Planning design of a full recording studio/ Now building...

Well it's been a long time since my last post. I have finally settle to go on with my last drawing.For reference you can have a check there. http://www.johnlsayers.com/phpBB2/viewtopic.php?t=5593 .Lots of things have been done since then .I have been very very busy lately. I'll post lots of pictures soon. As we speak all the control room walls are up on a U-Boats floated floor. I am now in the process of adding layers on those new walls. Here's how everything is done so far. My floor is made of 2X3 joist floated on U-Boats at evey 12" at the perimeter and 16"o.c. for the inner surface. All cavities filled with Roxul Safe'n sound.And to top it all ,one layer of 5/8plywood so far, more later. My walls are made of 2X4 studs at 24"o.c. filled with 3" Roxul Safe'n sound, as we speak they are covered by one layer of 5/8 gypsum board caulked at their perimeter (using the foambacked rod technique). The walls are resting on Etafoam (thermal isolation product, i did not used that as a decoupler but rather as a sealer) , and screwed to the floor. All walls framing are not touching each other, and gypsum leaves are not touching adjecent walls or ceilling or floor. The walls are held in place using a DIY bracket made of steel and EPDM rubber (photos to come).There is a 3/8 space between the top of the walls and the actual ceiling. Good job so far but now i am facing a new questions that keeps me awake at night ':shock:'. How in Hell will i make my angled ceilling hold in place ? see fig.A below. The actual ceiling is 8mm(1/2) gypsum board fixed on forens at every 16"o.c. wich is nailed diretcly on the Roof joist. i didn't want to take off the gypsum board because it keeps rodents that gets in the attic from getting in ! ( i am not talking of one or two...). And i do have some concern about adding weight to the existing ceilling. Well i am stuck, i really need some advise here on how to make this ceiling, without compromising what i have already done. Fig.A.

Eric, sorry for the delay; can you show your roof frame and give measurements for all the lumber dimensions, etc? Include board size, spacing, unsupported lengths, and how the rest of the building ties in with what you've already shown- thanks... Steve BTW, 8mm is just under 3/8" - 12.5mm is closer to half inch.

Hi Knightfly Glad to hear from you ! It's been a while since our last chat. Well here's a graph with all the info you asked for (i hope). BTW When you read "Real" 2X6 or 2X4 it just mean that it is their real dimension, they really do make 2" by 6" and not 1 1/2 by 5 5/8 for example.The graph is not to scale. You may also check a new thread i have started about ceilling design in wich i describe two options, i would do the first one . here's the link http://www.johnlsayers.com/phpBB2/viewtopic.php?t=6936 Regards

OK, and you're wanting to put a slanted ceiling INSIDE all that? Or is the drawing already including your inner ceiling, but not shown with a slant? Steve

Sorry, i was'nt clear in my last post. The graph shows what i have now. i want to built a slanted ceilling inside of that, and i have concerned about putting more weight on the building structure and this mices problem i have. I thought to attached the ceiliing to the two side walls and decoupling it in some manner. As for my mices problem, please don't askme to call an exterminator, cause it would only be a temporary solution, i am still in the process of finding and fixing all the tiny holes and gap by wich they get in. That of course was already done behind the control room walls already in place. I would also add that i don't think i 'll be able to keep them from reaching the attic. that is the reason i have left the 1/2 gysum board on the ceilling bulding. i know this is not "the way to go" but i guess i'll have to compromise. If you have better ideas please share. When i bought my house two years ago i have seen what those little things do to insulation in my basement and belive me you don't want that. I understand you've been very busy lately, i really do appreciate your time and feedback. Keep it up Regards

I know all about rodent infestations, wifey decided a few years back that she wanted rabbit manure "for the garden", then decided she wanted 'em to have an un-caged "run around" area, which led to a raised "4-plex", which led to a self-feeder, which led to a MAJOR wood-rat infestation, which led to me moving the rabbits out of the area, spraying volatile carburetor cleaner into the holes, lighting it with a propane torch and shooting everything that ran out with a pistol filled with "snake loads" - killed about 25 full-grown adult rats (approx. 6-7" long body) and another 25-30 "adolescents" (3-5" body) Never did get any manure for the garden, kinda hard to sift those little pellets out of freakin' GRASS :roll: So, are we still talking about your same design? If so, aren't you doing separate inner wall frames? And if so, why can't you support a ceiling frame on your inner wall frames? For example, in the CR you'd want a sturdy header across the two widest points, then slope the rafters up from front to the header and back down to the two rear walls... Steve

Man ! must have been funny watching you rat hunting, but your rodent probs were probably worst than mine, I only have mices, zillions of mices, and no matter how many poison traps and mouse traps I put, those pesky kindacute “squaters” still don’t get that I’m the one who pays the mortgage :lol: by chance I don’t have bear size rats !! :shock:

So, are we still talking about your same design?

Yes.

if so, aren't you doing separate inner wall frames?

Of course.

And if so, why can't you support a ceiling frame on your inner wall frames??

Well, obviously I though about that. I know I don’t have much choices by now but woudn’t I compromise some performance doing it like that ? And is it a good idea in the first place to do a sloped ceiling in gypsum, or should I go the more traditional way and I built a flat cellling lower than the actual building ceiling, then put hangers then built a sloped false ceiling. I’m just lost. I guess the correct question would be : What would you do ? BTW I have ordered Rod’s book, so questions like the ones above will likely be no more to your great pleasure. Thank you for your patience. As a bonus, here’s some picture of my work so far. Sorry for some reason comments don't appear in each pict so here you go : DSC1-My brother removing the load bearing wall. DSC2-The wall is no more...and the building is still standing. OK DO NOT DO THIS unless you know wht you are doing some reinforcement where necessary and everything was done safely and approved. DSC3-moving the entry door DSC00008-this was my first location for the studio but the owner obviously, was not so please with the idea :wink: DSC5-This is where the CR is gonna be DSC6-Framing the floor

more pix DSC6-Framing done DSC7-Each EPDM rubber pad placed every 16"along floor joists are glued to the wood plate using high quality silicone. Each wood plate used as shims and support is glued to the joists using Bulldog grip Premium PL Glue. DSC8-Three walls up... two to go. DSC9-First side wall. WHat a mess... :oops: DSC10-Adding insulation and vapor barrier. DSC11-Adding first layer of 5/8 gypsum

even more pix DSC12-Floor corner detail DSC13-U-Boats every 12" on wall perimeter. DSC14-Another view of the front wall U-Boats set-up (Need a little clean up...) DSC15-Front wall with insulation, notice the square in the middle where the CR window is gonna be. DSC16-One of the two side wall, with the window ready to be cut-out. DSC17-Easy bracket using EPDM rubber,silicone and steel corner

bracket in place

Question, How big of a difference does the vapor barrier make? Is it part of the "air-tight" concept, or more of an environmental thing? Looks great! Ben

The vapor barrier is not part of the "air tight" concept. But rather part of the thermal insulation concept. Only used on external walls and depending on your location it goes to different place in the wall and it is needed to protect internal wall structure form moisture and mold developement. Here in Montreal the vapor barrier is always placed on the hot side of insulation. It is NOT to be overlooked. In a studio construction concept, care must be taken to make sure the barrier does not compromise the double partition wall concept by placing it, say between the two walls, thus creating a third partition and compromising the "Mass air Mass" system. Air must move freely between the two walls. Hope this clear things up a bit. Regards

I've skimmed this thread and the one linked from the first post, but I don't seem to find any information about why you decided to float your rooms. It appears you're using rather thin EPDM pieces as your elastomers, including the Auralex U-boats. Have you done any calculations to ensure that you're not overloading or underloading the rubber? Also, your floor seems rather thin. I'm concerned that your resonance frequency will actually amplify the sound, not reduce it as you are hoping. I fear that you may be spending a lot of money and time on a solution that will perform worse than if you had not floated at all... :roll: I sincerely hope that is not the case. --Keith :mrgreen:

Hi Keith, glad to hear from someone, the group is getting very quiet these days.

I've skimmed this thread and the one linked from the first post, but I don't seem to find any information about why you decided to float your rooms.

Mainly because all of the other rooms won’t be floated, just the CR. And I had to do a false floor anyway because the concrete slab was not leveled right in this part of the building, almost 2” difference between the back of the CR corner and the left front wall corner. But I could have poured a new leveled layer of concrete and build directly on top of that, see budget is the key word here… and now as I see it, budget and studio construction just can’t go in the same sentence. :wink:

It appears you're using rather thin EPDM pieces as your elastomers, including the Auralex U-boats.

EPDM rubber piece thickness vary between ½” and 5/8”. Ain’t that enough ? borderline I admit, I had them very cheap including the u-boats.

Have you done any calculations to ensure that you're not overloading or underloading the rubber?

Yes I did and I should end up close to the optimum compression ration, I don’t have the numbers handy (this place is a mess). But I can post them when I found them, if you like.

Also, your floor seems rather thin. I'm concerned that your resonance frequency will actually amplify the sound, not reduce it as you are hoping.

Good point, but the photos are not up to date.There is insulation between every joist of the floor. As we speak there is an additional layer of ¾” MDF boards and I’ll probably add some more later and there will be an hardwood floor on top of that. I know that mass is a key point here.

I fear that you may be spending a lot of money and time on a solution that will perform worse than if you had not floated at all... I sincerely hope that is not the case.

Well, thanks for your concern, I certainly hope it is not the case too. But now you put doubt in my mind, and I had a very bad night sleep. :? On the other hand even if it is not perfect, wich I doubt it will be anyway, it just can’t be worse than what I had before, I ‘ve mixed albums in real studios AND most of the time, in living rooms with cool looking foams on walls, In very small rooms like 9X10 wich sounded awfull, in unfinished basement…name it. I had to double check everything I did in those places, and I always ended up knowing the “signature” of a particular room. My point is I don’t belive in the perfect CR, every studios I went to have their own sonic character, a pleasant one I admit, but I was not “flat”. There is just too many variable in the equation to my humble opinion, but what do I know…I just talk too much. That being said, if I can do it as close as it should be and avoid some error in the process, I will. So if you feel something is wrong with what I’m doing, please share, I am more than open to here from you. Regards

orangenumerik wrote:

sharward wrote:

I've skimmed this thread and the one linked from the first post, but I don't seem to find any information about why you decided to float your rooms.

Mainly because all of the other rooms won’t be floated, just the CR. And I had to do a false floor anyway because the concrete slab was not leveled right in this part of the building, almost 2” difference between the back of the CR corner and the left front wall corner. . .

Ah, OK. That makes sense.

orangenumerik wrote:

EPDM rubber piece thickness vary between ½” and 5/8”. Ain’t that enough ? borderline I admit, I had them very cheap including the u-boats.

I don't know... :roll: ...That seems pretty thin to me. As far as the U-boats are concerned, see this thread, including the link to the manufacturer's document, which includes a link to a page on their site that states they have done no testing on them. :evil:

orangenumerik wrote:

sharward wrote:

Have you done any calculations to ensure that you're not overloading or underloading the rubber?

Yes I did and I should end up close to the optimum compression ration, I don’t have the numbers handy (this place is a mess). But I can post them when I found them, if you like.

Yeah, it would be good to see that if you can locate them. We need to emphasize to everyone who comes across this thread the importance of doing those calculations. :-)

orangenumerik wrote:

. . . the photos are not up to date.There is insulation between every joist of the floor. As we speak there is an additional layer of ¾” MDF boards and I’ll probably add some more later and there will be an hardwood floor on top of that. I know that mass is a key point here.

Hopefully that will be enough mass... At least this isn't for a live room where the sound levels would be a lot higher than in a control room. --Keith :mrgreen:

Eric, I'm just now getting the chance to really read your thread here (after replying to your PM). I don't have the opportunity during the day anymore to really read through much. Looking at your floor construction, I do have one question since your picture doesn't really show much. How many stringers do you have and how far apart are they between the main studs/joists? I had one corner that I spaced them a little too far apart, and it gave some resonant frequency. (fortunately it was under the bass trap I have in the corner, but when I stomped on the floor, it was evident with a "boom".) This also gives stability to your floor. Without them, you may risk the chance of collapse. In reference to your angled ceiling question, Are you building any type of traps or structures inside of your shell? If so, you can reference my thread (I don't know what page) that shows how I angled for acoustic treatment. My shell (ceiling in this case) is attached to RC on the joists (flat ceiling). In reference to your ceiling, what is the span of your joists, and where are your supports? And are they all 2x6 or larger? Is there a reason why you can not remove the existing drywall from your ceiling, or can you just add an additional layer to it?

Hi Aaronw, glad to hear from you, i got all your post, i am somewhat restricted as far as reading my post during the day too.

Are your walls currently attached to the ceiling? Or are they floating in air?

No floating in air here :wink: They are holding in place using isolated DIY brackets attached to the ceiling

What are your acoustic intentions for the ceiling?

This is what all these post are about for a month… I don’t know… what I should do. The ceiling thing seems to me as an info black hole as how to do it and what are the options.

Looking at your floor construction, I do have one question since your picture doesn't really show much. How many stringers do you have and how far apart are they between the main studs/joists?

One every 48” o.c.

I had one corner that I spaced them a little too far apart, and it gave some resonant frequency. (fortunately it was under the bass trap I have in the corner, but when I stomped on the floor, it was evident with a "boom".)

Humm sounds like something i know... :?

In reference to your angled ceiling question, Are you building any type of traps or structures inside of your shell?

Yes I will. I plan to do one Big bass trap (3' deep) in the back corner, two others behind the monitors (I don't think i'll go for a soffit design, not sure) Slats resonator on the side walls, Hi freq absorber/low mid absorber an the rear walls. But i'll see as i go. Just for the fun of it i did a listening test with the room naked and it really sounded like crap :wink: . I have cancellation in the lows, huge bump around 500hz, bump around 200hz a little too much around 6Khz, no imaging at all. I didn't expect it to be great sounding...but not that bad. I don't even recognised my E8, they now sounded more like some auratone or some cheap 4" speakers.

In reference to your ceiling, what is the span of your joists, and where are your supports? And are they all 2x6 or larger?

Joist span of ceiling 24” o.c. with perpendicular forens every 16” o.c. they are all 2X6. with a total span width of 25’ supported only by their edges. Don’t forget that winter is a real nightmare here, I had no less than 4feet of snow and ice last winter. That is why I do not want too much weight to the actual ceiling.

Is there a reason why you can not remove the existing drywall from your ceiling, or can you just add an additional layer to it?

Well from a design point of view and to keep the Mass Air Mass thing happening I need to leave the gypsum on the building ceiling there. See there is no floor on top of that ceiling. If I remove the gypsum and build a new ceiling underneath I’ll end up with Mass Air and…well Air ! Just see it as an “inverted” design. Also I have a rodent problem, leaving the gypsum there keep them from getting in.. My problem is not there, it is, wich ceiling design should I choose for my situation : Gypsum slanted then acousticly treated ? or Gypsum flat then false slanted cloud ceiling ? or Gypsum flat then hangers hidden by false ceiling? Wich is best ? are there other option ? Then whichever design I choose, how should I make it hold in place ? Thanks for your reply I really appreciate. Regards

Here's what I did to make the false ceiling, and how it's attached... http://www.johnlsayers.com/phpBB2/viewt ... &start=422

Hi Aaronw OK, so you have made your inner shell, drop your ceiling from resilient channel attached to floor joist. then ran a false ceiling of 703 below it right ? (Great job BTW) Is your false ceiling slanted (it's hard to tell from the photos) ? And one more tricky question, if you had a 9 foot ceiling height would you have done the same ceiling design ? Regards

Is your false ceiling slanted (it's hard to tell from the photos) ?

It is slanted.

And one more tricky question, if you had a 9 foot ceiling height would you have done the same ceiling design ?

I would have done some similar things. I have a steel beam in the middle that I have to work around. If I had 12 ft ceilings, I would add vertical bass hangers and an angled ceiling.

So here’s a graph of my projected “shell” CR ceiling. Made according to recommendation from users of this fantastic forum. To keep the graph clear I didn’t include the walls frame but only the 4 support posts for the ceiling joist already built into the walls. The two big 2X8 joists would be screwed in place using standard U shaped bracket used in floor construction (I don’t know the English word for it) as would all the 2X4 joists. I know this is probably not the best way to go, but as I previously said all my walls are up with 2 layers of gypsum boards and the walls top plate are just under 3/8 of the building ceiling. If any of you gurus out there have a better idea, please share… What is not shown on the graph are the resilient channels that would be running perpendicular to the 2X4 joist every 16” o.c., and the 2 layer of 5/8 gypsum sealed at their perimeters. All the ceiling cavities would be filled with 3”rockwool. The air space between the new ceiling and the existing one would be 10 ¾”. That would leave me with 8’9” as total and usable ceiling height for the CR. So I can run a false “cloud” ceiling starting around 7’9”front and up to 8’9”. Giving me a variable air space between the false ceiling and the “shell” ceiling. :) Some questions : What would be the acoustic incidence of having ceiling support attached to the walls instead of resting on the walls frame’s top plates ? Is 24” o.c. ok for a ceiling ? I made some weight calculation and the whole ceiling including the frame and rockwool should weight around 1350lbs. If my calculation were right it means less than 12lbs per linear foot. As I said i am going to build a false slanted ceiling underneath that. For the lower section of the false ceiling, near the front of the CR can I use the frame structure of the future corners bass traps as support? Still concerning the false ceiling can I screw though the CR “shell“ceiling and use the big central 2X8 joist as support to hang it in the higher section ? So what do you guys think...am I “shopping” for a disaster ? :? Cloud shoveling ? Daydreaming…? Thanks to all

Hello Eric,

Is 24” o.c. ok for a ceiling ? I made some weight calculation and the whole ceiling including the frame and rockwool should weight around 1350lbs. If my calculation were right it means less than 12lbs per linear foot.

I'm not a structural engineer, but hanging 1350 lbs over your head, I would probably do 16" OC.

Still concerning the false ceiling can I screw though the CR “shell“ceiling and use the big central 2X8 joist as support to hang it in the higher section ?

What is the construction materials for the false ceiling? In reference to your new ceiling joists, any reason you're using 2x4's instead of the 2x8's you're using for the beam? Is it a height issue with the angle?

The weight per linear foot is less important than the maximum weight that the lumber can carry based on the overall span. Have you done any span calculatiions? :roll: When it comes to keeping yourself and others unflattened, don't assume anything. ;-) --Keith :mrgreen:

U shaped bracket used in floor construction (I don’t know the English word for it)

I think you mean a Joist Hanger. I think 2x4's can only span 6' or less as joist. Check out the span calculator Sharward linked to and I'm pretty sure you're going to have to switch to 2x6 for ceiling joists. Allowable 2x6 span is 11 or 12 feet or more... depending on the grade and species of wood. You'll need to check out the load for your middle 2x8 joist too, or maybe even come up with another ceiling plan. BTW your not the only one on this forum to make a plan using 2x4's for a longer then allowable joist span, I can think of at least 2 others, myself included. :roll: Marc :twisted:

Thanks so much guys ! That is why i love this place so much. Aaronw

What is the construction materials for the false ceiling?

Not decided yet but it will be a lightweight structures with rockwool and fabric and some light fixtures. Thanks to Sharward for the span calculator this is exacly what i was looking for. Maybe you can help me with that , what is the deflection limit factor in the calculator. and i am also not sure about the live and dead load thing...but i know how to mix 100 tracks in 5.1 ! :lol: Sharward

When it comes to keeping yourself and others unflattened, don't assume anything.

Right, like one of my friend always says "assumption is the mother of all F***k-up". Let's just say i don't assume i am verifying with the experts :wink: guitardad

I think you mean a Joist Hanger.

Ha that's the word for it, so simple. You don't want to know how we call that in french ! guitardad

You'll need to check out the load for your middle 2x8 joist too, or maybe even come up with another ceiling plan.

I'll do the math. But my plan was to reinforced that joist with 3/4 plywood glued and screwed on each side all along the joist. But i can always use a bigger one. guitardad

BTW your not the only one on this forum to make a plan using 2x4's for a longer then allowable joist span, I can think of at least 2 others, myself included.

OK i feel good about myself now. :) Thanks to all