Author Topic: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!  (Read 14663 times)

tacobar

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I own a NYC Coop and whilst my wall is not super thin, I can hear my very vocal neighbor, his screaming banshee gfriend and his TV that is right up against our common wall.  Since it's a Coop, I cannot actually tear down the wall, re-insulate and add dry wall.  However, I am considering adding another layer of dry wall with Green glue.  The thing is I have no idea what my current drywall is made of, I was told double sheet rock.  Can I hang another drywall on top of it provided I find the studs?

Another suggestion I receive from a Contractor is that he can build an 1" frame outside my wall, insert insulatiion and then dry wall.  That will create an empty space.  Beside loosing 1.5 inches off my already small apartment, will it really reduce the sound?  What type of insulation would work best? 

Thanks - it has been therapeutic reading these blogs.  Whilst my problem is no where as bad as some of yours, I do feel better, like I'm not alone.  Now, I try to have a laugh when I hear my stupid next door misfits, instead of anxiety and dread.  Coops are great in that when a resident misbehaves, he gets fined.  I hope he gets fined to the point where he packs up and leaves.  I do feel sorry for Condo dwellers who have no recourse.  Life is hard as it is, I really can't understand people who are so inconsiderate as to blast music or tv all hours and has such utter disrespect for other people.  Even tho' my neighbor bugs the cr*p out of me, when I watch tv late at night, I use my superb wireless Senheiser studio headphones.  They are awesome, lightweight, rechargable, and when I move, I don't have to lug 40 speakers with me. 

johnbergstromslc

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #1 on: March 08, 2008, 01:43:15 AM »
Another layer of drywall will help, certainly; you'll be increasing the mass by 50% +, depending on the thickness you use.  I recommend 5/8" at least, or 2 layers of 1/2" if you really want to be gung ho about it..   If you use a very thick layer of Green Glue between panels, that will help even more.  Just be sure to seal up all the electrical boxes, penetrations, etc.

A second wall, like the one your contractor recommends, would cut sound significantly.  But the lost space is a high price to pay for their noise.  You'd probably reduce the market value of your unit as well. 

Are you sure you can't do more aggressive remodeling, like fixing the existing wall?  Maybe if you appealed to your co-op board regarding how bad the noise is, they might listen.

tacobar

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #2 on: March 08, 2008, 07:01:53 PM »
Hi John, 

Thanks for your speedy reply. 

Since it's a Coop, I don't actually own the walls, so I cannot tear it down and rebuild.  And God forbid if I puncture the other side into my noisy neighbor, I will start WWIII.

I spoke to my building manager yesterday and he's very well aware of our sound issues.  He recommends adding another layer as well to create density.  However, he said that my wall is made of mesh wire, sheetrock, and then a coat of plaster.  He said it's not necessary to hang new dry wall onto the studs because if I use 3/4" nails (with 1/2 sheetrock) it will catch on the mess wire for support (not sure if studs are even wood since it's a 25 story building).  Do you know if that's correct?   I'm a little aprehensive about this suggestion.  I would feel much better if you could confirm. 

Also, some believe 2 tubes of green glue for 4x8 sheetrock is enough, some recommend 3.  Can you confirm.  I'd rather do it right the first time, create a mess in my small studio and get it over with.

So far, I am planning to use 1 sheet of 5/8 sheet rock and 3 tubes of green glue.  It would be great to use 2 sheets of 1/2 inch, but I'm not sure my mesh wire is going to be able to hold all the weight and I don't want the whole wall tumbling down.  Thanks for your help. 

P.S. I'm not sure how my building is considered a 'luxury apartment' when I can hear my neighbor sneezing, coughing and getting his booty calls next door.  Perplexed by NYC construction and the outrageous real estate prices.

Mark Daveis

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #3 on: March 08, 2008, 10:14:36 PM »
Two tubes of GG is plenty enough per board. But even with 2 layers of drywall and 2 GG layers you would only get about 5 to 10 stc.
I would doubt you would get anywhere near 10 as adding mass to a wall gives only a slight difference and you need to up the mass about 4 or 5 times to get a 10 stc increase but still GG will help with the LF sound.

I would go for the double wall approach myself. Why? Simply because when you set it up right then its like magic and you can easily get a 20 stc increase just by using 2 layers of drywall without any GG. I should know as I have built and tested them myself. Its a bit different here in the UK as most houses are built of concrete block or brick which have about 1 foot thick walls. The only houses that have framing and drywall walls here are the poor peoples houses! LOL. But joking aside even with one foot thick walls there is still enough noise problems going through it so the only solution is a double wall. :)

tacobar

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #4 on: March 09, 2008, 06:16:28 AM »
Mark,

Not sure I can add 2 layers of sheet rock on to my existing wall since I can't nail into studs, just meshwire.  I think at most, I can add 1 layer of 5/8 sheet rock, with a layer of green glue.   Otherwise, it's building a 1" frame.  If I go with frame, insulation, somate 440 sound barrier, 5/8" sheet rock - do you think that ought to do it? 

I'm surprised you can still hear your neighbors through concrete block or 1 foot thick walls.  They must be screaming banshees.  The only houses in America that uses 'concrete blocks' are prisons.  LOL!  I am the lucky ones, I live in a mid rise apartment building, and the floors & ceilings are made with solid concrete & steel beams, so I can't really hear my upstairs/downstairs neighbor.  It's just the bumbling twits next door. 

Mark Daveis

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #5 on: March 09, 2008, 10:53:55 PM »
Even with 2 layers you may not get that much improvement but high pitched sounds will be reduced but you may be just wasting money in the case of loud sounds and bass sounds. I would get a cheap sound meter and measure the highest decibels coming through on average and how much bass noise then decide which design to do. If the TV touches the wall then adding mass will have no effect as it will just conduct into the new mass added.

You need at least 2 inches of clear air space or the cavity acts like a solid with reduced performance but still will work and it just depends how much you need. Also 2 layers of drywall at least to get enough mass. Insulation only helps for HF sound. With 2 layers of drywall and GG you would get about 25 stc or more as I have done it with plywood myself.
Also check out the surrounding floor/roof and walls to see if they have enough mass or they could prove to be a weak link but they may be okay as you say.
But still more than 20 stc is a quite noticeable improvement but you will only get this from a separate wall plus air space.

The only thing that gets through the concrete is loud sounds like revving trucks but our double glazing in not too good at stopping noise as its low mass. But I live in a detached house so neighbor sounds are not the problem but things like motor vehicles, airplanes which can be quite loud. Most buildings are made with stone/brick or concrete in the UK and Europe since it plentiful and cheap but still some companies try to go even cheaper by using the same methods used in the USA just for extra profit. Yes prisons here are solid concrete and brick and built like bomb bunkers! :)


tacobar

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #6 on: March 10, 2008, 04:34:55 AM »
Hi Mark,

Good news, my neighbor moved his entertainment unit from our common wall.  Celebrating my small victory here! I think my building manager put the screws to him.  God bless you Tony, where ever you are.  Now, I don't really have a bass isues, I just have to deal with the loud chatter and screaming banshee gfriend, whom I refer to as 'Zena Princess Warrior'.  LOL!

I went to see my folks for Sunday dinner, and my Dad is willing to help me (he is also enlisting my Uncle who is a carpenter).  He proposed building a 2" frame, inserting insulation, then a layer of homasote 440 sound barrier, then 5/8 dry wall.   Do you think above should work if I'm only dealing with tv and noisy human beings?  Or should I go with 2 sheets of 1/2 inches and use GG in addition?  I am hoping the 2" cavity will help a lot.  I really appreciate your insight. 

It's nice to know that criminals live in better accomdations than I do!   ::)

Thanks. 

Vivian

Mark Daveis

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #7 on: March 10, 2008, 07:06:06 PM »
I know what you mean I have seen Xena on TV in the UK myself!
I don't know much about homasote but 2 layers of thick drywall and GG work quite well and you can even add a layer of mlv loosely attached behind the drywall to get more performance. 2 inches of air space is where good results start. You should get about 25 stc.
It really depends how loud they run the TV at but still 20+ stc is good.
The prisons are made very strong so there is no chance of escape and look like something out of the military with thick concrete and brick and huge walls and thick steel doors. So even a armed helicopter attack would have little effect sort of like a blast bunker. But this means really great soundproofing simply because of all that mass used.
I hardly think the prisoners are having a good time though being locked in a cell most of the day even if its quiet! :)

johnbergstromslc

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #8 on: March 10, 2008, 11:51:52 PM »
tacobar:

Before you go building a wall and making your apartment smaller, check out the Green Glue homepage at: thegreengluecompany.com

They have done extensive acoustical testing and should have something that approximates your situation.  You'll be able to quantify the improvement with the installation you're considering.  Shoot for STC 50 - at that level you shouldn't hear much from next door.  Since your neighbors moved the TV, you certainly don't need an 'overkill' wall (i.e. double wall) anymore.  And you'll be surprised how well GG works...

And whatever you end up doing, don't forget the sealing!  Seal under the bottom wall plate, around electrical boxes, anywhere the drywall has been penetrated and sound can leak through.  Odds are that the builder did no sealing. 

In fact, I'd recommend doing a thorough sealing job FIRST, before you spend dime one on drywall, studs or GG.  Then you can see how much of the problem was caused by a 'leaky' soundwall.   

tacobar

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #9 on: March 11, 2008, 01:01:18 AM »
Hey John,

I've read about Green Glue.  The thing I'm worried about is hanging 2 sheets of dry wall even if they are 3/8" thick.  I can't nail into studs, but rather existing drywall with wire mesh.  Not sure if wire mesh will support 2 sheets of drywall.   Do you have any idea?   Would you know the effect of just one sheet of 5/8 drywall and 1 coat of GG?  My building manager says I can do that.  My current wall construction is a 4" cavity in between my apartment and my neighbors.  It is followed by mesh wire, drywall (I was told double drywall but not sure) and plaster. 

Sorry, I'm a novice.  What do you mean by sealing?  Going around the electrical outlets putting a box into it and seal with acoustical caulk?  Pl. clarify. 

Right now, I can't hear the tv, just loud conversations, coughing, sneezing, etc. 

Thanks John.  You provide a valuable service to us all.

tacobar

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #10 on: March 11, 2008, 03:30:27 PM »
Hey John,

Just a follow up.  I was in the Green Glue website and determined the following. I think currently, my STC is 44.

Drywall Wall Assembly Tests (Wood Studs)
STC Source Side Studs Insulation Receive Side Test #
44
Two 5/8" layers of drywall, 24" OC, R13 Fiberglass, Two 5/8" layers of drywall OL 05-1059 

I can't detemine, if I add another layer of drywall, this makes 3 layers of 5/8, with 1 layer of Green Glue, what my new STC will be.  Any way I can determine if it's near 50?  Thanks!

V

Mark Daveis

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #11 on: March 11, 2008, 08:59:49 PM »
If you are already at 44 then 50 stc wont make much difference and I would say 2 layers of drywall would give you maybe another 5 stc.
But even a extra 5 or 6 stc is not much noticable in terms of sound reduction.
I would test it with a sound meter then decide how much stc you need.
Anyway let us know what sort of improvement you got after the design is built. :)

johnbergstromslc

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #12 on: March 12, 2008, 07:18:56 PM »
If, in theory, you should have an STC 44 wall and you're hearing normal voices clearly, then you have a 'leaky' wall.  I stand by my previous advice - focus on finding and plugging the leaks first.

ldjoner1

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #13 on: March 16, 2008, 01:46:26 AM »
Anyone ever use "quietrock" sheetrock for sound minimizing?

Mark Daveis

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Re: Soundproofing party wall in NYC Coop - Building Frame HELP!! SOS!
« Reply #14 on: March 17, 2008, 07:59:12 PM »
Quietrock works well enough and you can use much less mass than undamped mass such as drywall but you must have a proper soundproofing design or it wont make much difference. :)

 

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