MLV vs Green Glue

[deemer76]

I'm looking to soundproof a party wall in may apartment. I constantly hear my neighbor's TV and radio, along with other bangs and thuds here and there -- but it's mainly the continuous sound of the TV and radio that annoy me. So I'm looking to soundproof that wall. The building was built in 1964, and the walls are plaster. Tearing down the current wall is not an option, which leads me to ask a couple of questions:

1. Which is the better option: Green Glue in between my plaster wall and a new layer of sheetrock or attaching MLV to my current wall with a layer of sheetrock? (Also, if necessary, I'm willing to do two layers of this -- so, my plaster wall, GG, sheetrock, GG, sheetrock.)

2. Does it make a difference that the Green Glue would be between one layer of sheetrock and one layer of plaster?

3. I know that ideally, the MLV should not be sandwiched between two walls -- that it should be more free-floating -- but how much less effective is it really when between walls?

Any help, any advice would be terrific. Thanks!!

[Skip]

Here are some suggestions. First put up a layer of 1/8" thick Mass Loaded Vinyl over your existing wall. Use either pressure sensitive adhesive backed MLV and stick it right over the wall or use plain MLV and power nail it thru the wall into the studs. Then put  up strips of Green Isolation tape 1-7/16" wide  over the studded areas. Finally, put up a new layer of 5/8" dry wall.

If you do not get the results that you are  looking for, then put a layer of Green Glue over the wall and another final layer of 1/2" thick dry wall.

Green Glue comes in quart containers and one should use 2 or 3 tubes for each 4' x 8' sheet of dry wall.

[deemer76]

Thanks for the reply. So are you then saying that MLV is a better alternative to GG? It's all so confusing and conflicting, bc GG's site has studies showing GG's superior efficacy to MLV and other materials. I'm sort of undecided on which to get. Obviously GG is considerably less expensive and the installation process is a little easier. But I want to know that it will work too. I'm skeptical that a glue will work, but I've spoken to many acousitcal people at other companies (admittedly compeititors to this one -- but you all basically sell the same products), and they've recommended GG.

Will my results really be better with the MLV? And TV and radio tend to be at lower frequencies, correct? Isn't GG supposed to be better for that? Please advise. And thanks again!!!

[Skip]

As far as costs go. if you use 3 tubes of Green Glue for every 4' x 8' sheet of Dry Wall, you will have approximately the same costs.

Green Glue is a dampening agent as MLV is a Barrier Material. The Green GLue requires two layers of Dry Wall.

The MLV can be put on over exposed studs and covered with one layer of Dry Wall.

Both approaches are modern and effective in the control of sound.

The MLV give immediate results, the Green Glue can take anywhere from two weeks to a month to provide optimum results.

[deemer76]

Can't green glue go in between my current plaster wall and a new layer of drywall? Or does it HAVE to be between two drywall layers. I'm jsut wondering why there would be a difference, if there is one. Thanks!!

[Skip]

Yes it can as long as the plaster wall is pretty smooth.

[deemer76]

The wall is definitely smooth enough. One last question -- for now, at least -- does it make a difference at all that the current wall I have is painted. I think I read somewhere that in such cases, the GG should be applied to the current wall instead of the drywall first. That would make installation a bit more cumbersome and messy. Can you please clarify? Thanks!

[johnbergstromslc]

You might be surprised how 'unsmooth' plaster really is.  The constrained layer damping effect works best when the outer panels are equal in density and isotropic (same characteristics in every direction).  Also, unlike drywall, the plaster will develop cracks over time, which will nullify some of what you're trying to do.  It's a lot of work, but 2 layers of drywall would work best.  This would also give you the opportunity to open up the wall, do some needed sealing and put some insulation in there too.

For more detailed information, I suggest you shoot an email to Ted White at the Green Glue company (greengluecompany.com - go to 'Contact Us').  I've emailed him a couple times and he's the ultimate source on the subject.  Who knows, maybe applying over plaster is not an issue.      

They only sell GG by the case, so for a small job like one wall, it's better to buy from supersoundproofing, where you can get it by the tube.  

I'm sure it doesn't matter if the current wall is painted.  That Green Glue is sticky stuff!

[deemer76]

Thanks, I actually e-mailed Green Glue Co. right after I posted this message. I'll see what they say.

As for opening up the wall, that's just not an option. I live in a Manhattan co-op. Who knows how they'd feel about that. However, I suppose it is possible for me to attach a layer of drywall to my plaster and then green glue, and then drywall again. Not something I'd ideally like to do. Or perhaps better still, I can apply green glue to plaster wall, then dry wall, then green glue again, then drywall. Certainly ups the cost a bit, but perhaps that's a consideration.  

Oh, and the wall I'm looking to do is about 140 sq ft. One case is preetty much exactly what I need for one layer (if I use it all , it would come to somwhere between 2 and 3 tubes per sheetrock, so that works out)> needless to say, this is all very stressful!

[johnbergstromslc]

Adding 2 additional layers of drywall would be good too - you'd triple the mass of the wall and with the Green Glue layers get some pretty good sound reduction.  Maybe that's your best bet.

But keep in mind that sound has other paths to travel.  You might have to address the floor and ceiling too.  

[Skip]

According to the manufacturer of Green Glue, as long as the painted or wallpapered surface of the wall is properly bonded to the wall, the use of Green Glue on that wall is proper.

[SueBee]

John,

You say in your December 12 post, "But keep in mind that sound has other paths to travel.  You might have to address the floor and ceiling too."  Is there anything that can be put around the top/sides/bottom of the drywall to help reduce any traveling noise to fill in any gaps that might let sound through or would a person have to actually soundproof the floor and ceiling too?  I'm thinking about having one party wall of my townhouse done with MLV and green glue and just wondering if I can "easily" address the flanking noise too.

Thanks,
SueBee