Any suggestions to maximize isolation?

sammy87 · Post by **sammy87** » Sun Sep 18, 2005 5:55 am

We are about to start building our live room and I am concerned with the potential for sound transmission to our upstairs neighbors, a residential apartment. I've attached a jpeg with a rough outline for our construction plan, there are no measurements yet and the drawing is not to scale. The control room portion of the drawing has already been built; the windows have not been installed. Am I going to need to install 4 windows with this construction method? Will this provide sufficient isolation for our neighbors?

Thanks,
Sam

knightfly · Post by **knightfly** » Sun Sep 18, 2005 9:23 am

Sammy, welcome; please do NOT build anything further til you go here

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231

and follow ALL the bolded points - you are apparently already into "multi-leaf" territory, and you do NOT want to go there; more money, less isolation, less headroom for more disappointment.

It will take several hours of reading thru at least the first 3 links on that page, but will probably save you 10 TIMES that in "Aw Crap" comments alone... Steve

sammy87 · Post by **sammy87** » Sun Sep 18, 2005 12:23 pm

Thanks for the reply Steve, I apologize for the lack of background details in my previous post. I read through the links, found some good info and am ready to try again.

My business partner and I are building a recording studio in Chicago. Our building is a storefront on a busy street with lots of honking horns, trucks clanking and loud music from passing cars. We have the whole first level and above us is a three-bedroom apartment. Below us is the basement. The facility will include a front office, behind that will be the live room, then the control room, and finally, there will be a lounge in the rear of the building off the alley.

The original structure is brick from the street to where the live room ends and the control room starts. There is a 3’ wide gangway on either side of the building. The lounge and the control room are in an aluminum siding addition that was added to the main building at some point. The addition is only one story, so it acts like a deck for the upstairs apartment. It is also about 2 feet above the level of the existing structure. There is a significant step up from the live room to the control room. The exising floors and ceilings are not airtight. Just plywood or hard wood slats over ceiling joists, as far as I can tell.

We plan to use the control room mostly for post-production, mixing, mastering, and electronic music production. We will probably only be tracking in the live room a couple days a month. The rest of the time we hope to rent the live room as a rehearsal space for rock bands. Potentially very loud.

Since it is likely I will often be using the control room for my own projects while there is a band rehearsing in the live room, and since there are people living directly above, my top priority is eliminating noise transmission from the live room. The upstairs neighbors are friends of the studio, but they won’t remain so for long if they are kept awake at night by bands rehearsing below. I am much less concerned with noise coming in from the street, or noise escaping from the control room.

We are well into the construction process. The control room is almost completely done; there are no windows installed and we still need to finish the trim around the doors. My business partner is a carpenter by trade; he is doing most of the actual work, so forgive me if I don’t have 100% accurate measurements.

The floor is floated on rubber pucks and cantilevered 3-4’ over the ledge (remember the live room is 2 feet lower than the control room). On top of the studs we’ve laid one layer of plywood, one layer of drywall and one layer of mdf. All are 1/2'” I believe.

There is an outer wall, wood 2x4s, 16” on center, built on top of the floating floor with 2 layers of ½” drywall on the inside surface. This outer wall supports a ceiling, wood 2x4s, 16” on center, also with 2 layers of ½” drywall. Then there is a 1-2” air gap and an inner wall supporting an inner ceiling with the exact same construction techniques as the outer wall. I know there are 2 big problems with this design. First, the leaf on the outer wall should be on the opposite side of the studs, the outer side, not the inner side. Second, we should have used different width drywall on the inner wall so as to not match the width on the outer wall. Any other issues with this technique I should be aware of?

The live room has not been built yet, but my partner will probably build the live room the same way as he did the control room, unless I tell him other wise. My question for this forum is: what should we do differently in the live room to maximize isolation? Would it be better to build the outer shell on the existing floor and then float the inner shell on rubber pucks inside of that? We are looking at a budget at or around $5000.

My other question is about window installation. Since I have two shells in the control room, should I install two windows? They share the same floor, couldn’t they share the same window? Remember, I am not that concerned with noise transmission in the control room. The live room is where I want to focus my energy.

I can post more pictures if you need me to clarify something.

Thanks,
Sam

Post by **sharward** » Sun Sep 18, 2005 1:04 pm

Wow!

I thought I had heavy duty isolation requirements, but you, sir, take the prize!

What are the noise ordinances that apply to your part of town and to your type of construction (mixed use retail & residential)? It would seem to me that would be your absolute minimum target noise levels, and you'd preferably want to exceed that significantly so that you have some wiggle room.

Got drawings? Photographs?

--Keith

sammy87 · Post by **sammy87** » Mon Sep 19, 2005 11:37 am

I'm not sure what the noise ordinances are in Chicago. But like I said, it is a really busy street day and night, people don't expect absolute silence. In fact, in the part of town where we are building, there are a number of live music venues at street level with absolutely no soundproofing. Obviously there is a ton of leakage out onto the street at these places. I'm really not worried about transmission loss at street level. What concerns me most is isolating the space for the sake of the upstairs neighbors. I looked at your thread, Keith, and got some good ideas. I think we have similar requirements.

Here is a quick drawing of the plan for the live room. The black lines represent existing walls. Redish boxes are bricks, the blue lines are where I would like the live room to sit in the space. However we are very flexible about this

sammy87 · Post by **sammy87** » Mon Sep 19, 2005 12:30 pm

I was at the studio today and I got some more details about the construction of the existing space.

The east and west walls are brick with 1"x2" firring strips on the inside, on top of which is plaster and lath.

Part of the north wall shares this type of construction because this wall is the end of the original structure. The control room is already built just beyond the north wall, using 2x4s 16" OC and 2 layers of drywall, the whole thing is raised about 2 feet above the level of the rest of the building. A portion of the control room is cantileverd out into the space where we will build the live room. I know this is convoluted and is probably hard to visualize. I will post pictures tonight or tomorrow.

The south wall is just floor to ceiling metal studs with one layer of drywall on the opposite side.

We've got a 12' high ceiling. The flooring above is nailed to 13"x3" wood joists, 16" OC, running east/west. On these joists are plaster and lath, like the walls. There are a number of penetrations through the plaster and into the apartment above, like conduit, plumbing and gas.

Our floor boards are nailed to 6"x4" beams, 16" OC, above a 5 1/2 foot concrete basement.

Any suggestions on how to approach this room are welcome. It seems the more I read about other people's project, the more lost I get. I've got some ideas, but no solid plan of attack is forming. The walls and the ceiling have a ton of plaster on them. If there is anyway to avoid removing it all, I'd be thrilled. I'm willing to sacrifice as much space as I need to. We've got plenty of height to work with.

Another factor to consider is time. We need to get this room operational by January 1.

Thanks in advance for any assistance.
Sam

Post by **sharward** » Mon Sep 19, 2005 5:51 pm

sammy87 wrote:I'm not sure what the noise ordinances are in Chicago.

Here are the noise regulations in Chicago.

It appears that there decibel limits for specific frequencies, and those limits vary depending on the district.

This item jumped out at me:

11-4-1380 Public nuisance declared--Abatement.
Any emission of noise or earthshaking vibration from any source in excess of the limitations established in or pursuant to this article shall be deemed and is hereby declared to be a public nuisance and may be subject to summary abatement procedures. Such abatement may be in addition to the administrative proceedings, fines and penalties herein provided. The commissioner is empowered to secure the institution of legal proceedings through the corporation counsel for the abatement or prosecution of emissions of noise and earthshaking vibration which cause injury, detriment, nuisance or annoyance to the public or endanger the health, comfort, safety or welfare of the public, or cause to have a natural tendency to cause injury or damage to public or property. Such legal proceedings may be in addition to the administrative proceedings, fine and penalties herein provided.

Print out the whole thing and study it carefully, get confused, read it again, get more confused, and hopefully after a few more rounds, it will start to make some sense. If not, call your city's Environmental Complaint Line and see if you can speak with someone who can answer your questions.

But like I said, it is a really busy street day and night, people don't expect absolute silence. In fact, in the part of town where we are building, there are a number of live music venues at street level with absolutely no soundproofing. Obviously there is a ton of leakage out onto the street at these places.

From what I gathered from my cursory review of the regulations, they may be in violation of the law; if so, they're getting away with it for now, but that could change if there's a crackdown at some point in the future.

I'm really not worried about transmission loss at street level.

Maybe you should be.

I would hate to see you build so nicely, only to be shut down in the future.

What concerns me most is isolating the space for the sake of the upstairs neighbors.

Yes, that is quite understandably the greater concern.

--Keith

sammy87 · Post by **sammy87** » Tue Sep 20, 2005 7:17 am

Thanks for the heads up, Keith. I'll check those resources and make sure we are in compliance.

I'm reading through other people's threads, and learning more as I do, but I still have a ton of questions. We want to start building as soon as possible, but I'd love some guidance from members on this forum before we just jump in and end up making dumb mistakes.

I understand that the most efficient method of isolation is mass / air / mass. I should probably use our existing walls and ceilings as the outer leaf in a two leaf system. However, the existing structure is not up to snuff as far as being airtight, certainly not the existing ceiling nor the non-brick walls to the north and south of the live room. It would take a TON of time and effort to get them workable, more than we can afford. In cases like this, is it okay to "start from scratch?" By that I mean, Can I build a new outer leaf withing the existing structure, making sure that it has plenty of mass and is airtight, and then float the inner leaf inside the new outer leaf? I could provide the same size air gap between these two new leaves as I would if I were using the existing structure as the outer leaf.

Unless I hear differently, I imagine we will end up suspending a new ceiling from the existing one, and building new walls to meet this new ceiling. We would cover all surfaces with 2 layers of 5/8" drywall and caulk all of the seams. Within this shell, we would float a floor of plywood and mdf on rubber pucks and build walls on top filled with fiberglass insulation. The inner walls would support the inner ceiling, also filled with fiberglass insulation. We'd cover all surfaces with 3 layers of 1/2" drywall and caulk all the seams. Will this work? How much transmission loss can we expect if it is carried out properly? What details am I missing, or what variables am I overlooking?

Sam

Post by **sharward** » Tue Sep 20, 2005 2:14 pm

sammy87 wrote:I'm reading through other people's threads, and learning more as I do, but I still have a ton of questions. We want to start building as soon as possible, but I'd love some guidance from members on this forum before we just jump in and end up making dumb mistakes.

We won't be shy!

Just develop your plans and "think out loud" here. We'll do our best to keep you out of trouble.

I understand that the most efficient method of isolation is mass / air / mass. I should probably use our existing walls and ceilings as the outer leaf in a two leaf system. However, the existing structure is not up to snuff as far as being airtight, certainly not the existing ceiling nor the non-brick walls to the north and south of the live room. It would take a TON of time and effort to get them workable, more than we can afford. In cases like this, is it okay to "start from scratch?" By that I mean, Can I build a new outer leaf withing the existing structure, making sure that it has plenty of mass and is airtight, and then float the inner leaf inside the new outer leaf? I could provide the same size air gap between these two new leaves as I would if I were using the existing structure as the outer leaf.

I think I understand your question. You're wondering if you can kind of "ignore" the existing structure so you can focus on building two new leaves. Sometimes that's necessary. However, you mustn't underestimate the detrimental effect of extra leaves. If you gave me a bunch of building materials, I could build you a two leaf system and you'd have a certain level of soundproofing. Then if I took it all apart and reassembled it differently, using the exact same amount of mass and ending up with the exact same square footage, only I spread the mass around so that we had three or even four leaves, the room would suck.

There are was to mitigate the effects of third and/or fourth leaves. I have a third leaf in my project -- it's my roof. However, my attic is vented and the first two leaves (ceilings) will be plenty beefy with a decent sized gap between them (about 12"), so this is a calculated risk.

You may have no choice but to deal with the imperfections in your existing structure. However, without any photos or detailed illustrations showing these items, it's hard to get specific.

Unless I hear differently, I imagine we will end up suspending a new ceiling from the existing one, and building new walls to meet this new ceiling. We would cover all surfaces with 2 layers of 5/8" drywall and caulk all of the seams. Within this shell, we would float a floor of plywood and mdf on rubber pucks and build walls on top filled with fiberglass insulation. The inner walls would support the inner ceiling, also filled with fiberglass insulation. We'd cover all surfaces with 3 layers of 1/2" drywall and caulk all the seams. Will this work? How much transmission loss can we expect if it is carried out properly? What details am I missing, or what variables am I overlooking?

You're basically on the right track. I don't have the fancy calculators to predict the performance of that system (and, mind you, there are still incomplete parts of the equation, such as the size of your air gap between the leaves (measured from the backs of the drywall -- the studs don't count, as long as each leaf is completely decoupled) and the situation with your existing structure.

You'd probably be better off beefing up your existing leaf rather than hanging a new ceiling on the bottom of the joists. It's more time consuming but the effort will pay off in spades. I spent several hours doing this to my east wall today. Just make sure you don't overload that ceiling, or people will die!!!

You'll probably need to up the ante to three layers of drywall and maybe four. You'll also probably want to use 5/8" instead of 1/2" -- more mass, same effort. You may also want to use Green Glue somewhere -- I'll leave the specifics of that advice to Steve or others who may have more knowledge of it. (I only became versed in Green Glue in the last 24 hours -- I'm the wrong person to ask about it yet.)

Regarding the floating floor -- you may end up with a floor that, in spite of your best efforts, is actually worse than the floor you currently have. What kind of floor are you on now? Concrete slab? You're on the ground floor, right? I debated floating a floor for ages. I ultimately decided to replace my lousy garage floor with a structural grade isolated slab. Mmm, that will be fun (not).

Time for us to see photos and detailed drawings of your space. Don't forget to include utility locations (water valves, electric service panels, drain pipes, water heater -- stuff that probably can't be moved and/or must be accessible and servicable).

Take a deep breath and muster up as much patience as you can. Borrow some if you need to. You're in for quite a rollercoaster ride -- but you're not alone and there are some very helpful folks here to get you unstuck when you need it.

Please tell me you're getting permits for all this... You're in commercial space, right? That makes it all the more important -- try to fly under that radar and you're sure to get nailed, especially in a big city like yours.

--Keith

mikeklooster · Post by **mikeklooster** » Tue Sep 20, 2005 2:53 pm

Keith your spoiled because you dont complicate your life like I do. Im not sure I have the details, but if your going to use the roof as leaf 1 then you are now venturing in to the unvented attic realm. Its not fun. check it...http://www.johnlsayers.com/phpBB2/viewt ... highlight=
it somewhere closer to the end..

Post by **sharward** » Tue Sep 20, 2005 3:07 pm

Mike, did you mean to reply to this thread? Because our Chicago friend here has a residential neighbor above his commercial space -- not an attic.

For the record, I will have two very beefy ceilings on my project about a foot apart. I don't need to worry about the unvented attic stuff.

--Keith

mikeklooster · Post by **mikeklooster** » Tue Sep 20, 2005 4:47 pm

sorry, lazy, but i do remember reading about that a little while ago. And thats what I meant when i said you dont have to worry about it because you dont complicate your life is refering to the fact Im set on having a high as possible ceiling which has forced me to even be able to say UNVENTED attic. My apologies, Ive been away a minute, and Im a little rusty and trigger happy. Its just when you mentioned the whole outer leaf is structural thing it flashed me back to when you figured out that if my roof was vented, its not a leaf. Strike that one from the record..

mikeklooster · Post by **mikeklooster** » Tue Sep 20, 2005 4:47 pm

I was posting under the influence

shmackdaddy · Post by **shmackdaddy** » Tue Sep 20, 2005 6:58 pm

sorry, lazy, but i do remember reading about that a little while ago. And thats what I meant when i said you dont have to worry about it because you dont complicate your life is refering to the fact Im set on having a high as possible ceiling which has forced me to even be able to say UNVENTED attic. My apologies, Ive been away a minute, and Im a little rusty and trigger happy. Its just when you mentioned the whole outer leaf is structural thing it flashed me back to when you figured out that if my roof was vented, its not a leaf. Strike that one from the record..

I was posting under the influence

Post by **sharward** » Wed Sep 21, 2005 1:01 am

Friends don't let friends hijack peoples' threads with incoherent ramblings.

Don't you have a designated typist?

--Keith

For those who don't get the pun -- there was a big anti drunk driving campaign years ago here in the U.S. The motto was "Friends don't let friends drive drunk."