Hi! Let me first start off by introducing myself to y’all, as this is my first post on this board. My name is Geoff, I live currently in LA, and I am, pretty much, a composer, drummer & engineer.
I’d also like to start by thanking those of you who’ve been putting forth information so freely on this and other sites, and in your book(s). I’ve been researching in preparation for this project for a while, mostly on this site, as well as the TOMB (from where I was referred to this site), and don’t think I could’ve come even as far as coming up with (hopefully) decent questions to ask without all the info that everybody, but especially John, Knightfly and Rod, as well as Ethan and JWL, have made available.
OK, so I’m in the PLANNING STAGES of building a Music Production Workspace (note, I’m not calling it a studio) inside of a 1950’s travel trailer (also known, I think, as a “caravan” to some). This trailer will remain parked, for the most part, all the time, unless I move into another home, in which case it’ll be moved there. I know there’s a lot of people out there who would say a trailer studio is a bad idea to start off with. Let’s just assume that I’ve researched and weighed out the pro’s and con’s, and decided that this is really the best thing for me in my situation right now.
So, the approx. dimensions of the trailer is 25’ long, 8’ wide, and with a sloping roof starting from 6’ in the back to 7’ in the front. My current plan is to take the front, say, 10’ of it and build a completely separate room-within-a-room, if possible, so that I can minimize my impact of playing drums occasionally on the neighbors about 50’ feet away. I’ve been doing a lot of digging on this forum, as well as others, and I’ve bought and read (mostly) through Rod Gervais’ book (thank you, again, Rod).
This space will be used for (usually) just myself, as what I do is write and record soundtrack music/scores for TV/film/etc. A lot of what I do involves midi and software instruments or things I can plug in directly, as well as acoustic guitars and such, but I do, from time to time, like to play some drums, being that that’s what I’m best at, as well as other acoustic instruments, and it seems a waste to not utilize all my abilities. I don’t play particularly loud, and I’m not expecting total or near-total isolation from the outside world in this case, but the more isolation I can accomplish, the easier my work-flow will be.
I’ll say this: if worse came to worse, and I couldn’t do ANYTHING AT ALL to increase TL, I still feel I could use the trailer for my workspace. It’s just that if there’s any way to improve it, I’ll spend some money on it, seeing as this is, mostly, my career and livelihood.
Speaking of money, I’m trying to keep my total budget for the iso-room below $4000, if possible. If spending another grand or 2 will make the difference between “ok” and “really good”, then I’d spend it, but I’ve got a baby to feed and clothe, so… you know…
I want to start with figuring out the floors, because I feel that that’s where the weakest link in a room-within-a-trailer will be. [I know that there’s inherent problems with having soundwaves resonating through the aluminum shell, and I’ve got some ideas for dealing with that based on what I’ve researched, but I don’t feel like I can make a concrete plan (get it, concrete?!?! :D ) for those things until I figure out how much isolation I can get out of my floor, seeing as that’s theoretically the only place where the inside room will touch the trailer.]
The floor of the trailer is built on top of a steel frame with, what looks like, one layer of plywood on top, followed by linoleum tiles, which span the entire interior of the trailer. Sandwiched underneath the plywood and between the steel beams is, what looks like, regular fiberglass insulation. Keeping that insulation from falling onto the street is, (again) what looks like, some sort of rolled roofing material sheets. The trailer has 1 single axle with a wheel on each side. There are also currently 4 scissor jacks bolted to the underside of the frame that support & level out the corners. Lastly, there is a tongue jack that holds up the part that would normally hook onto whatever vehicle is towing the trailer. So, that’s 2 wheels and 5 jacks keeping the trailer off the ground, total. (I don’t know if that’s relevant, but I’m just trying to give as much info as possible)
So, I don’t have a concrete slab to build on top of, and pouring enough concrete to make 2 floating layers of concrete wouldn’t seem to be an option. I know (according to everything I’ve read, at least) that it’s unlikely that a floated wooden deck on a joist frame would help me much, if not, in fact, hurt me… so…. Now what??
My first guess is that all I can really do is add MASS to the floor, to bring down it’s resonant frequency as best I can.
My second guess, or more a question, is: can I use Constrained Layer Damping (as described on p.79 of Rod’s book, for those of you following along at home) to help out with the floor? Like say, for example, I put 3 layers of plywood down with greenglue between each. What would that do to the impact noise from the drums? What about the airborne noise?
I had a conversation with somebody from the Super Soundproofing Co. (who I contacted because they aren’t that far from where I live. They are the same as soundproofing.org) a couple of months ago. Besides a bunch of other suggestions, the salesman suggested using 2” closed cell vinyl-nitrate foam on top of the existing floor, with two layers of plywood directly on top of that. Here’s a link to the closed cell foam:
http://www.soundproofing.org/sales/prices.html
would this act as a dampening layer? I can’t imagine it would function as “air” or a “spring” between two layers, right?
Now, I know this store has come under some scrutiny from people for giving out information/advice that is questionable, or maybe just not applicable in studio situations, AND I also realize that this IS a business, and that they’re going to try and sell me a product that they have in their warehouse, despite all the disclaimers on their site proclaiming otherwise. That being said, is there any validity to the 2” closed cell foam idea?
My next question is, when dealing with Constrained Damping Layers, is it as important to add Mass to BOTH sides as it is in a M-A-M setup? Say the Closed Cell Foam thing WAS a good idea, would it help to pour Gypcrete on the existing floor first, in order to add some mass to THAT layer? Or would it be just the same to add mass to the top layer, in the form of, say, Durock sandwiched between two layers of plywood, with Green Glue between each?
I know this is becoming a jumbled mess of ideas and questions, and I apologize for that. The more I research, the more jumbled my brain gets, and the more sleepless nights I have, thinking about this stuff.
I’ve made up a quick diagram of pretty much all the ideas I have for the floor, including Mass and Dampening. I haven’t figured out how to get SketchUp working right for me yet, so I hope you can excuse my photoshop drawing.
What It basically shows is:
THE EXISTING FLOOR: Steel beams, plywood on top of them, linoleum tiles on top of that, with fiberglass insulation and rolled roofing material underneath.
WHAT I’D (MAYBE) PUT ON TOP: Poured Gypcrete, followed by 2” closed cell vinyl-nitrate foam, topped off by a mass-sandwich of durock between 2 layers of plywood, with GreenGlue between each.
I would, ideally, then build new walls off of this floor and frame a ceiling that rests on top of those walls. Again, though, I’d like to get the floor figured out first, so I can match the TL of the walls/ceiling to that.
So, to recap the questions:
1) Is Constrained Layer Damping useful for isolation on a floor where floating is not an option?
2) Is 2” Closed Cell Vinyl-Nitrate Foam useful as a Damping Layer? And how would it compare to GreenGlue?
3) when dealing with Constrained Layer Damping, is it as important to have Mass on BOTH sides of the damping layer? Or would the same amount of Mass, spread out less evenly, produce the same results (because a CLD system still only gives you ONE LEAF)? As an example, would you get the same results from GreenGlueing one 5/8” and one 3/8" layer of sheetrock together as you would from GreenGlueing together one 1/4” and one 3/4” layer of sheetrock. (This is more a theoretical question, obviously).
4) Looking at the diagram, is there any value to what I’m proposing? What materials would you keep (if any)? What materials would you not bother with (if not all of them)?
5) Would a floor like this (or whatever floor you recommend) be stable enough to support independent walls and a ceiling?
So, that’s it for now. I hope I’ve given enough (or more specifically, the correct) info to answer with. Let me know if you require anything else.
Thanks in advance,
Geoff
I'm not going to float a floor, so....
Originally posted at johnlsayers.com, topic 10977.
Wouldn't the fact that this frame is on wheels be enough decoupling already?
Decoupling from the driveway, yes, but any sound that gets out of the trailer (by whatever means) will become airborne into the outdoor space/air. That's more what I'm concerned about. Now, say I had the trailer parked inside a big-enough garage. That would probably be enough, or at least a lot closer (Instead of room-inside-a-trailer it would be trailer-inside-a-room :P ). Unfortunately, I have no indoor space to park the trailer in. so....Wouldn't the fact that this frame is on wheels be enough decoupling already?
I don't follow.
The point of a floating floor is to get it "off" of something...yours is effectively "on" nothing :)
Like that old man said, "seems like too much sugar for a dime boss."
Hmmmm....
I don't think I'm getting where, exactly, we're not understanding each other.
As far as I can tell, the sound of the drums would be getting out of the trailer from all directions: the walls, the ceiling, and the floor. The floor on this thing is NOT very massive on it's own, so I don't see how it would stop sound, especially low frequencies, by itself. As it is, airborne AND impact sound will appear on the other side of the floor as SOUND, right?which, then, will travel through the air to the neighbor's house. See diagram below... (soundwaves coming through the floor are represented in BLUE)
If the drums were somehow actually magically floating in midair, with nothing surrounding them, you'd still hear them 50' away when played. Now, if you you surrounded those drums (and the drummer, of course) in a completely enclosed box made out of 1 layer of plywood, and this box was also somehow actually magically floating in midair, you'd be able to hear the drums from the outside of the box, right?
I'm not trying to be argumentative, really... I'd love to find out that everything would be fine without treating the floor. Like I said in my original post, I'm NOT trying to float a new floor, I'm just trying to add MASS and DAMPING to lower the resonant frequency of the existing floor leaf.
The is the easiest. Build a lip around the periphery of the trailer to act as a second leaf. If the trailer will not be moved for while use concrete blocks.
Andre
Considering the stress people seem to put on AIRTIGHT construction between leaves of MASS, wouldn't I have to seal up that concrete block structure pretty good? which, in turn, would be pretty difficult around the wheels and the tongue, I think, without making it a somewhat more permanent structure, and making me have to deal with alot more in terms of building codes and such. Even then, it would still only be a "Thin Leaf-Air-Mass" structure. And I'd STILL have pretty bad (I think) flanking paths between the original floor, if it's untreated, and the outside wall of the trailer. I'm not necessarily looking for easiest. I'm willing to put in the time and work to do it best, within my budget, which isn't huge, but isn't nothing either. The concrete block idea seems like something I might try AFTER I deal with the trailer's floor, and the walls and ceiling, and if I THEN find that I still need more isolation. Here's the questions, one more time, just so the topic doesn't get confused: 1) Is Constrained Layer Damping useful for isolation on a floor where floating is not an option? 2) Is 2” Closed Cell Vinyl-Nitrate Foam useful as a Damping Layer? And how would it compare to GreenGlue? 3) when dealing with Constrained Layer Damping, is it as important to have Mass on BOTH sides of the damping layer? Or would the same amount of Mass, spread out less evenly, produce the same results (because a CLD system still only gives you ONE LEAF)? As an example, would you get the same results from GreenGlueing one 5/8” and one 3/8" layer of sheetrock together as you would from GreenGlueing together one 1/4” and one 3/4” layer of sheetrock. (This is more a theoretical question, obviously). 4) Looking at the diagram, is there any value to what I’m proposing? What materials would you keep (if any)? What materials would you not bother with (if not all of them)? 5) Would a floor like this (or whatever floor you recommend) be stable enough to support independent walls and a ceiling?The is the easiest. Build a lip around the periphery of the trailer to act as a second leaf. If the trailer will not be moved for while use concrete blocks. Andre
xSpace and AVare,
I hope I didn't come across as being unappreciative of your suggestions. That was NOT my intention at all. I have been reading up on this site for a couple months now and generally find both your observations helpful and seemingly well-informed.
I'm trying to avoid doing any construction outside of the trailer, as I don't own the driveway it'll be parked in (we rent in a small apartment building). Even though the building is owned, and mostly occupied by extended family members who are very supportive of this project, I wouldn't want to start making them nervous by building on top of their driveway, especially when we're not sure how long we'll be here.
I just saw a thread (that I somehow missed before) about someone using 1" or 2" 705 to essentially decouple a double plywood leaf from an attic floor (as suggested by Rod G.).
As an alternative to my first diagram, would 705 be able to be used instead of the 2" closed cell vinyl-nitrate foam as a layer between the original floor and the top layer?
How would that compare to the vinyl-nitrate?
Would using 705 require greater attention to calculating the amount of weight that would end up on top of it?
Thanks again,
Geoff
PS - I know there's plenty of other folks besides who I named in my first post who deserve thanks for this site's continued existence and prosperity, including the rest of the moderators, Sharward and AaronW. If I left your name out, it wasn't due to a judgement on your credit-worthiness. I guess this type of thing is why they always cut people's speeches short at the Oscars :blah: :? :D It seems easier, sometimes, just to say nothing at all, rather than stumble over trying to condense one's thankfulness.
Both? I had more then two!!! I'm kidding...really. Let me say my thinking on a trailer. Your weakest link will not be the floor, it will be the whole thing, walls, floors, ceilings, et. al. Flanking path? It is a flanking path!! It wasn't built, especially back in 1950ish, to do anything more then it does...sit on a frame, ride around and keep your head dry and the beer chilled. Next comes the metal frame. It too was designed to do minimum work load. Carry the walls and floor and ceiling down the road. Maybe get over a few bumps now and again. There isn't any mass to speak of on any part of this structure. You shouldn't count the exterior as anything viable towards isolation. If anything, the walls need mass as much or more then the floor, because the floor has some mass with the plywood or most likely cut up pieces of plywood that have replaced the particle board over the years. When you start loading that little metal frame up with poundage, pound after pound after pound, believe me, it will sag and it will sag immediately. Then it will >have< to be shored up with blocks, it is no longer road worthy and cannot be licensed or tagged and moving it could well be the last straw that causes it to break in half. In the end, whatever information you have gathered from Rods book or the websites you visit and trust, that is knowledge you can use right now. You can mass it up all over. Once you decide that you require more, maybe then would be a good time to look into other alternatives. But I must say, someone may have already had success with this idea and hopefully they can shed a light on your best options. As for CLD or the closed cell foam I dunno, whatever these guys say is what I would consider doing. Brien... generally find both your observations helpful and seemingly well-informed.
a +1 for what Brien wrote.
For the record, I meant both of you guys :)
Anyway, I understand that there's a bunch of issues with the walls and ceiling that will need to be taken care of. I've thought about some ideas for adding mass to the existing ones, including first sealing up the inside of the frame with caulk where there's seams, then doing what Rod suggests for in between ceiling rafters (p.67 in the book) with tightly fitting a couple of layers of sheetrock between the studs of the orginal walls and ceiling (greenglue between), and sealing all that up real well, as per the usual instructions.
I know, also, that all this stuff will and a bunch of weight. I'm considering the fact that I've taken out a bunch of weight in the form of appliances (stove/sinks/toilet) as well solid birch cabinets, shelves and walls, a couch and a table, etc.
My actual equipment setup is quite small (and I'd take all that out if I needed to move it from one location to another), so I'm feeling that, as long as I don't put in much more weight, in the form of sheetrock and studs, than I took out, the trailer should be able to handle it. I've had scissor jacks put in near the 4 corners so some of the burden of weight is taken off the wheels and tongue jack as well. I can still put up some columns of concrete blocks to help out, but that's different then a sealed concrete structure around the perimeter.
Finally, I get that the whole thing is one big flanking path. But if I can enmassen (en-mass-en [v.- to add mass to], I do not think it is a real word, but maybe today should be it's birth :P ) the walls and ceiling, maybe it'll be worth doing something to reduce transmissions getting to the original floor & steel beams, therefore reducing the flanking path to the outside aluminum in the first place. Hence, my original post...
Of course, these things pertaining to the floor are all theories, since I wasn't able to find much in the way of other examples of people in the exact same situation. The Container Studio thread was very helpful, but they didn't seem to do much with their floor, besides fill in the cracks with stiff fiberglass and put 2 layers of hardboard down, and it didn't seem like isolation was their #1 concern.
If two layers of plywood with green glue is the best that I can hope for (and all you fine people think it's good enough) for the floor, then so be it, but, if I can improve upon that somehow, to the point where it'll be worth building new walls and a ceiling on top of that, then I'd like to find out how.
Sorry for my perpetual rambling and run-on sentences.
Thanks again,
Geoff
"so we stuffed it with insulation, added a layer of >rubber<, and laid two sheets of particle board flooring sheets that have a tongue and groove join." /quote from Container build. I think isolation was high on the priority list. Looks like mass/air/mass with a rubber decoupling layer.The Container Studio thread was very helpful, but they didn't seem to do much with their floor, besides fill in the cracks with stiff fiberglass and put 2 layers of hardboard down, and it didn't seem like isolation was their #1 concern.
What was the air, in that situation? was it the insulation? I don't have grooves in my floor, but would rubber be a good floor decoupler in my case? and would the vinyl-nitrate maybe have the same properties? Are there other technical names for "rubber", so I'd know what to look for? Maybe rubber's just rubber, I don't know... The only reason I said isolation (and I meant the floor) wasn't as big a concern was because the picture shows the container just sitting on the ground, which I feel puts them back in the same old situation as they'd have been in building on top of a basement floor, no?"so we stuffed it with insulation, added a layer of >rubber<, and laid two sheets of particle board flooring sheets that have a tongue and groove join." /quote from Container build. I think isolation was high on the priority list. Looks like mass/air/mass with a rubber decoupling layer.
In a typical new construction insulation is always part of the air.
As far as the basement floor thought. sort of. A basement floor is often concrete so can be built onto. This is a container with a lift in the floor that creates a cavity that they wanted to get rid of, so insulation was used. It is still the same mass/air/mass principal except it is earth/insulation/dense material.
Had they not chosen to use insulation in this area, I dunno, a hollow or ringing may have been the result from not doing it like this.
DO NOT GUESS AT YOUR WEIGHTS. CALCULATE THEM.
This report gives you some idea of what is done in a professional mobile facility and what sound isolation was achieved. BBC RD 1984/3
Andre
Thanks for the report. That's a nice piece of info right there! :)
and don't worry, I will weigh everything I take out so I know what my weight restrictions will be when building back up. There are some things that were removed before I got the trailer (like the stove and the toilet) so I'll have to make some educated guesses there, but I'll err on side of caution.
xSpace, I see what you mean about the container and the hollow cavity and such.
Thanks again, both of you. :P
Still, if anybody out there's got any ideas about the closed-cell vinyl-nitrate, and how it compares to rubber. That'd be great too...
*b-b-b-b-bumb* :poke:
Hopefully I won't piss anybody off by asking this. But... :horse:
Does anybody have any thoughts about the questions I originally posed in the first post?
I appreciate all of xSpace and Andre's advice, but it still leaves me with the question of the best, most efficient way of beefing up/dampening the existing floor of this tralier.
At the very least, could someone maybe tell me what kind of rubber is used in a situation like they had with the container studio's floor:
http://www.johnlsayers.com/Studio/Pages/Container.htm
?
There seems to be alot of things called "rubber" out there, that come in sheets, and I was curious if one material is better than another.
Would a closed-cell or open-celled foam possibly fall into this category? (Including the vinyl nitrate I mentioned in the first post)
Also, when you're dealing with damping on a floor, as opposed to a *spring*, are you still looking for that compression point between where the material gives just a little to the weight thats on it, and where it's totally compressed? Or are the concepts different?
Any more/other assistance would be greatly appreciated. :D
Thanks,
Geoff
Achieving decent isolation at low frequencies requires mass. This is the truth.
You can do what you want, but you will not get effective isolation at low frequencies with out mass. If you try and buy rubber etc without doing the calculations, you almost be worse off than not putting the rubber in.
Andre
I'm not sure which calculations you think I'm not planning on doing. I'm asking, I believe, questions which will, in fact, help me to do the calculations. I'm following a suggestion (by xSpace) that the Container Studio's floor was intended to be helpful in sound isolation. So, I'm asking a specific question:Achieving decent isolation at low frequencies requires mass. This is the truth. You can do what you want, but you will not get effective isolation at low frequencies with out mass. If you try and buy rubber etc without doing the calculations, you almost be worse off than not putting the rubber in. Andre
I followed that up with a specific question about damping and compression:could someone maybe tell me what kind of rubber is used in a situation like they had with the container studio's floor:
I don't think either of these questions suggests that I'm "just gonna do whatever" (that's not a quote from you, it's just the feeling I'm getting from your response)... They are specific questions designed to help me figure out WHAT calculations I need to make. That goes, really, for the questions I posed originally as well. I understand that you need mass to achieve decent isolation, but, according to Rod's book (p.80), using Damping systems, like Green Glue, can make it so the (dampened) isolation achieved by 2 layers (with damping in between) can (potentially) be greater than the sum of it's parts. Therefore, I'm trying to go about this in the most efficient and effective way I can, which is why I posted my original question in the first place. It was all about using Constrained Damping Layers in a floor situation, if that would help, and what materials would be best used for damping AND for mass in that situation. Are you telling me there's nothing I can do to even improve the isolation of the trailer's floor, except some layers of plywood with GG? If that's your opinion, then I can accept that, though I'd personally want to have a 2nd or 3rd (or 4th) opinion. Are you trying to nudge me towards a certain calculation, that is perhaps in a sticky or thread somewhere, which I am being blatantly ignorant of? If you don't know the answers to the questions I've been asking, I can accept and respect that as well. This isn't a standard, everyday studio build I'm trying to do here, and what my options are are a bit different than what they would be in a building. If there was more information about this type of thing available, I wouldn't be here asking all these questions (or at least as many) in the first place. I'm hoping that some of the other *big guns* on this site could weigh in with their thoughts, as well. Thanks, Geoffwhen you're dealing with damping on a floor, as opposed to a *spring*, are you still looking for that compression point between where the material gives just a little to the weight thats on it, and where it's totally compressed? Or are the concepts different?
No insult, but it is difficult with out progress in the thread. I'm going to try and start from the beginning, as opposed to just giving comments.
Yes.Is Constrained Layer Damping useful for isolation on a floor where floating is not an option?
No.Is 2” Closed Cell Vinyl-Nitrate Foam useful as a Damping Layer? And how would it compare to GreenGlue?
No, and no.(a)when dealing with Constrained Layer Damping, is it as important to have Mass on BOTH sides of the damping layer? (b)Or would the same amount of Mass, spread out less evenly, produce the same results (because a CLD system still only gives you ONE LEAF)?
Your restriction is weight. The system you designed is effective in a manner, but too heavy for a trailer.Looking at the diagram, is there any value to what I’m proposing? What materials would you keep (if any)? What materials would you not bother with (if not all of them)?
Why are you still planning on doing them? Your restriction is weight do weight calculations for what you have, and have removed. Then the weights of various proposed wall, and ceiling systems. this will define what isolation is needed from the floor. The weights will also be restricted by what will keep the trailer portable on roads and with out collapsing when moved. We can not give useful advice without knowledge of the room (ok, trailer in this case) as an entire system. AndreI'm not sure which calculations you think I'm not planning on doing. I'm asking, I believe, questions which will, in fact, help me to do the calculations.
OK. Thanks for answering some of my questions.
I'll come back with some numbers when I can and give it a go again...
Rock on, y'all :jammin:
-Geoff