If you use the search feature at the top right hand corner you may just find most of your questions may have been covered in previous threads here on RO.
There is a wealth of information also below the bottom of this thread in regards to building home studios so its also worth looking there also.;)

Get this book, and read it before you do anything:

https://www.amazon.com/dp/143545717X/?tag=r06fa-20

Welcome to RO!!!!

+1 on the book. You and your contractors will need it. It's the first thing you should get, even before reading the rest of this post. Lol. Its opened many doors for me, and saved me/my clients tons of money, over the years.

I'll try to answer your questions concisely as each question could have several books dedicated to them.

1. No. You do not need to float the interior room. There are several practical options. A good starting point would be a basic reinforced concrete slab. Your outer walls and inner walls would both be built on this. earth dampened concrete is excellent at stopping sound transmission. for practical purposes it will not be the weak point in your assembly. Forget about floating anything, it's not necessary in your case.

2. You have several. Most important is the ability to plan and design a good sounding space with no pre determined Boundries, plumbing, Ect. It's cheaper to build new. You have the advantage of designing optimal size and shaped rooms, to deliver the best quality you can afford. Already significant isolation from the house, which most residential studios don't have. So have the ability to save money by planning. You take advantage of this by planning your studio along with a professional studio designer builder. This save time, money, aggravation, and delivers a final product with a fairly predictable outcome. Mechanics don't design cars, they work on them, in the same light (most) contractors don't design studios, but they should be capable of following the prints and doing the actual carpentry Ect. Not living with a 3 year construction project inside the home is a huge advantage for peace in the home.

3. A general way to think of insulation application is, if it's behind the wall or a closed cavity R- type fluffy insulation is used. If it's acoustic treatment inside the room, that's where the Rigid insulation comes in, i.e. Roxual, Owens and Corning. Think of roxoul in the applications you would put 'studio foam'. Obviously this depends on local building codes, and some may specify the use of roxoul or 'fire safe' insulation within the wall cavities.

4. Depending on budget and isolation requirements and building codes, both are acceptable. A common thing is to have a concrete block outer shell, with a wood framed/drywall interior. A wood framed outer wall could also be used. It takes time to decipher what the best if for you based on a cost benefit analysis. Drywall is probably the most common wall covering for studios. It's the most efficient means of isolation in a cost per sqf situation. I.e. It isolates, well, is relatively cheap, and fairly fast/painless to install.

4a. You'll see numerous illustrations in the book of wall assemblies. But NO, you do not want a wall in between your inner and outer shells. This would actually make things Worse. You want one larger outer structure on a thick slab, with a high ceiling, and as few support poles as possible. This outer structure is ideally very massive. On the inside of this large open structure, you have another set of walls that define your studio room(s). The inner room, built on the same slab, gets its own 4 walls, and 1 ceiling. The booth, same thing, on the slab, it's own 4 walls and 1 ceiling.

I picture it like a couple of garden sheds, inside of a warehouse.

5. Floors are generally kept live (no acoustic treatment). The option to use a throw rug is always available. Painted/stained concrete (right on your foundation which the booths are on) is a common way to finish floors, and is economical. Hardwood and laminates are also very very common, probably most common. you want to avoid building any sort of wooden subfloor, so you would want to glue/nail this stuff down securely. Floating floor coverings can squat and rattle. No good. There's plenty of ways to accomplished this, depending on design.

6. I'd have to double check the numbers but I think the BBC calls for a minimum of 1500 cubic feet, for rooms that reproduce vocals. 2500 cubic feet, is the minimum for a listening room, it might be 3500, I'd have to double check.

7. Both ceiling types have their advantages, and both can be used, again which one depends on overall design, and budget.

8. Those windows, which are drawn in the book, are generall two very thick, pieces of glass with one a bit thicker than the other. They are airtight. Well planned windows weigh as much as the wall covering. I.e., if you had three layers of drywall on one wall, you want the glass on that side be equal to or heavier than than the three sheets of drywall. This is expensive in general. 2 4x8 sheets of glass 3/8 and 1/2" thick, cost $2k for the last studio window I built.

9. Sky is the limit, and a basic small project studio in a basement doesn't happen for much less than $10k. In general studio construction ranges from $50-150+ per sqf.

10. Too many to list. First remember it's an airtight structure heavily insulated, you need fresh air, and cooling. Cooling even in the winter sometimes.

Don't hire anyone without seeing their work. Don't have your own bright ideas, the scientists already had them. Hire a professional to plan it. Have that professional keeping tabs the whole project, the contractor will screw up. Don't spend a penny on materials till you have your blue prints. There's many broke owners of half done studios.

Remember this, everything studio cost 3-5x more than the figures, and takes 3-5x longer than estimated. It's true. It's the 'hidden' costs that add up. Things like caulking are completely integral to a good airtight studio. It's expensive. And exactly the type of thing an inexperienced contractor building a studio, would deem as 'overkill' or 'unnecessary'. To him it's an easy to 'save cash and time' by omitting such a seemingly small detail. Not the case, and things like that can be detrimental to the final product. Trained eyes need to be on each phase of construction. This is a marathon not a sprint.

-Kyle.

Great advice there from Donny & Kmetal (y)

"9. How much do you think this project will cost? "

Approximately the square footage cost of a custom home in your neck of the woods as a rule of thumb.

Then only thing that I would offer beyond what kmetal has stated is this. If you are going to pour a slab anyway, have an isolated slab poured. You will break the path that vibration move on from the inside to the outside.

One caveat: If you build on rock....never mind since the two slabs will be bonded together so any benefit gained would be lost.

Attached files

I like the inclusion of the wooden saw horses in the illustration. Nice one.

I also made a working framing square. It's laying there on the form boards ;)

@Brien Holcombe kmetal

kmetal, post: 433135, member: 37533 wrote: earth dampened concrete is excellent at stopping sound transmission. for practical purposes it will not be the weak point in your assembly.

Brien, Kyle... this may be a dumb question ...

Would there be any benefit to having two separate slabs poured; to further the lessening of transmission within the structure - say, one slab for the live/recording area, and then a separate slab for the control room?

Even if the separation distance was as small as 1/16th of an inch, separate is separate, right? Or would this not prove beneficial in any redeemable way, and would it just be an extra unnecessary step?

( Understanding that there are coupled fields of transmission within the structure that would be of concern other than just the cement substrate. )

I'm just curious. :)

d.

DonnyThompson, post: 433176, member: 46114 wrote: @Brien Holcombe kmetal

Brien, Kyle... this may be a dumb question ...

Would there be any benefit to having two separate slabs poured; to further the lessening of transmission within the structure - say, one slab for the live/recording area, and then a separate slab for the control room?

Even if the separation distance was as small as 1/16th of an inch, separate is separate, right? Or would this not prove beneficial in any redeemable way, and would it just be an extra unnecessary step?

( Understanding that there are coupled fields of transmission within the structure that would be of concern other than just the cement substrate. )

I'm just curious. :)

d.

I'm pretty sure rod g said the power station (power station New England too?) had isolated slabs for each room. This is apparently a great way to go, and the way I would go with a scratch build. I believe that in general this is about all you'd have to do is most professional level builds. I can only imagine the next and final step would be to float these individual room foundations. Perhaps if you build your studio above a glass warehouse?

I've never done foundation work, or had it done for any of the builds I've done. All have been on commercial or residential foundations, and I've yet to have isolation problems after three builds in that nature. In fact the Normandy control is on wood decks, but actual separate building foundations. There were two closely adjacent buildings that they connected to make a large furniture store in the 50s. So when the studio was built (the first time out of four lol) in 72' they put the control room and lounge on the back buildings foundation/deck, and the rest of the studio on the other. Phil will tell you they filled the whole foundation/basement with sand (6' deep lol) right up to what is, the control room floor/deck. I dunno, the deck resonates when you stamp on in so, either it settled, which is entirely possible with that much weight And a know wet coastal area. Or it's just a pipe tale.

I've never had isolation problems with isolation in my builds, it usually performs about as expected. I haven't tracked a full band in Normandy to see how much of a problem the wooden deck is. I m sure they would have fixed it in the heyday if it was a problem. More money went into that studio over the years, than I'll be lucky to ever make in a lifetime. they got the whole double wall and double drywall thing right, the caulking, let's say a bit of an oversight. Things have come a long way with regard to the spread of better studio construction technique.

I'm not really sure about a rule of thumb for spacing between adjacent slabs. There was one build I think on John Sayers that made mix when it was done, and they used the spaces between the slabs for cable runs. One thing to consider is, a slab may have to have specially sized edges (i.e. Thicker perimeter edges) to support heavy duty walls, but this is all just stuff I've read. You can't just cut an existing foundation willy nilly, and expect it to work/last, and this sort of thickening of the perimeter of a slab comes into play. You basically dig/pour deeper around the edges. I believe Max's studios outer shell was built on a knee wall of concrete blocks. My memory is a bit foggy of the thread as its been down a couples years. I think it was a knee wall for the outer shell, and one slab for the studio. I'm not sure if there was any sort of isolation between the two. I don't think he went the route if independent slabs. His rooms has 1OSB and 1 or 2 firecode drywall layers with green glue. I think it was two layer of drywall... The rooms were independently framed walls and ceilings directly in the poured foundation. In fact he had a situation I just remembered where there was a spot in the foundation that was soft or cracked and it was a concern about how to attach the footer.

I know the foundation is a substantial part of the build cost wise, but extremely integral. I think you don't see a ton of floating or even isolated slabs because typical slabs will be able to keep up with what a wood framed structure can handle. I think any slab, that can handle structurally, the weight of studio walls and ceiling would, not be the weak point because of how dense and dapmened and reinforced it is inherently, as a support medium.

It's not an area I encounter much in the real world so most of the little I know on foundations is from text.

Post number 6 I made mentions the isolated slab...yes I would do it if building new and would consider it if the money was available and the isolation requirements warranted the extra work to retroactively develop the isolation goals.

Breaking the path is a tedious procedure but the gains far out weigh the work. Like mentioned it ain't for every geological situation but it is a first line of defense and everyone's knows that if the foundation is prepared correctly the hardest part is over.

In respect to cabling I would have conduct under the slab and sleeved at path breaks to ensure that the separation is maintained....since the conduit itself can become a path if not broken.

That is why I enjoy isolation so much...I get to break things!!! ;)

Brien Holcombe, post: 433184, member: 48996 wrote: Breaking the path is a tedious procedure but the gains far out weigh the work.

So the "ideal" situation would be to have two separate slabs... what's the difference between pouring separate slabs, and pouring a whole slab but then cutting it afterwards where it would be needed?

I'm not suggesting... I'm asking, because I don't know.

The difference is a lot of hard work to retro fit a slab inside an existing slab... a LOT of excavating the existing concrete, packing the existing Earth, etc.

Ideally, in the OP's case you develop the slab based on the design and you form and place concrete accordingly.

If you already have an existing concrete slab then you have to get a demo saw, wheelbarrow, shovels, a water hose, a sledge hammer and or a jack hammer. Starting to see the difference?