i have a loft apartment (large, single room living space), which is nice - but this means that my common/shared walls with the neighbors on each side of me span the entire length and height of my unit. this means there is a lot of surface area for sound transmission.

the wall today is a metal stud with 2 layers of drywall on each side (my side / neighbors side). the floor and ceiling are concrete.

my unit is very long and narrow - since it's narrow, i really do not have much space to give up. however, i can give up an inch on each side - but no way i can build a new studded wall.

the issues i have is, i can hear dog barking through the drywall, and a lot of impact noises (eg, with one neighbor, both of our kitchens share the same common wall so cabinet slamming/impact noise transmits). i understand i can do very little about impact noises, so i am trying to reduce airborn noises by adding more mass.

i am thinking of installing either 1 new layer of 5/8" drywall with green glue to the existing wall, or 2 new layers of 1/2" drywall with green glue between each layer.

im thinking of doing the 2x 1/2" method, as that will give me 2 layers of green glue for dampening.

my questions:

1 - is there any other options i have (maybe for decoupling/clips?) that i can do without giving up much space? would it make sense to make do a 1/2-1" air gap and a single layer 5/8" drywall?

2 - is there any weight issues (structurally) i need to be aware of when adding so much extra weight to the common wall? eg, going from 2layers of drywall to 4?

i understand i am very limited in my options, but i think 2 layers of drywall with green glue between each layer will give me some benefit.

is there any other options i have? im realistically not looking to eat up more than 1" (2x new 1/2" drywall layers) from the common walls, but could give up 2" if there is added benefit.

thank you!

 

You say apartment - do you own it or are you a tenant?

Assuming you own and can do this, you'll have a lot of ancillary to do as well like extending outlet boxes and cutting and moving baseboard and other wall trim - you up for that?

 

Go to your local library and get a couple of books about constructing a home recording studio. You may find some ideas for sound attenuation that you can adapt to your situation.

I would start with a layer of Cel-O-Tex against the existing wall then go with one or more layers of gypsum wallboard on top of that. The cel-o-tex will help decouple the two sides. As you correctly surmise, it is wall mass that provides the most attenuation.

Oh, and what Mitch17 said.

 

im the owner.

the baseboard, etc is not an issue. we're already constructed a nice raised loft-bed with closet underneath (11ft ceilings give me some room to work with).

here are a few photos (you can see the loft-bed we constructed on the left, albiet it is unfinished in the photo (these are old pictures but should detail what im working with). you can see the LARGE surface area of the shared/common wall on the left.

http://i.imgur.com/jI1Ry.jpg



http://i.imgur.com/5eRkn.jpg



as you can see in the 2nd photo, the window at the end of my unit restricts me from eating up too much space away from the common wall - but 1" (2x 1/2" layers of drywall) should not be an issue at all.

my concerns are the outlets, as there is no way i want to dig INTO the shared wall and physically remove and replace the outlets to mount flush with the new drywall. however, ive been told that they make outlet extenders for such a purpose (to extend the outlet away from the wall based on however-much drywall thickness i decide to go with). the baseboard/wood trim again, would not be an issue at all.

also, what is the best way to butt the drywall up against the concrete ceiling? acoustic caulk? or do they make any sort of special clips for the ceiling to assist in decoupling from the concrete ceiling?

thank you !

 

I'm not sure what the correct term for it is but they make a corner bead that makes for a nice end on drywall. Basically the metal goes behind the drywall a little and then covers the edge to make for a nice clean edge. I would then caulk the edge [after the finishing is done] to the ceiling.

They are called box extenders, you find them in the elec dept of most big box stores - or any elec supply house.