John Sayers' Recording Studio Design Forum

Spans look good, that will support 40 psf live, 20 psf dead (good for 1-1/2" concrete +) so you should be good to go with exactly that last construction layout... Steve

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Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...

I didn't exactly draw it to scale. But the room is approx 17'x17' on the outside once I frame.

Also, on the floor, just for kicks, I took a piece of the 4" insulation I had, and set it down in the framing. It's a perfect size from the concrete to the top of the frame. Do I want the entire cavity filled, or should I go w/ the 3" and have a small air gap?

Thanks.

I would NOT put anything directly in contact with the concrete that doesn't HAVE to be - one way to handle this is to stretch chicken wire under the joists, leaving a gap wherever floating supports are - you can run the wire across several joists, pull it up on the outside of the last one, stretch it over the top of the last one and down the inside edge a ways, and fasten it there with long staples (staple gun) - then, at each joist along the way, at both edges of the wire, take some light galvanized wire (chicken wire is usually galvanized, so don't switch to copper or something - electrolysis will corrode the fasteners) - anyway, use some light wire (electric fence wire is ideal, you should be able to find a farm supply somewhere near Nashville) take a pair of pliers and bend a tight hook into one end of a 4" long piece of wire, reach down and hook one of the double twisted connections in the mesh of the chicken wire, pull it up against the side of the joist, and put a 9/16" staple across the short wire, about 1/2 way along its length. Then bend it down so it won't slide thru the staple, and staple the loose end. If you do this at each edge of each piece of chicken wire, and at the middle (if it's very wide, do it every 24")

What you want to end up with, is fairly tight stretched chicken wire across the bottoms of all your joists, for the insulation to rest on. This should keep it off the concrete enough to breathe, which is what you need to combat mold growth.

Now, at last; the answer to your actual question - I'd use the 3", read the above if you haven't already ... Steve

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Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...

Thought this might be a good place for this drawing for now... Steve

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Soooo, when a Musician dies, do they hear the white noise at the end of the tunnel??!? Hmmmm...

That's a good drawing there Steve. Beats using shims.

I would think that you could use "L" metal or something equiv. to it. Then you wouldn't have to weld or cut the metal.

That IS "L-metal", known in the trades as "angle iron" or just "angle" - I've not seen any ready-cut lengths that are heavy enough for floor support though, what I'd do here is cut the steel angle (comes in 20 foot lengths, most steel suppliers will cut it for you but more than one cut costs extra) -

the stuff I'd use (forgot to put it on the sketch) would be 1/4" thick walled 3"x3" or 3" x 2" steel angle, cut in 3" lengths so the mounting screws are far enough apart not to split the joists. I'd mount the levelers alternating on one side then the other of each joist, so twisting isn't a problem due to all the support points being on one side.

I would think that even if you had to have a fab shop make these they'd be cheaper than buying ready-made ones... Steve

Steve,

Just a quicky...you mentioned earlier in the thread to use "sill seal". I went to Home Depot to try and find "sill seal", and when I asked what it was, they just gave me a strage look.

I don't suppose you can give me a little better example?

Oh, by the way, I've been working on the plumbing issue. I'm ripping out all the old galvanized stuff and replacing w/ copper. In the process, I'll isolate the pipes. I already had the 1/8" rubber that I bought (thinking I was going to use it under the wall framing), so I bought brackets just a bit larger and placing the rubber on the inside of the bracket as well as up along the joists to isolate the pipes from touching the framing/joists. I think this will work out just fine.

Also, I look forward to helping/moderating on a new technical thread that John is going to post soon.

I'll be out of touch until 12/1 for Thanksgiving, then back to the grind. I guess this wasn't a quicky...LOL.

Thanks again,

Aaron

"sill seal" is (I think) a trade name, it's a thin closed cell foam strip, width of a 2x4 or 2x6, used to "bed" the perimeter sill plates of a house to prevent air infiltration thru irregularities between the concrete and the wood sill plate.

HD must be hiring McDonald's rejects now, for them not to be able to figure out from the freakin' NAME what it does, and what they have that's equivalent - Seriously, wouldn't you think that a person working in a building supply would need to know how to figure out what a customer wants? Nah, maybe not - I sometimes think you could tell a fast food employee to kiss your ass, and the answer would be "would you like fries with that?"

'Nuff rant for now, just ask the idiots at HD for whatever they sell to weatherseal between framing and concrete foundations - good luck.

If you have any of the 1/8" rubber left, that will work also. It's just when you start getting thicker that you run the risk of finding that the resonant frequency of the isolator is the same as that of the wall, which is NO good... Steve

I've got plenty of the 1/8" rubber. I bought a 1/8"x4"x50 feet. And at almost a buck a foot, it would be nice to use it somewhere. So the 1/8" would be ok to use for this? My thoughts behind it was to help "float" the walls, but in the earlier diagrams, you recommended not using it.

I think I know what you're talking about as far as the pink stuff. Doesn't it come if 4'x8' sheets usually? Some people use it in walls, or between floor joists? Is this the same stuff or is it too squishy and compact too much? Or am I completely on the wrong thought here?

As far as HD...don't know. Some of them are quite helpful, but then again when I tell people what my uses are for some of these materials, they haven't a clue. I would think that for as many studios that have been built here in Nashville, they would know a little more. But, then again, I'm sure turnover is high and all young blood without the knowledge. The old timers are helpful though.

Thanks,

Aaron

That sounds like the same stuff - Michael Jones first mentioned it to me, I've not built much from scratch outside since stiffer requirements for energy were implemented - his came in narrow rolls, specifically for using under sill plates. All you need is for it to fill in cracks and prevent rattles/vibrations, so excessive thickness isn't necessary.

Know what you mean about HD help - there are 2 or 3 guys at my local HD that actually are helpful - at least two of them are former contractors, so no surprise that they know what's what. I don't think HD is any different than any other company, in that training isn't a very high priority if they can skate by without it. So you can only hope you get someone with enough of an interest to learn on their own.

You're right, I do recommend not "floating" walls - the exception to that is RC on one of the two leaves. I may have missed that yours was only 1/8", or there may have been another reason - last count I'd posted 1,212 answers since March, so might not remember everything I've said so far -

Generally, if a wall isn't going to rattle for any reason, then all you need is to caulk each layer of wall paneling on each side as you go. Using separate frames, you don't need RC, but if the inner frame is floated on a floating floor, there may be some advantage to putting rubber under that frame so that the floor, walls, and ceiling all maintain their own vibration characteristics. Connection between the wall surfaces and floor/ceiling surfaces should only be flexible caulk. Using single frames (if both sides have paneling because it's the ONLY wall) then you DO need RC for best isolation. In ANY case, spacing the wallboard away from adjoining surfaces by 1/4" and filling with acoustic caulk gives best isolation.

Looking forward to your Forum - not sure what your electrical background is, but we can discuss that in the Engine room or PM if you like... Steve

Steve,

Just for curiosity, and I think I already know the answer. In reference to RC, it is suggested or recommended that if you have two walls (the one on the inside of the control room, and the second on the studio side) you should only have RC on only one of the two walls. Is this correct? I'm assuming this is so that each wall has different characteristics.

Also, in reference to stud spacing, I've read the pluses and minuses to the acoustical properties of both 16 & 24" OC spacing. Would it be benificial on a double wall scenario to make one wall 24" OC and the other 16" OC? Or should they both be the same?

Thanks,

Aaron

The main reason for only using RC on one side of a single framed wall is so that one leaf of the wall retains some stiffness, which improves bass TL - on a double framed wall, same thing - a stiffer wall and a floppier wall will exhibit different tendencies all around, so will complement each other. I've not tried this, but from my info so far it looks like a good way to build double framed walls would be to put the heavier mass leaf on 16" centers for a stiff leaf, then use the lighter mass on 24" centers with the second studs in each wall offset by 4" - that way, no two studs are coincident, so each wall panel would have a stud somewhere opposite its more flexible section, which would stiffen that opposite panel against transfer somewhat.

Double framed walls need no resilient channel for really good isolation - it doesn't hurt, though, if one of the frames is resting on a separate, floated floor. If both are done that way, each on its own floor, even better.

From calculations I've done, if you're willing to put a couple extra layers of wallboard on one leaf of a wall, you can gain some extra bass trapping on the OTHER leaf by using only a single panel on 24" centers, which will give you your air space between leafs AND act as a panel trap. The distance between leaves and the mass of the panel determines the peak frequency affected, but ranges down to 30 hZ are possible if you're willing to give up 1-2 dB of STC AND about 8-10 inches of space total between panels.

Here's an example of what I mean - don't have my laptop handy with all my calc tools, but resonance on the trap as described would be maybe 40 hZ or thereabouts... Steve

Hmmm...

So if I were to do this, there would only be one layer of drywall on the interior wall for the control room? That doesn't seem as though it would give me much isolation from upstairs at that point. Plus I would then have to layer everywall in the rest of the studio w/ at least 4 layers of drywall. (Only one wall in most area's - around perimeter of basement) There is about 4 1/2" of space between the concrete block and where any wall framing or floating floor framing will be. (termite shield to get around).


Thanks.

You're right about the upstairs isolation thing, forgot where you were building momentarily. In that case, you'd need to go back to more balanced (but not totally balanced) leaves, otherwise the upstairs noise would end up behind only ONE layer of wallboard - looks like you'll need a bit more bass trapping from other sources, but if isolation from upstairs is a problem (and you can't put a couple more layers on your upstairs floor) then the more balanced wall construction will be necessary.

See, those things are tasting more like rabbit pellets every day (If that punch line's too old for you to remember, don't ask) ... Steve

Steve,

On page 4 of this thread, I posted a drawing on wall/ceiling construction. At the top of this page, you said it all looks fine.

Let me throw a monkey wrench in here...(I can't draw it since my program expired-you'll have to refer to the other drawing)...OK, Joists, RC, 2 layers of 5/8" drywall, then I have the framing for control room ceiling resting on the walls, and RC, then 2 more layers of 5/8" or a mixture of 5/8, 3/8, 1/2 coming down on the inside of the walls.

Should I be ok for this? If I'm placing 3 layers of drywall, what should I space the RC out to? 16", 12", 20", etc.?

Thanks,

Aaron