framing with a 1" gap to the bricks, the air gap would be 6 1/2" inches (16.5 cm). It's the air gap that matters, not the framing-to-wall gap. So how big does the air gap have to be? Depends, like I said above, on how loud you are, how quiet you need to be, and the type of music you mix. Louder means more air gap. Music with lots of low frequency energy means bigger air gap. etc. - Stuart -

Right, yes, so I'm going to put in a 10cm gap between the brickwork and the studwall which will give a total air gap of 20cm. A rep for Mason industries called me up about a quote for their ceiling hangers and recommended that I would only need a few wall hangers for stability, which in the light of what you've said sounds like rep speak for "They're not really necessary"! He did suggest to me an interesting design for the floor which I've not heard of before, and I'd be very interested to know people's thoughts. I explained my plan for a decoupled floor system that Rod Gervais describes on Figure 10.16 (page 270) - i.e rigid fibreglass insulation covered with double layers of plywood and a flooring on top. He pointed out two problems with this - the expense of rigid fibreglass insulation and it's tendency to collapse if wet. He suggested the following alternative: Rubber isolators (manufactured by Mason Industries, naturally) with a 600mm/2ft center (Is the correct term to suggest 600mm between isolators?) supporting: a double layer of 12mm plywood, with staggered seams supporting: paving slabs, with 2"/50mm gaps between filled with grout supporting: another layer of plywood supporting: a floor surface. He said this option would be cheaper, provide greater isolation, and be strong enough to support the walls, which my previous choice would not. Does anyone have any experience with this technique? All the best, Giles

sounds like rep speak for "They're not really necessary"!

:!: :lol: :shot: Yup!

He pointed out two problems with this - the expense of rigid fibreglass insulation and it's tendency to collapse if wet.

Why would it get wet? If your floor is built correctly, there's no way it should get wet. The other issue is: did he give you any information of semi-rigid fiberglass "collapsing" if wet? Maybe you could call or write to Owens Corning and ask them what happens if 703 gets wet. But anyway, you seem to be intent on floating your floor. Why do you need to do that? You already HAVE a concrete floor for your studio, so why would you want to float something else on top of that? That doesn't really make sense, especially considering the amount of height you would lose. I'm not sure if you have read these two links, but you REALLY should, before you decide on how to do that: viewtopic.php?f=2&t=8173 http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf - Stuart -

Intent? Not at all! This guy was pretty convincing on the phone but I guess that's his job. Thanks for the link to that post, I'd read it ages ago, but I guess I forgot it a little. I knew I didn't need a floating floor, it just hadn't occurred to me in my previous post that I was describing one! I notice in some of John's designs that he refers to in that post he floats the walls, not the floor, on neoprene pads. Do you think this is something I should consider?

Soundman2020 wrote:

Does this seem sensible?

Yes, that will work. You also need to dimension those joists to safely support that load over that span. In fact, if your joists are dimensioned correctly, I'm sure your air gap will be big enough. :)

Doesn't matter. If he is using a decoupling device then that is what it is. Fact is, you cannot build a 45 degree angle type framing that is in want to support a ceiling like is being suggested that will have any type of rigidity. The angles will be the weakest point and using a larger size material will not correct that flaw. What >could< be done is to have a truss built that incorporates this 45 degree angle into the design so as to help distribute the load.

Hi Mr Cut, From my experience, I "floated" the Control room walls on 50mm Expansion Joint Foam and didn't "float" the drum room. The difference is very noticable. The control room is much quieter. Oh if I could travel back in time......

That's interesting Lilith, did you still use dynabolts or some kind of mechanical tie-downs on the sole plates?

xSpace wrote:

What >could< be done is to have a truss built that incorporates this 45 degree angle into the design so as to help distribute the load

Thanks Brien. I think once again my diagram was letting my down. The previous diagram was a cross-section through the middle of the wall. I intend to use a truss, as roughly sketched below, to support this structure. Was this the sort of thing you mean?

lilith_envy wrote:

From my experience, I "floated" the Control room walls on 50mm Expansion Joint Foam and didn't "float" the drum room. The difference is very noticable. The control room is much quieter. Oh if I could travel back in time......

That certainly is very interesting! Can I ask three questions - what surface were your walls "floated" above, what company manufactured the foam you used, and did the foam cover you entire bottom of the wall or was it just in sections or strips? Thanks so much for all your contributions, everybody.

floated anything requires a fully decoupled connection, walls included.

Hi, Yes each wall section had 2 x dyna bolts. You can use rubber gym mats, I just used expansion joint foam. Off the shelf...not sure of the brand. If this makes no sense, it could be down to the two different brands of wool? But the difference is quite significant. The foam can also help with levelling little differences in cement level. Oh and yes I built on a slab. lil