John Sayers' Recording Studio Design Forum Archive

Hello everyone! May I say this board is fantastic. I believe I have read all the pertinent data, and it is with slight nervousness I begin…

What began as a simple roof replacement on my the crappy, L-shaped, totally unsoundproofed, studio has revealed massive work needed to be done, the whole ceiling and a couple walls had to go.

The upside, it will be remade as a much better work space.

It was originally a carport and is attached to the side of the house, it measures 13.5 x 18.5 feet. The ceiling at the house side is 10.5 feet, and at the other side 7.5 feet. The long wall opposite the house is made of cinderblock. Below the floor is a concrete slab.

I am putting the roof back on in a few days, but then am going to plan carefully how to finish the inside.

I use the studio both for my tv composing work, and to record bands, mostly my own, it is a 2 gtr bass drums keys. we get a little loud, (whatever that means) but not extremely so. I like all in one room live band recording, and the studio will have nice access to 2 small concrete rooms in basement where loud amps could be,

I have neighbours, of course, and so i want to be as soundproofed as possible, and my budget for the thing is $5000. (i work part time doing renovations, so can do much of it myself, and have access to free highly skilled labour as well, so the budget is only for materials)

So, my questions…

1. from my reading here I am leaning towards having just the concrete floor to see how that sounds. Correct?

2. After framing and insulating the exterior walls, should I put a layer of drywall, a gap, a drywall, framing with 4 inch soundproofing, drywall?

3. All the walls are unparallel, and there ceiling is sloped, these are good things, correct?

4. I can make a thick panel that can be placed over the window when needed, correct?

I hope this was all acceptably presented!

{EDIT - A year later…just to update the plan the 13.5x18.5 carport is now going to be the live room with vocal iso booth, with a control room and amp iso room in the basement beside it. Sketchups below}

Here it is.

Hi Martin, i'll try and shed some light on your questions and hopefully one of the 'gurus' will drop by at some point as well

Martin Tenbones wrote:I am putting the roof back on in a few days, but then am going to plan carefully how to finish the inside.

It might be a good idea to pause on reconstructing the roof, as you'll be able to easliy add materials for isolation before rebuilding it. Once the roof is on it becomes a whole other story. ( i learnt this the hard way and now have a triple leaf roof/ceiling in my studio which could have been avoided

Martin Tenbones wrote:we get a little loud, (whatever that means) but not extremely so

drums = loud. 100db+ even if you're not Van Halen

Martin Tenbones wrote: 1. from my reading here I am leaning towards having just the concrete floor to see how that sounds. Correct?

yep, best way to go.

Martin Tenbones wrote:2. After framing and insulating the exterior walls, should I put a layer of drywall, a gap, a drywall, framing with 4 inch soundproofing, drywall?

don't do that, that'll be a three leaf construction which is what you don't want. you say one of the exterior walls is cinder block, what are the rest of the exterior walls constructed of?

Using your cinder block wall as an example: The cinder block will be the outer leaf. You then only want one other wall, the inner leaf. Your construction from outside to inside would be, cinder block, air-gap (maybe 120mm) then your internal leaf timber/steel frame with all your drywall layers on one side of it, be that 1 layer, two layers etc etc. The air gap between the two leaves should be filled with loosly placed, uncompressed, fibreglass (30kg/m density) or rockwool (50kg/m density) in the cavity. If you construct the walls inside-out, ie: drywall facing the cinder block, you can then use the internal cavity to put acoustic treatment in as John suggests.

Martin Tenbones wrote: All the walls are unparallel, and there ceiling is sloped, these are good things, correct?

Room geometry isn't my strong point, but I think the ceiling may cause you issues as it looks to be sloped along the long axis of the room. ( i might be wrong, it's a bit hard to tell from the pic). You want your monitors firing along the long axis of the room once they're setup, which means you would have a different ceiling height and corner angle for either monitor. I believe that would be problematic as you want the room to be symetrical L/R and up/down (especially in front of you) as far as your listening position goes.

Martin Tenbones wrote: 4. I can make a thick panel that can be placed over the window when needed, correct?

If the window is in your outer leaf, then it'd be best to remove it and fill in with the same material as the external leaf is made of.

hope that's of some use to you and makes sense

steve

Thanks for the reply!

1. The roof. Well there's no way around it being a low slope roof attached to the side of the house, it will have 5/8 tongue and groove plywood on top of the joists and 2 layers of low slope roofing on it. This would be the outside leaf. The cavities would be filled with the appropriate insulation, then one maybe two layers of drywall on it for inside leaf. Correct?

2. I'm getting rid of the window.

3. For the 2 non cinder block exterior walls (the short walls), is 5/8 plywood sheeting alone ok for outer leaf? Those walls would be from outside to in 5/8 plywood - 2x6 wood frame with insulation - gap - 2x4 metal frame with insulation - 2 or 3 layers of drywall, correct?

4. What do you do about doors? My room has 3 at the moment.

5. I'm going to get on the drawings.

Martin Tenbones wrote: 1. The roof. Well there's no way around it being a low slope roof attached to the side of the house, it will have 5/8 tongue and groove plywood on top of the joists and 2 layers of low slope roofing on it. This would be the outside leaf. The cavities would be filled with the appropriate insulation, then one maybe two layers of drywall on it for inside leaf. Correct?

The plywood sounds good, but I'm not entirely sure what 'low slope' roofing material is.

Filling the cavity with insulation is the way to go. 30 kg/m for fibreglass, 50 for rockwool. Adding 1-2 layers of drywall to the underside is correct, but....to get the most sound isolation possible, building a room-within-a-room construction is the way to go. This means a seperate ceiling for your internal leaf that is not mechanically connected to your external leaf in any way (no screws, bolts, glue...nothing).

If you're buiding your internal walls as a second leaf and not mechanically attaching them to any of your external walls, then your internal ceiling will rest on these.

It's at about this point that you need to work out how much isolation you need by figuring out how loud you'll be at full noise, then figuring out how quiet you need it to be outside the studio to avoid complaints from neighbours etc. Subtract the small number from the big number and you get the transmission loss that you need to be aiming at with your build.

Martin Tenbones wrote:2. I'm getting rid of the window.

smart move.

Martin Tenbones wrote: For the 2 non cinder block exterior walls (the short walls), is 5/8 plywood sheeting alone ok for outer leaf?

It gets back to how much TL you need. But at a guess, that's nowhere near enough mass for one of your two leaves. To be honest, as soon as you've got drums in there the best way to go would be to rebuild those walls out of cinder block like the other wall.

Martin Tenbones wrote:Those walls would be from outside to in 5/8 plywood - 2x6 wood frame with insulation - gap - 2x4 metal frame with insulation - 2 or 3 layers of drywall, correct?

Construction wise that's right, but still, that 5/8 of plywood isn't buying you much in the isolation stakes.

Martin Tenbones wrote: 4. What do you do about doors? My room has 3 at the moment.

You have a door in each leaf. Each leaf is completely decoupled from the other and so to with the doors. This means you'll end up with six doors, all of which need to seal very, very well and be of similar density to the wall material of the leaf that they are in.

Martin Tenbones wrote:5. I'm going to get on the drawings.

yep, great idea that way we'll all know we're on the same page and any errors will be easy to spot.

steve

Thanks for the very helpful info! May I buy you an eBeer?

I am rebuilding the short walls anyway, so I will definitely do them with cinder block. That's cheaper than plywood as well!

Martin Tenbones wrote:Thanks for the very helpful info! May I buy you an eBeer?

i'll drop past next time i'm in Toronto and take you up on that offer

Martin Tenbones wrote:I am rebuilding the short walls anyway, so I will definitely do them with cinder block. That's cheaper than plywood as well!

nice one! And if you really wanted to get your isolation right up there you could core fill them with concrete. This would, however, require some really careful planning and consulting an enginner, along with serious foundations as the weight of the wall goes up astronomically. The wall would need to be reinforced with steel bar and you'd need a concrete pump to fill the wallls so it gets expensive real quick

If you don't core-fill (which is probably the more likely option) then make sure you do render the internal surface of the cinder blocks with a good solid coat of render. You'd be amazed at how much diference that will make! I can tell you it works from 1st hand experience.

steve

While I'm considering options, is there another acceptable outer leaf layer for exterior walls? Other than cinderblock?

Martin Tenbones wrote:While I'm considering options, is there another acceptable outer leaf layer for exterior walls? Other than cinderblock?

Basically, anything that is weather proof and airtight sealable is acceptable. After that it's about mass. Which is in turn about isolation. You could do a 1/4 inch thick cement sheet, seal it and you'd have an external leaf. You could also do a 2 ft thick conc wall and you'd have an external leaf. They'd both do the same job as an external leaf in regards to weather, but one would give you much, much more isolation.

The reason I suggested cinder-block is that you alrady have your long walls made of them, which means if you build the other two walls out of cinder block then you'll be getting them same level of isolation all round. (which would be quite good if done correctly).

So from here it's probably a matter of figuring how many dB of isolation you need, and then build accodingly.

cheers,

steve

i should also add: If you're rebuilding the walls out of cinder block you'll need to make sure you've got the right foundation under them. If the existing walls were timber frame only, then there's a pretty good chance that the slab may not be adequate to support a heavier wall. Get this checked out by an engineer or suitably qualified builder if you're unsure.

steve

Had slab checked out by masonary contractor. It too thin for cinderblock walls. The one cinderblock wall has some foundation below it. The rest does not.

Thinking of 3 layers of 1/2" cement board on the outside.

Martin Tenbones wrote:Had slab checked out by masonary contractor. It too thin for cinderblock walls. The one cinderblock wall has some foundation below it. The rest does not.

Thinking of 3 layers of 1/2" cement board on the outside.

good work having that checked out professionally, it could've been a nightmare if you hadn't.

3 layers of 1/2" cement board should give you some pretty good results. Make sure you seal any joins in each layer as you go so they're airtight.

OK, I've got a CAD program, and am working on my drawing.

Meantime, I'm wondering about HVAC. Can I use the existing run of duct from the house into the studio?

Thoughts?

Meantime, I'm wondering about HVAC. Can I use the existing run of duct from the house into the studio?

Possibly, possibly not... it all depends on if it was designed to handle the extra heat load and static pressure from the studio area. You'd have to get an HVAC guy to come in and check. The static pressure from the studio will be fairly high, probably (lots of distance to run), so take that into account.

Also, instead of your CAD program I'd really suggest using SketchUp. That's what we all use here on the forum, so its a lot easier for us to look at your model in detail, if you use it too.

- Stuart -

OK got Sketchup, figuring it out.