Starting to plan my studio

[mattr]

Realistically this is probably around 2 years away from construction, but there's no harm in having it planned Basically we're planning to convert an existing farm outbuilding into a large garage with attached studio and office space. The footprint of the building is roughly 45' by 21' and it will be converted into a two-storey building (though the upstairs will be partly 'up in the loft').

I've already roughly planned out the layout. Its going to be a simple live room + control room layout (no isolation booths). As my plans go at the moment the live room will end up being 4m x 5.5m (a good ratio I believe), which takes into a account a fairly thick wall construction.

The only quirky thing is that (due to space constraints) the control room will be above the live room, and we'll have to rely on some wall-mounted flat panels and cameras for a video interlink Sounds crazy but it wouldn't actually be that fancy or expensive; it would probably be cheaper than a good soundproofed window anyway!

I'll try and get some Sketchup drawings knocked together, but I think I'm sorted with the layout.

My question lies with the construction and soundproofing - I've read a lot of stuff but I'd like to check that I'm thinking along the right lines...

Due to various reasons, the brick outside walls of the building will be a purely cosmetic shell. The actual building will be a metal girder and breeze-block construction inside the brick wall. This means that - before actually constructing the live room - there are two walls with a small air gap between them separating inside from outside. I'm not actually looking to isolate from outside as we have no neighbours anyway, but its probably worth mentioning. This will be the case for 3 of the 4 walls of the live room. Can I use this to my advantage in any way? I suspect not, but its just a thought!

Anyway, so I'll end up with an empty box - cement floor and breeze block walls in which to construct the live room.

Within this space I plan to construct a stud wall with a small gap between the two walls (how big should this gap be?), and fill it with some form of fibreglass or rockwool insulation. The stud wall will be fixed to the outer wall with some of those isolating brackets. It will then be covered with drywall / plasterboard.

This may sound silly, but I've read that its good to cover both sides of the stud frame with drywall - how do you get the drywall on the outside of the stud frame?

Is there much point in trying to float the floor? I'd like to keep the costs down and don't see if it would gain me many benefits.

Doors? I'm planning on having two with an air gap (whatever gap results from the thickness of the wall construction). I can't afford any kind of fancy lead-lined doors and frames but I'm hoping someone might have some suggestions on how to get some good isolation from them!

Lastly is the ceiling, which I'm guessing is important as the live room will be above. Should this just be the same construction as the walls and isolated from the above floor joists?



Quite a few questions hidden in there!
Any guidance would be appreciated. Thanks.

 

[RICK FITZPATRICK]

Can you post a plan here? It helps visualize what you are talking about. And maybe a few section drawings. For instance...this is kind of vague.

The only quirky thing is that (due to space constraints) the control room will be above the live room, and we'll have to rely on some wall-mounted flat panels and cameras for a video interlink

So you're planning on a control room directly above the live room?

or...

Sounds crazy but it wouldn't actually be that fancy or expensive; it would probably be cheaper than a good soundproofed window anyway!

ah, that might be a misnomer. To isolate the live room ceiling from the control room floor may be much more expensive than a couple of panes of thick glass.

Not to mention..IF..the control room walls are simply a vertical extention of the live room walls..how are you planning on isolating them? And what about the stairway..is that going to be a soundlock design? Lots of things to consider. Of course, you have two years to plan it so it shouldn't be a problem. Best to solve all the problems prior to building...after the fact solutions for iso construction can be REALLY expensive, if not impossible in some cases.

My question lies with the construction and soundproofing - I've read a lot of stuff but I'd like to check that I'm thinking along the right lines...

Due to various reasons, the brick outside walls of the building will be a purely cosmetic shell. The actual building will be a metal girder and breeze-block construction inside the brick wall. This means that - before actually constructing the live room - there are two walls with a small air gap between them separating inside from outside. I'm not actually looking to isolate from outside as we have no neighbours anyway, but its probably worth mentioning. This will be the case for 3 of the 4 walls of the live room. Can I use this to my advantage in any way? I suspect not, but its just a thought!

By "breezeblock", do you mean concrete blocks with voids on the interior?
If so, to prevent a THREE LEAF assembly from occurring, you should fill these voids with sand and top the wall off with concrete..if I understand your description correctly. This will create a two leaf(mass-air-mass) wall which is preferable to a three leaf assembly...although, with no environmental noise to penetrate the shell, or neighbors to bother, it may not matter. Although, I believe brick walls must have some kind of "sway" brackets tied to the block structure. And depending on local codes and and the location, you might be required to apply a layer of rigid foam insullation. Before you start detailing the various wall assemblys, I'd consult with your local BID(Building Inspection Department).

Not to mention the footing/slab connections. Or, seperating HVAC supply and return duct paths to each of the rooms to prevent flanking pathways for sound. Building a control room directly above a studio creates many pathways for structural transmission and require a thorough analysis of the planned assemblys.

Anyway, so I'll end up with an empty box - cement floor and breeze block walls in which to construct the live room.
Within this space I plan to construct a stud wall with a small gap between the two walls (how big should this gap be?), and fill it with some form of fibreglass or rockwool insulation.

Why? You alread have an exterior wall with two massive leafs and an airgap. Why not simply apply furring strips and drywall. Insulation will probably be in the airgap between the brick and block, although not necessarily so. Depends on how ultimately BID requires the assembly to be built.

This may sound silly, but I've read that its good to cover both sides of the stud frame with drywall - how do you get the drywall on the outside of the stud frame?

Not silly, but you don't need a stud wall assembly. Especially one with a leaf of mass on each side of the airgap.
And besides, this would create ANOTHER AIRGAP. Which in reality will occur when you apply furring strips/drywall as well. In this case, I'd apply the rigid foam insualation between the furring strips. OR...apply the brick directly to the block.
Generally speaking, the whole decision "hiarchy" USUALLY depends on your TRANSMISSION LOSS(TL) target, as each type of assembly will have a TL RATING. However, given you have no external noise/interior noise transmission problem in the first place..it hardly matters...especially with a massive outerwall as planned. In this context, $ is probably what matters.

Oh, to answer you actual question. This depends. If your building a NEW stud wall parallel and adjacent to an existing assembly, the existing assembly becomes a leaf(which in itself may be more than one leaf, which depending on the TL target, may require additional techniques to eliminate another leaf/airgap). In this scenario, you DON"T need a layer of drywall on the OUTSIDE face..which in reality is in the AIRGAP On interior partitions, yes, you need a layer of mass on each face of the studs. UNLESS, you are building a DOUBLE WALL partition..which means you only need drywall on the EXTERIOR face of each stud wall assembly, Thereby creating ONE airgap between the leafs.
However, there ARE instances where you need to beef up the mass on an exterior leaf of an existing wall. In this case, PRIOR to sheithing the interior face, you would ADD a layer or two of drywall to the existing leaf, BETWEEN the studs, IN THE STUD CAVITY. No need to do this in your scenario.

Is there much point in trying to float the floor?

Not in the live room, but PROBABLY in the control room, since it is directly above. This may possibly be done in the framing stage, but not necessarily so. It depends on the detailing of the framining assemblys and other factors, such as how the floor membrane framing is tied to the exterior block walls etc. This would really require a thorough analysis of your budget vs available techniques vs code vs technical skills and a few other things. This is where TOTAL PLANNING shines. And quite frankly, this type of construction will require a permit, which means BID will scrutinize your plans for code compliance, which THEN you may be requied to change at thier discretion. And believe me, depending on where you live, this can be a real nightmare. Even for small projects.

As to actually floating a floor. On a second story control room..yes, but I would probably beef up the subflooring mass, and then put a layer of KIP on it. However, your wall assembly "decoupling may negate any attempt at floating a floor between walls. This is also where TOTAL PLANNING SHINES!

I don't have time to address your other concerns, and frankly, they are the least of your problems. My best advice..get a PRO architect/engineer/
planner/acoustician to address your project. Yours is NOT easy nor for the novice or faint of heart..IF you want to succeed.

One more thing...this really has to do with the type music you are planning on transpiring in the live room. No need to build iso construction aimed at Marshal amps on 10 if you are only recording a flute.

fitZ




fitZ

 

[mattr]

Hey, thanks for the detailed reply! You certainly know your stuff
I'll take another look at it in light of what you've said.

Just a few thoughts...

Basically the control room has to be above the live room in order to maintain space downstairs for the actual garage part of the garage! The stairs will be in an entrance area outside the live room.

Yes, I do mean those concrete blocks I'm not so worried about isolating noise from outside, simply between the control room and live room. I've been in too many project studios with poor isolation between the live room and the control room to an extent that you may as well leave the door open. They'd tried to soundproof it, but hadn't quite got it right or had tried to keep their budget down too much. If you're spending money on it, you may as well get it right eh?

Alternatively I could have the studio taking up the whole of the upstairs which would allow the live room to have a larger floor area, however the actual usable space would be reduced by the sloping walls (and how would these affect acoustics?). Could this be a consideration?

 

[RICK FITZPATRICK]

Could this be a consideration?

I wouldn't. Impact noise on a common(to both rooms)wood membrane floor is awfully hard to isolate from each other. Even if KIP type iso flooring products are used, the membrane floor can structually transmit to walls etc. Thats not saying it can't be done, but personally, I'd go with the live room on a slab, and the control room floor isolated from the ceiling below.
fitZ