Is this space possible?

OK.... been doing my research, trying to turn my low nasty little tin garage into a usable space...... PLanning on building across the back of the entire garage, bulking up against the tin (roof inclusive, to create a sealed 1st leaf, then building entire uncoupled walls and ceiling structure inside this to create the 2nd leaf. The internal space after this will be represented in the attached google sketch up model. It is somewhat similar sized space to the 20' container studio on Johns built studio page.... which i like the layout of. FYI - http://www.johnlsayers.com/Studio/Image ... plan_2.jpg One major difference to that studio design is that i am trying to create some height in the space by following the rake of the garage roof, which from my calculations is approx. 12.85 degrees.... I have read here that 12 degrees is a good angle, so realistically if the additional .85 is bad then i can re-pitch the inner structure to suit. Im hoping to create an internal wall through this space to create a live room and control room. As for the best dimension of each i'm not sure if there is a ratio for this? I was playing with the idea of making the recording space approx 2.3m long....but is very close to the width (2.27m) which i know is no good, but will then putting in panel absorbers etc (accoustic treatments) change the dimension of the room, thus removing the square room issue? I want at least this size so i can fit drums... This would then leave the control room approx. 3.176m long, by 2.27m wide.... I was planning of having side doors leaving each space and just a window to see through to the live room (unlike the container design) The other issue with the above room sizings is that the ceiling raises up towards the front of the room then back down again before the front wall....is this a problem, would a cloud bridging this space be a solution? My dimension for the internal wall i worked out to be .224m,(double wall, 70mm studs, 2x16mm gyp) The dimensions of the internal space are to be: Total Floor Area - 5.7m long, 2.27m wide Roof rake starts at a horribly low 1.86m, to 2.508m hopefully the attatched sketchup doc helps paint the picture.... SO appart from all the above.....One big question remains.... Is this space so unsuitable that it will be impossible to make it work? Oh and as for budget, well I'm prepared to spend what it takes to build the end design, given that I'm pretty handy with a hammer, plasterboard etc, its all just material cost for me, and given my occupation (builder) a lot of it can be gathered off site (left overs etc) I calculated that it would take approx. 20tube of green glue to do the entire internal leaf...which is about $700aud and i'm prepared to spend that...build time will take a while so i'll construct as funds allow or materials become available Cheers Geordie

Dit a bit more work on the sketchup model...still learning that one....

Hi Geordie, and Welcome! :)

bulking up against the tin

It would be good to see some photos of that tin, and how the whole garage fits together right now, to see what you can do. Thin metal sheeting is not a good material for isolating (unless it is thin LEAD sheeting... :) ). You might need to do something to damp that, so it doesn't vibrate and rattle.

12.85 degrees.... I have read here that 12 degrees is a good angle, so realistically if the additional .85 is bad then i can re-pitch the inner structure to suit.

12° is about the minimum angle that is any use, assuming that you are trying to deal with flutter echo. If you are looking for an RFZ design, then you'll likely need a much larger angle, especially for a small room with a low ceiling. So you don't need to peg 12.000000° on the dot: It's just a guideline for the smallest angle that will work well. Of you can get more, then great.

Im hoping to create an internal wall through this space to create a live room and control room.

You didn't mention how much isolation you need, and your SketchUp model doesn't show the isolation plan, but it seems that you might not have the full picture of what you need for good isolation. You might already be considering this (not clear from your post), but it does no harm to repeat it: Just one wall across the room to split it in two is not going to give you much isolation at all. Maybe 30-something dB, if you are lucky, and assuming that you have no flanking paths (unlikely assumption!). To get good isolation you need to build not just one wall, but two entire rooms. After beefing up your existing outer-leaf (assuming that it is only one leaf at present) then within that shell you need to build a simple stud frame for your CR, and another simple stud frame for your LR. Put drywall on only ONE side of those studs, and that creates your inner leaf. The new frames cannot touch the existing structure at any point: not even a single nail. They also cannot touch each other. Each room is an independent structure, 4 walls plus ceiling, and the only thing they have in common is that they both sit on the same concrete slab floor of your garage.

As for the best dimension of each i'm not sure if there is a ratio for this? I was playing with the idea of making the recording space approx 2.3m long....but is very close to the width (2.27m) which i know is no good,

Correct: not good. Especially considering that those two are probably pretty close to the average room height as well. You might want to consider changing that somehow. But we are talking about the LR here, so ratios are not as critical as for a CR.

but will then putting in panel absorbers etc (accoustic treatments) change the dimension of the room, thus removing the square room issue?

No. The room is measured to the boundary surfaces of the inner-leaf: in other words, the walls, ceiling and floor surfaces that you see as you stand inside the room BEFORE you put any treatment or furniture in it. What you see after you finish building the new walls, as you are cleaning up and getting ready to bring in the speakers for the first test. That's the inner leaf, and that's what matters to sound waves. Treatment doesn't change that. (OK, well, some types of treatment can change that locally, such as maybe panel traps and soffits, but the concept is that the initial calculations and ratios are figured using the inner-leaf bounding surfaces).

I want at least this size so i can fit drums...

:shock: :!: :shot: How much isolation did you say you need? Drums are the toughest instrument to isolate! Loudest, most low frequency energy...

This would then leave the control room approx. 3.176m long, by 2.27m wide....

Small, but usable. If that's all you have, then that's all you have!

The other issue with the above room sizings is that the ceiling raises up towards the front of the room then back down again before the front wall....is this a problem,

Yes it is a problem! It is backwards from what you need!

would a cloud bridging this space be a solution?

I doubt it. The issue is that the rear of the room is smaller than the front, and the entire ceiling is reflecting sound back towards the mix position, instead of away from it. You'd have to make a cloud for the entire ceiling! That kind of defeats the purpose... Just turn the room around, so you are facing the low end of the ceiling.

Is this space so unsuitable that it will be impossible to make it work?

If that's the space you have, then that's the space you have! It's not going to be Abbey Road, but it can still be usable, if designed and built carefully. - Stuart -

It would be good to see some photos of that tin, and how the whole garage fits together right now, to see what you can do. Thin metal sheeting is not a good material for isolating (unless it is thin LEAD sheeting... ). You might need to do something to damp that, so it doesn't vibrate and rattle.

Yes sorry, the sketch up shows no detail as to my plans for isolation, partly because i'm feeling reasonably confident with this part of the concept, much more confident than i am with using sketch up. So the model ive provided so far is purely the internal space left post a fully isolated double wall set up where the inner leaf/wall is completely free of the outer, no attatchment etc etc... including that internal wall it is double wall two leaf construction (MAM), 32mm of fire check either side and green glue between that etc. And the ceiling joist of this internal leaf will both be bearing on those walls, essentially creating two free standing rooms with in the garage. As for the garage its self i plan on beefing up directly against the tin with gyprock again. Ive been reading the book "Home recording studios, build it like the pros" by Rod Gervais and has been exceptionally helpful. It has a cross section of the exact senario of my garage and i plan to replicate that. If you happen to have the book, im referring to figure 10.17, section through garage wall. Ill post some pics up of the garage also so you can see what im working with...I have my work cut out, but as mentioned, im pretty handy, and pay attention to detail. The first step is remove roof/wall sheeting and wrap the whole end of the garage in closed cell sisalation foam wrap to prevent condensation etc against the gyprock. The stuff i plan to use it a dense foam wrapped in silver sarking both sides which should dampen the tin itself and like i mention prevent condensation rotting the gyprock that will be hard pressed against it.

Just turn the room around, so you are facing the low end of the ceiling.

And thats why im here :D avoid those sorts of mistakes!!

How much isolation did you say you need? Drums are the toughest instrument to isolate! Loudest, most low frequency energy...

I live in a reasonably quiet street, so external noises arent a major issue, but obviously with drums they are noisey (neighbours kid has them to) so i prepared to provide (my neighbours) as much isolation as 32mm of gyprock + insulation on external leaf + 32mm gyprock + greenglue + accoustic insulation on internal leaf provides. I can then put my hand on my heart and say honestly that i have gone some lengths to isolate the noise of my drums. Much much more than the kid next door in the double brick garage. (which conveniently enough is the closest dwelling to the garage). Hopefully the attatched pics will shed some more light on the garage itself. IN the meantime im going to attempt to recreate the cross section from the book in paint to illustrate my plans for the outer leaf. Will be using this same method on the roof also. As the walls and roof of the garage are of the same construction, Hopefully the pic also shows the truss section that are constraining the width of the studio space. I will also upload a photo of a hand sketch ive done on how i plan to treat the inner truss and incoporate it into the outer leaf. The only real issue i can see is the flanking noise from the roof battons that run through and im considering trying to devise a way to decouple these battons....but might wait to see if it a massive flanking issue or not first... But to anyone else who might be interested, that book is a good read.

And here is my paint recreation of garage wall cross section. I left the insulation out, but you know where it goes...and in my instance it might be to thick...possibly better putting another layer of gyprock in, as the batton on my shed are only 50mm thick (50x75, they are spun the other way round for the roof battons)...so another 16mm of gyp (more mass) would probably help more than insulation that could possibly cause a cavity breach to the next leaf? Am i right?