Building rehearsal/recording room in garage.

[jett_11]

Hi. I have posted on the forum previously when i was building my mix room. I followed all the advice the hugely generous admins on here gave me and it turned out wonderfully well so i am back seeking advice on my new project.

Project Outline:
I need to construct a room inside of my existing two car garage.
I will be principally using the room to rehearse in with my rock band. We typically play at around 120db. I will be tracking demo drums in there but that is a distant second priority to rehearsal.

Requirements:
I need to reduce the sound bleed as much as is possible. This is the priority over and above the acoustics of the room itself.
Create as large a room as is possible given the restrictions of the garage dimensions (namely the over hang caused by the roller doors and the support beam that runs across the centre of the garage)

Budget:
All in I am looking to spend no more than $11,000

Location
I live in a town house. The garage is located 20m away from neighbours' housing and is situated in a row of garages.

Construction of existing garage
-Walls and roof: Stainless steel
-Floor: Sandstone pavers (presumably laid on top of the earth but unable to check). Also, the floor has a definite slight slope to it but I'm unsure how to accurately measure to what extent it is not flat.

Already Established Plans
I will be purchasing a Daiken Ururu Sarara 7 as the HVAC unless a cheaper but equally effective alternative can be suggested.

QUESTIONS:
1. Will using the wall and wood floor construction that John Sayers outlines in his online studio construction book be the best way to go or should i be exploring the Genie Clip style design (given that sound bleed reduction is the priority)?
2. Will i need to pull up all the sandstone pavers and level the floor?
3. Will the ceiling of the room have to be placed below the steel beam that runs across the centre of the garage or can i somehow design around this to get the maximum room height?
4. Given that i want to use the maximum width (5200mm) of the garage what depth should i make the internal room (given that the roller doors take up about 400mm in depth when they are rolled up)?

I can't tell you how much i appreciate this forum and how humbling it is to see how generous the admins are with their time. I hope that asking for a second round of advice isn't pushing the bounds of good will.

[Soundman2020]

Hi there "jett_11", and welcome back to the forum! It's always nice to have repeat customers, coming back for a second round of grueling punishment... err sorry! I mean ecstatically enjoyable studio building!

I need to construct a room inside of my existing two car garage. I will be principally using the room to rehearse in with my rock band. We typically play at around 120db.

That's a pretty common request around here! 120 dB sounds about right for a loud band, but how quiet do you need to be outside? Is there a legal limit on that, or just a moral/ethical limit? Either way, you should put a number to it: the materials and methods that you'll use to build this place very much depend on that number.

I need to reduce the sound bleed as much as is possible. This is the priority over and above the acoustics of the room itself.

Right! But "How much"? That's the question. See above. You need to come up with a number that represents how much attenuation you want from your studio.

All in I am looking to spend no more than $11,000

Depending on how much isolation you need, I'd call that budget either "do-able but tight" or "unrealistically optimistic": Isolating a garage to 45 dB is one thing. Isolating it to 75 dB is quite another. Two entirely different budgets.

-Walls and roof: Stainless steel

Ouch! You have your work cut out for you. Not a good starting point...

-Floor: Sandstone pavers (presumably laid on top of the earth but unable to check).

Is there any way at all you can find out? Check original plans? Ask around with neighbors? Located the contractor who built it and ask him?

Also, the floor has a definite slight slope to it but I'm unsure how to accurately measure to what extent it is not flat.

Not a good sign. It makes your job a bit harder. There are several ways you could measure the angle, but even just estimating it roughly with a long spirit level and a tape measure is a good start: Lay a spirit level flat on the floor, following the slope, then slowly lift the low end until the bubble shows level. Now measure a know distance along the level from the tip that is still resting on the floor, then measure down from that point to the floor. For example, if you like imperial then measure two feet along the level, then what fraction of an inch it is directly down from that point to the floor. Or if you like metric, then measure one meter along the level, and see how many mm it is down to the floor. That won't be entirely accurate, but will give you a pretty good idea of the slope.

I will be purchasing a Daiken Ururu Sarara 7 as the HVAC unless a cheaper but equally effective alternative can be suggested.

Did you check that it is suitable for that size space, and that occupancy? There are tables and calculators for figuring that out...

1. Will using the wall and wood floor construction that John Sayers outlines in his online studio construction book be the best way to go ...?

You probably don't need a floating floor (read this: http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173 ), but you might well need to do something to that floor.

or should i be exploring the Genie Clip style design (given that sound bleed reduction is the priority)

Genie clips won't give you as much isolation as a full decoupled two-leaf wall on separate frame. You are starting out form a lousy position (thin steel walls), and you need major isolation (120 dB rock band...), so you are going to need heavy isolation. Genie clips won't get you there.

2. Will i need to pull up all the sandstone pavers and level the floor?

Possibly. It would be good to know what is under those: if they are just laid on the bare earth, then yes, I would pull them up and pour a proper slab. If there is already a slab below, then you don't need to do that: a layer of self-leveling cement might do the job.

3. Will the ceiling of the room have to be placed below the steel beam that runs across the centre of the garage or can i somehow design around this to get the maximum room height?

Not necessarily. It might be possible to soffit-in around the beams, and also around the garage door mechanism. It's more work, more expense, but does allow you to keep the maximum height.

4. Given that i want to use the maximum width (5200mm) of the garage what depth should i make the internal room (given that the roller doors take up about 400mm in depth when they are rolled up)?

That depends on your "number"! Remember that? From a few paragraphs up! There are equations for figuring that out, based on the all-important "how much isolation do you need?" number.

However, a roller door is not much use as an outer leaf, and neither is the thin metal shell that you have right now. I'm thinking that this might be one of those cases where you have no choice but to so a three-leaf isolation system, and compensate for the negatives of doing that.

In order to isolate, you need to have two entirely air-tight, completely sealed shells: One is your "outer-leaf", which is normally the building structure, and the other is your "inner-leaf", the actual "room-in-a-room" that you build to make your studio. But there's no way you can seal a roller-door air-tight! So it can't be used as your outer leaf. Therefore, you'll need to build another leaf just inside the roller door to act as your real outer-leaf.

Please post some photos of the actual garage, in as much detail as you can, so we can get a better idea of what you are facing.


- Stuart -

[jett_11]

I know what you mean about the gruelling punishment sensation! Just doing the comparatively tiny work that it took to do my mix room I had to keep chanting the mantra that my studio builder friend Erik often repeats "No one is going to do it for me".

I have done some further research etc in response to your very helpful responses:

Isolation required
Having checked the local ambient noise at night with an SPL meter and found out the local db level limits for daytime and nighttime in my area it turns out that i will have to isolate 65-70db (giving an outside noise when the band is playing of 50-55db)

Existing Garage construction
I have found that the pavers are laid on sand on top of gypsum or something similar so i will have to pull them up and pour a slab.

Budget
Given the ludicrous level of isolation required, having to build a structure inside the shed to house the actual "room inside a room" and the fact that i will have to pour a slab I have raised the budget to $15000. However if i cannot get that level of isolation for this budget (given that i can do all the labour myself) I don't think i will be able to continue with this concept.

QUESTIONS
1. Do you think that the level of isolation required is possible to achieve given the site restrictions and budget but bearing in mind that i am able to do the construction labour myself?

2. What type of construction would recommend for the "outer-leaf" room? Could i build it out of concrete cinderblocks?

3. If I shouldn't use the floor construction technique outlined in John Sayers online book, what floor construction technique should i use for the internal room?

4. Is using John Sayers "inside-out" wall construction style going to offer the best isolation or is there another construction method that i should use for the inner room?

Unfortunately my garage is currently full of junk so the photos i have taken are limited by that fact. (my garage is the two central doors in the photo)

[Soundman2020]

it turns out that i will have to isolate 65-70db

Ouch. That's quite high. Not impossible, but it will require careful work.

giving an outside noise when the band is playing of 50-55db

Did you take into account the attenuation with distance? The normal place for measuring the sound level outside a building, is 1m (3 feet) from the wall, but if the closest neighbor is 20m away (for example) then you have 19m of air that is attenuating the sound too, and at 3 to 6dB drop per distance doubling, a level of 60 dB at 1m would likely be down to between 45 and 50 dB at that distance. So you might not need as much as you think.

I have found that the pavers are laid on sand on top of gypsum or something similar so i will have to pull them up and pour a slab.

Probably a good idea anyway. It gives you a much better base for the entire project, and you'll even be able to entirely decouple the new slab from the existing structure, which is excellent. So your studio will be built entirely on that separate slab, while the existing shell of the garage will remain where it is, on its own foundations.

1. Do you think that the level of isolation required is possible to achieve given the site restrictions and budget but bearing in mind that i am able to do the construction labour myself?

At a rough estimate, I would say it is do-able on that budget. The only item that might be a big factor, is the HVAC. Have you quoted that yet? I haven't done the calculations, but at a rough guess I would expect that you'll nee a mini-split system in the range 18,000 to 24,000 BTU.

2. What type of construction would recommend for the "outer-leaf" room? Could i build it out of concrete cinderblocks?

For high levels of isolation, that would be an excellent start! Isolation needs mass. Lots of isolation needs lots of mass, and concrete has lots of mass. So any type of wall and ceiling material that has very high mass is a good idea.

3. If I shouldn't use the floor construction technique outlined in John Sayers online book, what floor construction technique should i use for the internal room?

If you are going to pour a new concrete slab. then you are done! That's about the best possible floor you can get, acoustically. Many, many studios just use stained concrete for their floors. Fantastic isolation, and excellent acoustics. However, if you don't like the look of concrete (some people don't), then you could lay laminate flooring on top, or ceramic tile, or even linoleum: As long as the final surface is hard, solid, massive and reflective, and has no air space under it, then it should be good. On the other hand, not doing anything to the concrete, just leaving it as-is, can save you money...

4. Is using John Sayers "inside-out" wall construction style going to offer the best isolation or is there another construction method that i should use for the inner room?

You could go inside-out, for sure. It has advantages, such as giving you great absorption all around the room and allowing for easy installation of additional treatment. Or you could also go with conventional construction, which is a bit easier to do if you are working entirely by yourself, but does mean that you'd then need to put up a lot of treatment on the walls. Or you could even do some walls "inside-out" and others conventionally.

so the photos i have taken are limited by that fact. (my garage is the two central doors in the photo)

That's pretty much what I figured. That tin shell is not going to do much for you, for isolation, and will probably be working against you to a certain extent. Those huge gaps between the walls and ceiling mean that right now there is basically no isolation at all.

So I'd say that your plan to go with concrete blocks as the outer leaf, with stud-and-drywall for the inner leaf, and all of it resting on a new, independent monolithic slab, is a really good option. One issue that you'll still need to solve, is your outer-leaf ceiling, and how to get lots of mass on that, but overall it looks like you have a feasible plan.


- Stuart -

[jett_11]

Thanks heaps Stuart, I am beginning to take steps towards beginning this project now. Exciting and terrifying steps but steps non-the-less.
I have redone my budget in a little more detail and it looks like i can cover it with $15k.
I think i am going to go ahead and use the "inside-out" wall construction technique on all the walls and the ceiling of the inner room.
Given that am investing what feels like an epic amount of money I am now committed to making the room sound as wonderful as it can for tracking drums. And with this mad desire come a whole host of other questions for me to pester you with. Apologies.

Requirements:
I need to track drums in the room however I do not need to monitor in there.

QUESTIONS

1. How close to my outer-leaf concrete block wall should i build the inner leaf "inside-out" wall? Should the outer insulation be touching the concrete block?

2. How should i treat the room in order to make it most ideal for tracking drums? e.g. Should i put "super chunk" bass traps in the corners of the room? What part do the slat resonators in Johns inside-out wall design play in this?

3. Do you have any suggestions about how i can add mass to the ceiling of the outer concrete block room?

4. I have seen a few different equations to use in order to calculate the ideal room size and i unsure about which to apply to a drum tracking room. Any advice on this would be hugely helpful. I am only working with very small tolerances in this area because I will be working in concrete block dimensions in order to keep the construction of the outer wall as simple as possible. At the moment the Outer room is 12 blocks wide by 13 blocks deep by 13 blocks high (each block is 390mm x 190mm x 190mm). So i could reduce a block length in either width or depth but i can't lose any height. I'm nervous about these dimensions as i seem to be building an almost perfectly cubic room which i have been told is the anti-christ of acoustic goodness.

5. When i construct the inside-out wall sections, should i be attaching the two pieces of plasterboard together incorporating green glue?

6. I can foresee at some stage wanting to link this room to my mix room. Is it best to deal with the installation of a wall plate during this construction or is it a simple retro fit to complete after the build is complete (given that i have concrete block outer wall and an "inside-out" inner wall?

7. If i should do the wall plate installation now, can you suggest the best way to go about it so that i don't ruin all the effort i will have gone to in order to stop sound escaping?

Please see attached a couple of photos of the mix room that i put together thanks to your sage advice.