recording studio in germany - need some advice

i saw that picture (besides others) in your thread, sharward, that we read several times, i think :-) and we read through the reference-section quite a lot before the confusion starts again here (i think most of the time the confusion starts, because we are not native english speakers and from time to time we maybe don`t get the subtleties in some of the sentences all of you are writing), i have to ask a plain question, i asked some posts ago. we thought, we HAD to build an inside-out-.wall because that seemd to be for us the way to go. then we would have a conrete wall AND a inner wall (inside-out) that makes two leafs. now it seems we have the conrete wall and a normal double framed construction (as steve pointed out), for me that makes again three leafs. but as rod pointed out, sometimes you have to go with three leafs. and if read through steves last post (maybe i get it wrong again)....

Where you have adequate space for walls, normal double framed construction is more practical. It just takes a bit more lumber if you're treating the inner walls... Steve

i don`t think he was talking ybout a double-framed wall with gypsum on both sides as said we would just need "more lumber" oppposed to our inital plan to build the inside out wall with an air/space inside room which already has conrete walls as existing walls. (i hope that he would have mentioned the "little bit mor gypsum" we would need if we build a functionally two-leaf, double-framed wall next to the conrete wall so my question, and i hope, that will clarify the confusion: should we really do something like in the sketch you just posted, having in mind that we already have a conrete wall as outer leaf? that would make a conrete wall AND a two-leaf, double-framed wall we understood the principle of a two-leaf, double-framed wall already. we are just a little bit confused how to bring the already existing concrete wall into the game as most of the threads about that subject have the basis that there is already an existing outer wall that is build almost the same way as a inner wooden frame would be build (i guess the american/english way) as opposed to our conrete outer wall (we don`t have wooden framed walls here in germany a lot) i looked at your pics a lot http://www.johnlsayers.com/phpBB2/viewt ... &start=300 http://www.johnlsayers.com/phpBB2/viewt ... &start=345 and there you deal with a two-leaf, double-framed wall because you are using one already existing woodenframe as one of the leafs (i know we have to use that principle for the separation between CR and tracking room, cause theres is just a penetrated concrete wall and for the holes there we have to use a two-leaf, double-framed wall ) thanx jens&elis

themHorses wrote:

. . . i think most of the time the confusion starts, because we are not native english speakers and from time to time we maybe don`t get the subtleties in some of the sentences all of you are writing . . .

Well you write English beautifully 8) -- much better than I can do auf Deutsch (and I can, a little, nur ein Bischen :roll:).

now it seems we have the conrete wall and a normal double framed construction (as steve pointed out), for me that makes again three leafs.

Right. That's not good. :roll:

but as rod pointed out, sometimes you have to go with three leafs.

I don't think you'll have to though. Usually one has to go with three leaves when one already has two leaves and must add one.

should we really do something like in the sketch you just posted, having in mind that we already have a conrete wall as outer leaf? that would make a conrete wall AND a two-leaf, double-framed wall[/b]

No. Not ideally.

we are just a little bit confused how to bring the already existing concrete wall into the game as most of the threads about that subject have the basis that there is already an existing outer wall that is build almost the same way as a inner wooden frame would be build (i guess the american/english way) as opposed to our conrete outer wall

OK, I think I understand your situation better now. Tell us more about your exterior wall. Is it concrete block? If so, are the blocks filled with anything? I believe the answer to this question will determine the direction you'll need to go. Tschuß! --Keith :mrgreen:

Sorry for the confusion of terms; by "double framed wall" in this case, I meant your existing concrete and a second leaf, held up by a separate frame - in other words, a 2-leaf wall. Which side of that leaf the frame goes on will not change the TL of that wall, unless the position of the second mass (all layers of paneling mounted to the new frame) changes relative to the concrete. By this I mean - same air gap, same TL. If you intend a 500mm air space, there is only one MINOR reason for building the new wall "inside out" - that is a slight savings in lumber cost by not needing lumber on BOTH sides of the gypsum panels. The downside of "inside out" is trying to build the entire wall and THEN tipping it into place without a CRANE or 12 strong men to help - it also makes mounting of IN-wall insulation (necessary for damping and several dB of TL) very difficult. Keith brings up another valid question about your concrete walls - hollow block already act as a 2-leaf wall, so it would help if you know whether your concrete is solid or hollow block, or?? Steve

as always: thanks for your quick responses @keith: thanks for encouragement concerning my english :oops: but we should write in german, cause it seems your german is much better than my english: hallo keith, alles klar bei dir? wie geht es so? :D ok, now we cleared the confusion a little bit we feel a little bit wiser. we surely have to find out about our concrete wall in terms of which material has been used to build it. we should have a meeting with the landlord and his engineer next week or so. but in the meantime i assume that it is a solid wall like most of the walls here are build.

If you intend a 500mm air space, there is only one MINOR reason for building the new wall "inside out" - that is a slight savings in lumber cost by not needing lumber on BOTH sides of the gypsum panels. .

and there we go again with confusion. :roll: steve, when your are talking about the normal two framed (NOT TWO LEAF) system, are you talking of something like this. or is the second frame just there to hold up the whole system? (and we really thought we got it, even with our existing wall)?

themHorses wrote:

. . . we should write in german, cause it seems your german is much better than my english: hallo keith, alles klar bei dir? wie geht es so? :D

Ich habe nur drei Jahre in die Schule gelernt; Ich verstehe nur ein Bischen -- das ist ein gut idee nicht! ;) (For those who know no German, I just told and proved to our friend that I suck at German, so that should put it to an end! ;-) )

steve, when your are talking about the normal two framed (NOT TWO LEAF) system, are you talking of something like this. or is the second frame just there to hold up the whole system? (and we really thought we got it, even with our existing wall)?

That is what he is not saying. To keep it simple, you do not need to do an inside-out wall. You should build a normal wall with insulation behind it. After construction is complete, you can treat the walls inside the rooms for acoustic purposes. --Keith :mrgreen:

thanks again for the answer and lets stop the german for now :-)

To keep it simple, you do not need to do an inside-out wall. You should build a normal wall with insulation behind it. After construction is complete, you can treat the walls inside the rooms for acoustic purposes.

ok i think with your (keith) and steves answer i can combine the right way. the confusion arose about that sentence from steve where he was pointing out that we wold need "additional" lumber for a normal wall. what i understand now is that we would build the inner leaf like this (from the outside to the inside): - wooden frame filled with insulation) - three layers gypsum - wooden frame to treat the wall acoustically so the second frame is not for soundproofing but for acoustical treatment because we have the blank gypsum now pointing TO our room am i right, am i wrong, am i right, am i wrong? one more question. i read a lot of threads to find what sizes your studs are and found a lot of different suggestions including the wrintings of john at sae, where he is talking about 75x35mm studs. i know it depends on our total weight. but if we`d use three layers of 15mm gypsum and a ceiling that is rested on that inner frame i think that size would do well. am i right, am i wrong, am i right, am i wrong? as always: appreciating your answers btw: that truck looks nice in front of your house, keith :D i wish we would have settled everything with our potential landlord already greetings from berlin in germany jens[/quote]

themHorses wrote:

what i understand now is that we would build the inner leaf like this (from the outside to the inside): - wooden frame filled with insulation) - three layers gypsum - wooden frame to treat the wall acoustically so the second frame is not for soundproofing but for acoustical treatment because we have the blank gypsum now pointing TO our room am i right, am i wrong, am i right, am i wrong?

Correct. However, I would like to clarify something. In English we refer to "framing" as the lumber used to build walls, floors, ceilings, etc. -- like this. We also use the word "framing" to describe what goes around a picture that hangs on a wall -- like this. We sometimes describe the process of building acoustic treatments/traps added to walls, visible inside the room, as "building frames and putting insulation in them," just like what was done on this page, and then hanging it on a wall just like a picture or a piece of artwork. If auf Deutsch there are different words to describe these different things, then no wonder you're confused! :shock: So, yes, you will use lumber to frame a wall structure ("framing the wall") and put multiple layers of gypsum on it, and then probably frame acoustic treatments and attach them to the finished wall. I want to make sure that you understand we are not talking about building "two wall frames."

one more question. i read a lot of threads to find what sizes your studs are and found a lot of different suggestions including the wrintings of john at sae, where he is talking about 75x35mm studs. i know it depends on our total weight. but if we`d use three layers of 15mm gypsum and a ceiling that is rested on that inner frame i think that size would do well.

I think 75mm may be too small for 3 layers of gypsum. I think 135mm would be better. (I'm going to use 5 1/2" (139.7mm) on my project.) Let's see if other experts here agree on that.

btw: that truck looks nice in front of your house, keith :D

It was pretty exciting to have my first material delivery! There will be much more, I'm sure! I expect there may be pictures of a dump truck (to haul away lots of concrete) and a concrete mixing truck in the hopefully not too distant future! 8) --Keith :mrgreen:

sharward wrote:

I would like to clarify something. In English we refer to "framing" as the lumber used to build walls, floors, ceilings, etc. -- If auf Deutsch there are different words to describe these different things, then no wonder you're confused! :shock:

thanks for claryfying that, keith.....but i think its the same in german ("rahmen")...

So, yes, you will use lumber to frame a wall structure ("framing the wall") and put multiple layers of gypsum on it, and then probably frame acoustic treatments and attach them to the finished wall.

ok, i got that now......so because our biggest concern is soundproofing, we will focus rihght now on that concept

I think 75mm studs may be too small for 3 layers of gypsum. I think 135mm would be better. (I'm going to use 5 1/2" (139.7mm) on my project.) Let's see if other experts here agree on that.

woohaaa.....that is very big. so you are using these studs just on the corners or is every stud that size? what do the other experts out there say? btw. i just received "building a recording studio" from jeff cooper from usa, because i couldn`t get it here. reading this makes my brain go :idea:. very enlightning that book :idea: :idea: it answered some of the smaller questions i had. but i still have some more. but i will make a sketch before i post them greetings to all of you btw did i say that i got 2 weeks off now :twisted:

themHorses wrote:

I think 75mm studs may be too small for 3 layers of gypsum. I think 135mm would be better. (I'm going to use 5 1/2" (139.7mm) on my project.) Let's see if other experts here agree on that.

woohaaa.....that is very big. so you are using these studs just on the corners or is every stud that size?

Every stud. Here in the US, most framing is done with "two by fours" which are 1 1/2" x 3 1/2". The next size up from that are "two by sixes" which are 1 1/2" x 5 1/2". I did a little Googling and I discovered that 135mm deep studs are a standard size and is close to the 5 1/2" studs I'll be using. However, others may have a different opinion on this. I've been wrong before -- so much so that I'm getting really good at it! :P Perhaps the lumber in your part of the world is stronger than ours, or much more expensive, or for some reason 135mm studs would not make sense. :roll:

btw did i say that i got 2 weeks off now :twisted:

Excellent! You'll have your studio all finished in that time, right? :lol: --Keith :mrgreen:

Three layers of plasterboard can be supported by a 2x4 WALL frame, but usually NOT for ceiling (unless it's a VERY small room) - however, these would need to be placed on closer centers - 400mm centers instead of 600mm centers - this will actually HURT isolation of the wall by a couple of dB. Better to use 2x6 wall framing (all of it is same size) and space the studs on 24" (600mm) spacing - this lets the wall "flop" just a bit more, which improves isolation a little. BTW, our lumber sizes aren't "real" - years ago, a 2x4 was really 2" x 4", and came from the saw mill rough surfaced, right out of the saw. Then they started smoothing the wood (planing it) which made the actual dimensions smaller - this eventually evolved to further reduction in size (but not cost :? ) to the present day, where a "2x4" is really 1.5" x 3.5", a "2x6" is really 1.5" x 5.5", etc - this is probably a major source of confusion when people in Europe try to match inches to millimeters. In either case, if you intend to support a ceiling frame on your inner walls you need to double the top plates - see the diagram below for a visual... Steve