John Sayers' Recording Studio Design Forum Archive

ssl4000g wrote:Needless to say, I've reconsidered the whole project because of the radiant heat and the possible thermal loss. If this was easy, everybody'd be doing it!

What do you mean "possible thermal loss"? Are you referring to your radiant heat being less effective because of building over the concrete? If so, that will not be the case. Don't let this deter you! There are solutions. See if you can rent a thermal camera for an afternoon.

People do do it all the time. The radiant heat is not a big obstacle in my opinion. I'm very glad to have such efficient heating in my space. It's been awesome this winter so far, and I'm in Canada! Now figuring out all the details of this build and not screwing it up, that's a challenge! [/quote]

In thinking about the thermal loss, anything i put on top of the existing floor will have to be heated before the floor would become heated enough to radiate into the space. Therefore, it would seem likely that there would be an increase in the amount of time the heater would need to run, which would lead to increase heating costs and maintenance costs. It would also seem likely that the space would heat less efficiently especially in extreme situations such as multiple days that are significantly below freezing.

On the anchoring issue, after some further thought, while using fasteners and a glue solution, I would be concerned about the ability to de-anchoring a portion of the wall. This could be possible when; someone pushes a large amp cab into the room and it runs into the wall or, someone trips and fall into a wall... I know these sound a bit unlikely, but I've seen those things happen. I would point out that these walls carry the ceiling, so you have a load pressing down onto the walls. Should one of the walls become unanchored in a spot, the integrity of the box becomes compromised which could lead to collapse.

So, the heat int he floor coupled with the need to preserve the effectiveness of said heat, plus the need to support the inner structures seems to me to require careful consideration to undertake the best, most secure way of anchoring the walls. I don't have that solution yet. However, not considering the problem fully opens one up to serious problems should a wall become compromised.

Just food for thought colliderman. You have people in, you got to keep it safe. As we see so much in the studio biz, you do get what you pay for. I think that applies across the board to any aspect of studio business.

W

Hi Stuart,

I've been trying to figure out a way to isolate the control room as you suggested, but without losing too much floor space. I was reading this post on Soundproofing.com about adding staggered studs to an existing wall http://www.soundproofingcompany.com/sou ... stud-wall/.

What do you think about this plan? -

On three of the control room walls (all walls except the wall between the control room and live room) I would do staggered stud construction. I would build the left wall and front wall on top of the foundation footings so as to not lose any floor space. The footings are 8" wide and sit 10" proud above the concrete floor. The exterior walls sit on top of them, which are 2x6 framed walls. The footings are then insulated with 1.5" rigid insulation all the way around the inside perimeter. So on the inside of the exterior walls I have 2.5" of concrete footing that I could attach some furring strips to and then add staggered studs which my 2 layers of 5/8" drywall would attach to.

My questions are:

1) I know the isolation won't be as good as fully decoupled wall assemblies but could this be a reasonable alternative?

2) Should I use resilient channel with the staggered studs?

3) If I seal and caulk the drywall on the bottom of the footing, is the 1.5" of insulation ok to exist uncovered? (I would add trim to finish it). Or should I make it so the drywall extends the extra 10" down to the concrete floor? (There would be nothing securing the bottom 10" of drywall)

4) How does the ceiling assembly work with staggered wall construction? Can you point me to any information regarding this? I've been searching but haven't found much info.

Also, regarding building the new isolated live room ceiling below the existing drywalled ceiling you said -

You could do that. Yes, it would be a 3-leaf system, but you can compensate for that.

So you're saying that it's ok to frame and drywall the new ceiling underneath the existing drywall ceiling without removing the existing drywall or modifying that ceiling? Just want to be sure on that.
Could you explain what you mean by "you can compensate for that"?

Lastly, I borrowed an IR camera from work the other day to see if I could find the radiant heat tubing in the slab and..voila!! Worked like a charm! I could see all the lines in a fair bit of detail. So now I should be able to map out all the lines in the floor to make sure I don't puncture any when securing the base plates. Here are some photos of it -

Thanks again Stuart. I know you've got a million threads on the go and I really appreciate you taking the time to help us diy'ers.

I found the answer to the ceiling question in another post. Just wanted to post that here in case anyone else is wondering the same thing:

Yes it can work. Sometimes there is no choice but to do a 3-leaf, and even though the isolation is lower than for the equivalent 2-leaf, you can compensate for that with more mass and bigger air gaps. In your case, you would do that by putting drywall on the bottom of those joists to create the "middle" leaf, then building your rooms under that, and putting the final ceilings on as a third leaf. If you get enough mass and air gaps, then you can still get the isolation you want.

That quote is from this thread - http://www.johnlsayers.com/phpBB2/viewt ... =2&t=19691

As far as enough mass and air gaps, is 6.5" from the existing drywall to the new drywall enough air gap? (New joists 1" under existing ceiling, 2x6 new joists so 5.5" = 6.5" total.) Then for mass: 5/8" drywall -> green glue -> 5/8 drywall.

Thanks Stuart!

I've been trying to figure out a way to isolate the control room as you suggested, but without losing too much floor space. I was reading this post on Soundproofing.com about adding staggered studs to an existing wall

I guess it could work, but I'd like to see actual data on that method, from tests in an acoustic lab. I'd also like to see the opinion of some inspectors on whether or not it meets code.

It might be easier (and more effective) to use RSIC clips and hat channel.

1) I know the isolation won't be as good as fully decoupled wall assemblies but could this be a reasonable alternative?

Possibly, yes, but as I said, you'll never know unless it has been tested in a reputable acoustic lab.

2) Should I use resilient channel with the staggered studs?

Good question! Once again, you'd be your own guinea pig here, testing stuff that hasn't been tried and proven in a lab. In theory, it might work, but sometimes in practice there are effects that nobody considered, until the test data comes in and needs an explanation...

Or should I make it so the drywall extends the extra 10" down to the concrete floor? (There would be nothing securing the bottom 10" of drywall)

I would take it all the way down to the floor, and put a 1x1 furring strip on the floor, behind it, to attach the bottom edge to. Yes, that's a potential flanking path, but you can't just leave it floating and unsupported, and you also can't leave it hanging in mid air, 10" up.

4) How does the ceiling assembly work with staggered wall construction? Can you point me to any information regarding this? I've been searching but haven't found much info.

I don't normally do staggered-stud walls, so I can't tell you from experience, but what I probably would do is hang the inner-leaf joists from the original top plates, with joists hangers, then use RSIC clips and hat channel to decouple the drywall.

So you're saying that it's ok to frame and drywall the new ceiling underneath the existing drywall ceiling without removing the existing drywall or modifying that ceiling? Just want to be sure on that.
Could you explain what you mean by "you can compensate for that"?

Sometimes you have no choice but to create a three-leaf system, knowing that it won't be as good for low frequencies as a two-leaf system. When that happens, you can force the MSM resonance point back down again by putting more mass on the middle leaf and at least one other leaf, and/or by increasing the air gap between the middle leaf and the final leaf to something greater than what it would have been if it were only a two leaf system. The resonant frequency is governed mostly by tow factors: mass, and air gap. Increasing either of those forces the resonant frequency down lower.

Lastly, I borrowed an IR camera from work the other day to see if I could find the radiant heat tubing in the slab and..voila!! Worked like a charm! I could see all the lines in a fair bit of detail. So now I should be able to map out all the lines in the floor to make sure I don't puncture any when securing the base plates. Here are some photos of it -

Cool! Works great!

- Stuart -

Ok, I've alllllmost got it all figured out now..

There's just a couple construction details I'm still struggling with that are keeping me from finalizing this design.

1) Back to the ceiling.. Ok I think I get what you're saying, but bottom line, which one of these is the best method for isolation:

a. remove drywall on the existing ceiling, frame new rooms and ceiling joists, hang new drywall ceilings in new rooms (5/8" ->GG -> 5/8") and put a couple layers of insulation above them (as needed for thermal requirements as well as isolation).

b. Remove drywall on the existing ceiling, add new drywall or possibly plywood layers on top of those existing ceiling joists (creating an attic basically), frame new rooms and ceiling joists, hang new drywall ceilings in new rooms (same as option A)

c. Leave existing drywall ceiling as is, frame new rooms and ceiling joists a few inches underneath it, then drywall new ceilings as above.

2) Do I need to beef up the interior side of the roof, between the rafters, as I'm planning on doing to the exterior walls? Maybe this depends on the answer to the previous question..?

And lastly (and this is a big one!)

3) Exterior window construction!?! How to do this properly?! I'd like to have windows to the outside world where the current windows are. I know this is going to make isolation more difficult but there's no compromise on this, I want this studio to have windows! I live in a cold climate and all our windows are double paned with argon gas in between. This means having two of these windows (inner and outer leaf) will create 4 leaves. So what's the proper way to do this? Just use the thickest double pane windows I can get and create 4 leaves of glass? Or do I use only double pane on the exterior wall and single thick pane laminate glass on the interior? Won't this cause frost and moisture build up on the interior window, as well as still being 3 leaf? I can't seem to find any info about this or good studio build examples where they dealt with this problem. Please help!!

Thanks as always Stuart. I wish I could just hire you to design this!