Double Garage Studio Design - Melbourne, Australia (7/10)

[rockindad]

Hey there, Great forum you've got going here - very helpful! I'm a long time lurker, first time poster.

I'm about to embark on fulfilling a lifelong dream of a dedicated studio/music/rock-god-lair \m/, I've read Rod Gervais' book - plus other articles...and many threads here so I think I have the fundamentals happening?

It's going to be a one room affair - with the main intention of being able to play/record guitars (loud!) and vocals without annoying the neighbours too much (not sure what that equates to in dB?). It is a hobby and not a livelihood - so I don't need to go to the nth degree, but I do want to do it well. I'm guessing my budget is in the order of $10k - as I'll be doing most of the work by myself..with a little help from my friends.



The walls are all brick, the roof is concrete tiles. The main panel door is going to go and be replaced with a cement sheet clad (x2 layers) stud wall.

I'm planning to use about 2/3 of the overall space. I want to leave a workshop at the back.



I have a neighbour about 5m to the right (from the front - you can just see their roof in the second pic), but that's my only real concern on that front.

The basic design looks like this. (Tried uploading the sketchup file, but it seems to be too big)







So the plan is to build a 'room within a room' and to add treatment once finished. The floor is a concrete slab. One of the side walls has a lounge room on the other side, that's the wall with no stud wall in the studio. My thought there was that with there being a stud wall on the inside of the house, that constituted a two leaf system, so I was going to simply add plasterboard directly to the bricks on the studio side to beef it up - does that work?

A question about the internal wall - I was thinking that and the rear external wall would form a 2 leaf system - but the air gap will be a workshop with stuff in it. Would I be better off adding a 2nd leaf to that internal wall, i.e. plaster on both sides...or does that then set up the dreaded 3 leaf system?

The ceiling is pretty low - 2330mm - so that could present some problems, but the overall dimensions of the room are reasonably generous, so I figure that should counter that to some degree(?).

Anyway, I'm someone could chime in with thoughts on the design at this stage - point out any glaring problems or potential pitfalls - or any other information I've left out. That would be greatly appreciated.

The only thing I haven't fully worked out is HVAC. I was looking for a low cost option...which is proving difficult to do in Aus. Ideally, I'd put in the Daikin split that has air intake...but at around $2k locally, I don't forsee that happening and I can't seem to find any 2 hose portable aircon units available here. So I may end up with a hybrid system consisting of an intake with a fan via a baffle and a passive return (again baffled), along with a smaller split system to handle cooling and help with humidity. Thoughts?

Cheers,

Scott

[rockindad]

So, couple of changes so far to the design:

1. Not going to have the framed rockwool on the wall with the pillars - leave that as an air gap
2. Current room dimensions (as per the diagrams) H: 2300 W: 4474 L: 5650 - still looking at whether these are OK with regard to room modes or a small change would help me any on that front? I want to utilise the space as much as I can and I'm hesitant to make it much smaller - and I'm out to the maximum on all sides really as well.
3.Ventilation: Finally had some thoughts on this area. I thought to use an in-line fan via a silencer and have a passive return that vents into the roof cavity.

Garage Studio Design - ventilation.gif

Any input is welcome.

Cheers

[Soundman2020]

Hi Scott, and Welcome!

The main panel door is going to go and be replaced with a cement sheet clad (x2 layers) stud wall.

That will be your weakest link, then.

The basic design looks like this. (Tried uploading the sketchup file, but it seems to be too big)

Two things: SketchUp does not really deleted things from the file when you hit the "delete" key: it just stops showing them. In order to actually get rid of them, you have to "purge" the file. On the "Model Info" window, go to the "Statistics" tab, and hit the "purge unused" button. It might take a few seconds, or even longer if you have a big model, but it cleans out all the geometry that is not active in the model. The save the model again, and try uploading it.

If it is still too big, then upload it to a file sharing services, such as DropBox, then post the link here.

My thought there was that with there being a stud wall on the inside of the house, that constituted a two leaf system, so I was going to simply add plasterboard directly to the bricks on the studio side to beef it up - does that work?

Nope! The surface density of a 4" (10cm) brick wall is about 230 kg per square meter. The surface density of one sheet of 16mm plasterboard is about 11 kg per square meter. so adding a layer of plasterboard directly on top of the brick wall, increases the mass by about 4%. You would need to increase the mass by about 200% to have any useful effect on isolation, and even then it would only be an increase of 4 to 6 dB. So one layer of plasterboard is negligible; it basically has no effect at all on isolation.

What you should do, is to build a proper stud frame in front of that brick wall, then put one or two layers of 16mm plasterboard on that, just like the rest of the room. The concept of "room in a room" is exactly that: you build a complete new room inside the existing room, including all four walls, and the ceiling, and the doors, and the windows, matching everything one for one, but with no physical contact at all. No part of the inner leaf can touch any part of the outer leaf.

A question about the internal wall - I was thinking that and the rear external wall would form a 2 leaf system - but the air gap will be a workshop with stuff in it.

Not really: what you would have there, is a single-leaf wall from the studio to the workshop (so very poor isolation), then another single-leaf wall from the workshop to the outside world.

Would I be better off adding a 2nd leaf to that internal wall, i.e. plaster on both sides...

Yep!

or does that then set up the dreaded 3 leaf system?

Nope!

The ceiling is pretty low - 2330mm -

That's fine. Higher is usually better, but 2.3m is OK. Some folks get by with ceilings considerably lower than that.

So I may end up with a hybrid system consisting of an intake with a fan via a baffle and a passive return (again baffled), along with a smaller split system to handle cooling and help with humidity. Thoughts?

Actually, that is the correct, best and recommended way to do it! You are spot on there. But do make sure you do the calculations, both for the heat and humidity loads on the split system, as well as for the air flow volumes and velocities in the ventilation system.

2. Current room dimensions (as per the diagrams) H: 2300 W: 4474 L: 5650 - still looking at whether these are OK with regard to room modes or a small change would help me any on that front?

Try these calculators:

http://www.bobgolds.com/Mode/RoomModes.htm

http://www.bobgolds.com/Mode/RoomModes.htm

Those are the two best ones that I'm aware of.

I want to utilise the space as much as I can and I'm hesitant to make it much smaller

Have you considered building one or more of your inner-leaf walls "inside out"? Or the ceiling? That can increase the actual volume of the room, acoustically, and also saves space for acoustic treatment.

3.Ventilation: Finally had some thoughts on this area. I thought to use an in-line fan via a silencer and have a passive return that vents into the roof cavity.

Not a good idea, and probably not eve allowed by your building code. It's always a bad idea to vent arm humid air into the attic space, even if it is ventilated up there. Much better to vent properly to the outside world.

Also, I prefer to put the fan on the exhaust duct, not the supply duct, for a couple of reasons. One of those is that you still get airflow if the door is open, whereas if you have the fan on the supply side, most likely there won't be any flow through the room. I would also not put the fan where you can't get to it easily: fans are reliable, yes, but they can still fail and do need occasional maintenance and cleaning... I like to put the fan some place where you can get to it very simply. Ditto for dampers, filters, etc.

- Stuart -

[rockindad]

Thanks so much for the input Stuart - much appreciated!

So I've updated the basic design...see pics.

Which makes the internal dimensions H:2300 W:4235 L:5600 mm

Especially thanks for the help RE Ventilation - I'll do as you're suggesting and make the return active and intake passive. I'm also thinking I'll put the intake near the door (ceiling mounted) and the return near the diagonally opposite corner - left of the window (top pic.) - aaaand, vent to outside. I'll update the plan on those points shortly.

Checked the Bob Gold mode calculator on the room dimensions - so, in trying to understand the information it's giving me - everything above about 80Hz is in the 'negative' with the dark green colour - I'm trying to work out if that is good / bad / or just something I'm going to have to sort out with treatment? Below that there seems to be good separation (good thing?), but I go into yellow (bad thing?). Rod's book seems to say room dimensions are important, but to a point. Just avoid cubes and whole number ratios and then treat what happens beyond that. Am I getting that right?

Thanks again for helping out.

Garage Studio Design - 3D - v3 rear 3-11-14.jpg

Garage Studio Design - 3D - v3 3-11-14.jpg

Here's a link to the sketch-up file so far.

https://dl.dropboxusercontent.com/u/355 ... -%20v3.skp

[Soundman2020]

Checked the Bob Gold mode calculator on the room dimensions - so, in trying to understand the information it's giving me - everything above about 80Hz is in the 'negative' with the dark green colour - I'm trying to work out if that is good / bad / or just something I'm going to have to sort out with treatment? Below that there seems to be good separation (good thing?), but I go into yellow (bad thing?).

What you are looking for, is reasonably even spacing between the modes. In other words, the modes should not be all bunched up together, nor should they be spread wide apart, or spread unevenly. It's impossible to get them perfectly even, of course, but that's the the ideal. As long as you aren't getting any "fail" under the three critical BBC tests, and as long as the Bonello chart looks reasonably smooth, then you are good to go!

Rod's book seems to say room dimensions are important, but to a point. Just avoid cubes and whole number ratios and then treat what happens beyond that. Am I getting that right?

Right! That's about it. Stay away from the bad ratios, get within spitting distance of a good one, and that's that. There's no need at all to be trying to tweak the last 1/8" or 1 Hz to get a "perfect" ratio, because there is no such thing in a small room!

- Stuart -

[rockindad]

What you are looking for, is reasonably even spacing between the modes. In other words, the modes should not be all bunched up together, nor should they be spread wide apart, or spread unevenly. It's impossible to get them perfectly even, of course, but that's the the ideal. As long as you aren't getting any "fail" under the three critical BBC tests, and as long as the Bonello chart looks reasonably smooth, then you are good to go!

Sweet - well I'm pretty close to that - cheers.

My next question is:

For the cladding on the front wall (in the garage door space...dark grey in the image below) - I am planning on using 2 layers of external rated cement sheeting (a.k.a. Blue Board) at 7.5mm each giving me a total of 15mm of cement sheeting on a stud frame - then render to match the existing finish. Is there a better and reasonable cost effective alternative that I'm missing or should I be adding/subtracting something? I was going to brick up the space, but the cost was a deal breaker.

Front wall cladding.jpg

I'll start a build thread soon, as I'm under way with small steps.

[Soundman2020]

I am planning on using 2 layers of external rated cement sheeting (a.k.a. Blue Board) at 7.5mm each giving me a total of 15mm of cement sheeting on a stud frame - then render to match the existing finish.

That should work very well. That's equivalent to about three or four layers of drywall (depending on how thick you render it: the thicker the better). The most important part of that job is getting a perfect seal where this butts up against the existing walls.

I'm under way with small steps.

That's the best possible way to build a studio! Small steps, and post regular design updates plus lots of photos as you go: it's like having many eyes looking over your shoulder, to make sure you are doing it right!


- Stuart -

[xSpace]

"I'll start a build thread soon, as I'm under way with small steps."

No need for a new thread. Just continue to use this one so we can keep all the small steps in one place

[rockindad]

So the build begins...

The internal partition frame is done.

Internal partition frame 11-14.jpg

Internal partition frame long shot 11-14.jpg

Started on the front external wall frame.

Front external wall frame beginings 12-14.jpg

Rain delayed play today, but the frame is under way. Hope to get that done in the next day or so, then I'll get the cladding and seal that sucker up. The tricky part will be attaching the top plate to the I-beam with very limited access to the upper side above the eave. Wish me luck!

[rockindad]

This is the window that is going to go in the front external wall. Dimensions 1540 x 460 mm. It is double glazed - but the gap between the panes is small. I'll probably end up putting a sheet of thick laminate glass on the internal wall when I get there.

window for front wall.jpg

[rockindad]

Progress.

Front external wall frame progress 12-14.jpg

I'm thinking about the cement sheeting and the space above the window. I wanted to keep the window as high as possible, but I'm worried that a 90mm section might be too small and end up cracking? Any thoughts?

[grapefruit]

IMHO The window would look better a little bit lower...

[xSpace]

"but I'm worried that a 90mm section might be too small and end up cracking?"

Is your concern that a 90 mm piece of Durock is going to crack? Or are you concerned that the actual window or framing will crack?

[rockindad]

The sheeting.

[xSpace]

It is always best to have solid backing behind the sheathing and use a nail gun. But if you must hand nail...the solid backing cannot be over emphasized.