John Sayers' Recording Studio Design Forum Archive

Hi guys.

First and foremost I am SO glad I have found this forum - I've been glued to it for about 6 hours solid. I am in the early stages of my project which I will outline the summary of below and hope to get some assistance with (what are probably quite basic) questions I have.

I live in Sussex UK, and have a spacious garden in which I have built a concrete shed base in preparation for a drum rehearsal room. The shed base is not quite square (intentional) but for the purposes of my post I will talk as if it is (its close enough). Its about 6m x 3.8m (20ft x 12ft approx). The shed base is build properly on a decent sub base with a membrane etc etc and is straight on "earth" and it not connected (or anywhere near) any other building. I plan to build a room within a room most likely be:
(outer) some sort of presentable cladding > OSB > DPMembrane > stud (4x2 insulated with 75mm RW3 Rockwool) > air gap > stud (same) > audio grade drywall > green glue > audio grade drywall (inner)

I had planned, prior to discovering this forum, to float the floor on some dense rubber matting I have been gifted. The best way of describing these are "rubber safety tiles", the sort found in children's playgrounds. I would have then build a timber stud floor on top insulated in much the same way as the walls - however this seems highly unnecessary - based on the majority of info on here.

I am a competent DIY'er and keen musician - not an engineer or studio designer so sorry if my questions seem a bit daft.

1. Without sounding daft if the outer wall is sitting on the concrete slab - and the inner wall is also sitting on the same slab (albeit separated by an air gap) does this concrete not effetely "couple" the two leaves? Should I float my inner wall on these rubber tiles I have ?? Or does having an inner wall and an outer wall (even sat on the same concrete slab) still count as a decoupled wall?

2. If I leave my concrete slab as is - is there any benefit to insulating it in any way? Or shall I literally just put some form of flooring down (most likely carpet) and if so over way - I can really lay carpet straight onto rough concrete surely?

3. If there any better use for the rubber tiles? I have them already, they are free, good mass and must be of use somewhere if not in point1.

Grateful for any assistance officered.
Mark - Sussex, UK

EDIT: I have since found a similar post a few years old where the advice offered was to caulk down the length of the plate prior to securing it to the concrete - makes perfect sense. I am just worries (probably unnecessarily) that both the inner plate and outer plate are obviously being screwed to the same concrete slab. Clearly gravity dictates the walls have to sit on something but just making sure both inner/outer wood plate is fine to sit on the concrete slab - or should I sandwich something more than caulk between the wood and the concrete?

anyone??

Can anyone answer my question ??

Relevant to your other post re neoprene under sole plates I would suggest that you float the inner walls on neoprene to decouple the inner walls from the slab.
I would also float a floor on 3 x 2s on side, 400mm OC with neoprene under.
cheers
john

John Sayers wrote:Relevant to your other post re neoprene under sole plates I would suggest that you float the inner walls on neoprene to decouple the inner walls from the slab.
I would also float a floor on 3 x 2s on side, 400mm OC with neoprene under.

floor.JPG

cheers
john

Thank you very much John.
I'll still need to screw the inner wall down into the slap confirm ?
But use a layer neoprene between the inner plate and the slab to fill any air gaps basically because my concrete obviously isnt glass-smooth.

Any specific thickness ?

Yes, use a layer of neoprene for your inner walls. Use the stuff you mentioned for playroom floors - use a Stanley knife to cut it into 4" wide strips.

You'll find the rubber mounted floor wonderful to walk on and drummers tell me their kit sounds great on it.

cheers
john

Brilliant.

Neoprene under inner wall - TICK
Still do screw the inner wall to the slab - TICK
Make use of rubber tiles I've got (granulated rubber sort) to go under drum kit - TICK.

You've been really helpful thanks.

in theory wouldnt it be better to not screw the inner wall to the slab, but leave it floting even more freely?
is this more structural and safety point than acoustical issue or is the effect acustically so small that it doesnt matter?

sorry for stupid questions, I'm here to learn

a couple of screws really doesn't matter.
cheers
john

John Sayers wrote:Yes, use a layer of neoprene for your inner walls. Use the stuff you mentioned for playroom floors - use a Stanley knife to cut it into 4" wide strips.

You'll find the rubber mounted floor wonderful to walk on and drummers tell me their kit sounds great on it.

cheers
john

John
Sorry need to seek clarity.
Float inner wall specifically on neoprene (I.e buy some) OR ok to use the rubber tiles previously discussed cut into 4in strips? Just want to be sure I understand your advice.

Also - the image posted suggests the pieces of neoprene are spaced - my assumption would he a continuous strip around all four edges with not gaps beneath.

There's a 4" strip of rubber (whatever you've got) continuously under each 3 x 2 floor joist.
cheers
john

Been a few months off - something came up in the house and quite literally sapped my funds. However back on it now.

Based on advice up this thread I now understand the limited value in even contemplating trying to float the floor. And John - based on your advice I will be recycling the rubber matting to separate the wall plates from the concrete block - accepting that they will be screwed down - so technically will short circuit" the isolation - but a limited amount - and I am benefiting from this whole studio being in the corner of a garden. The walls have to be secured somehow right???

See diagram.

Thoughts gratefully received.

spesh99 wrote:Been a few months off - something came up in the house and quite literally sapped my funds. However back on it now.

Based on advice up this thread I now understand the limited value in even contemplating trying to float the floor. And John - based on your advice I will be recycling the rubber matting to separate the wall plates from the concrete block - accepting that they will be screwed down - so technically will short circuit" the isolation - but a limited amount - and I am benefiting from this whole studio being in the corner of a garden. The walls have to be secured somehow right???

See diagram.

Thoughts gratefully received.

Hi,

Yes bolt your sole plates for each frame down firmly into the slab. The neoprene strip is really there to compensate for any unevenness between the timber and the concrete - it fills little gaps to ensure a better air tight seal.

I don't understand your simple diagram though - your outer leaf has the drywall inside the cavity but shows nothing on the outside of the studs, obviously you can't leave it open to the elements so what are you going to put there to weather proof the whole structure? Just a word of advice, it would be better to put all your mass on the outside face of the studs rather than inside the cavity, it will increase your air gap, avoid a three leaf assembly and be simpler to build.

Also, make sure you fill the cavity entirely with low density fluffy fibreglass insulation.

Have you figured out your roof/ceiling assembly yet?


Paul

Paulus87 wrote:

spesh99 wrote:Been a few months off - something came up in the house and quite literally sapped my funds. However back on it now.

Based on advice up this thread I now understand the limited value in even contemplating trying to float the floor. And John - based on your advice I will be recycling the rubber matting to separate the wall plates from the concrete block - accepting that they will be screwed down - so technically will short circuit" the isolation - but a limited amount - and I am benefiting from this whole studio being in the corner of a garden. The walls have to be secured somehow right???

See diagram.

Thoughts gratefully received.

Hi,

Yes bolt your sole plates for each frame down firmly into the slab. The neoprene strip is really there to compensate for any unevenness between the timber and the concrete - it fills little gaps to ensure a better air tight seal.

I don't understand your simple diagram though - your outer leaf has the drywall inside the cavity but shows nothing on the outside of the studs, obviously you can't leave it open to the elements so what are you going to put there to weather proof the whole structure? Just a word of advice, it would be better to put all your mass on the outside face of the studs rather than inside the cavity, it will increase your air gap, avoid a three leaf assembly and be simpler to build.

Also, make sure you fill the cavity entirely with low density fluffy fibreglass insulation.

Have you figured out your roof/ceiling assembly yet?


Paul

Thanks Paul
No - in truth I have not worked the roof out.
Sorry the diagram is very simple it was more to illustrate the plates / neoprene and drywall. You are very right externally it wont be left like this.
I will most likely (once the voids are insulated), OSB board the whole exterior, add a membrane and then cladd it a yet to be determined cut of wood.

So something like (out to in)

Cladding
Membrane
OSB
Stud Wall (insulated)
Drywall
air gap
Stud Wall (insulated)
drywall
GG
drywall



Roof i need to work out - complicated
more by the fact the shed wont be perfectly square (long story and I accept complicated but doesn't really change how i build it in terms of insulation etc.

Roof advice very welcome indeed.