Spray Foam Insulation to Reduce Shared-Wall Noise
March 6, 2016 2:43 PM   Subscribe

I own a small one-bedroom condo in a medium-sized building with no insulation. I can hear all of my neighbors (upstairs and next door) all the time. I don't want to tear down all of the drywall in my unit, and I've heard that open cell spray foam insulation can be used in finished drywall to help reduce noise. Does it?

The building was renovated in 2006, but they didn't install any insulation in the walls or the ceilings of the units. Upstairs I can hear a lot of stomping, repetitive video game sounds, and even phone conversations. New next door neighbor has a kid that constantly screams, in addition to being able to hear conversational talking, TV sounds, basically everything they're doing. I can hear upstairs neighbor's TV/phone calls at the same time as screaming kid/Spongebob. Neither one of them is at an unacceptable volume, it's just that the sound really travels because there's no insulation to block it.

I have seen some buzz on the internet that open cell spray foam insulation can be used for sound abatement in finished walls. This is the kind of foam where they drill a small hole in the top of the wall, insert a tube, and fill with insulation that expands. Instead of ripping out walls, there's just a small hole to patch. I would use a professional spray foam contractor for this, since I have zero equipment or know-how.

Has anyone ever actually tried this before? If so, was it worth the cost? Have you used it in a ceiling (I mostly see it for walls)? I don't need the noise completely eliminated, but I do want to know how much this would actually help.


*I am not looking for advice on how to talk to my neighbors about the noise. I'm interested in suggestions for things I can do to my ceiling/walls to help prevent their noise from getting to my apartment.

**I really don't want to tear out all of the drywall in my unit. I'd have to go through the condo board, hire contractors, hire a dumpster, apply for city parking permits for said contractors and dumpster, stay in a hotel during construction. It would be a huge inconvenience in addition to being really expensive, and honestly it seems like sound abatement is pretty tricky anyway.
posted by forkisbetter to Home & Garden (11 answers total) 3 users marked this as a favorite
 
How much sound reduction are you really looking for, in decibels? The spray foam isn't great, in my experience, but it's better than nothing.

Also, it won't help with the noise from upstairs at all. This guy explains why.
posted by SMPA at 3:08 PM on March 6, 2016 [1 favorite]


You should try several things before turning to the insulation. Weather stripping, decoupling points of connection, putting foam around outlets and electrical boxes, hanging curtains/baffles, etc.
posted by Cool Papa Bell at 3:12 PM on March 6, 2016


The walls are shared property of the condo: I'd be cautious about unilaterally adding something like insulation, spray foam or not. As for the upstairs neighbors, this is why most places require most floors to be carpeted.
posted by easily confused at 3:14 PM on March 6, 2016 [3 favorites]


A fairly cheap solution that I found helpful (I had a bedroom wall that adjoined next door's living room) was to line the walls with Ikea expedit shelves with the drona boxes and then fill them with clothes, towels, linen etc. It worked really well and was also useful storage. I believe it's kallax now instead of expedit but they work the same. I got the 2x2 ones stacked two high since I knew I wouldn't be staying there forever and they were easier to move.
posted by kitten magic at 3:28 PM on March 6, 2016 [5 favorites]


Consider "Green Glue", which you can find at Home Depot, and maybe also Lowes. You use it as an adhesive to bond another layer of drywall to the shared wall. I've heard good things.
posted by walkinginsunshine at 3:36 PM on March 6, 2016


Response by poster: I appreciate the suggestions, but I'm specifically interested in hearing about spray foam insulation (hence the title of the post) from people with first-hand experience with it.
posted by forkisbetter at 4:04 PM on March 6, 2016


I strongly recommend you hire someone who knows something about sound abatement and can help you devise a plan. This sort of thing is tricky and you can spend a lot of money for little result if you don't take the right path.

It doesn't sound like insulation will give you the most bang for your buck here. If you want to add insulation, I'd strongly consider blown in cellulose over open-cell spray foam as it is cheaper and denser. There have also definitely been issues with spray foam not completely filling cavities when it is applied through a hole.

You also definitely want to look at all openings in the walls and ceiling (electrical outlets, light fixtures, etc.) as potential sources of sound transmission. You should also consider adding a second layer of drywall bonded with Green Glue. For stomping sounds, insulation in the ceiling won't do anything significant at all.
posted by ssg at 4:42 PM on March 6, 2016 [5 favorites]


it can get complicated, but on the simplest level the key to sound deadening is density. ie. you want to fill your walls with the densest possible material. "dense pack" cellulose will be better (denser) than foam, and cheaper too. it is installed in much the same way. however, it's possible you could do it and not see a huge difference. it depends a lot on how your building was built.
posted by ennui.bz at 5:04 PM on March 6, 2016 [2 favorites]


No, spray foam won't help.

Sound transmission is largely a factor of mass and air-travel. Heavy things move slower, so they don't transmit as much sound, and it doesn't matter if they're gooey at any stage in their lifecycle. Sound travels through air, so sealing against air passage is also very important. If you really don't have any insulation in your walls, hire someone to install blow-in insulation, which can be done through keyholes cut into the existing drywall.

Sound within a heavy, sealed box can still be transmitted to things that it touches, so you can have a room with triple-layer drywall and green glue and mass-loaded vinyl in the floors, but the beams and joists are connected to the ones in your neighbor's walls and floor/ceiling. Sound travels through those connections.

Lastly, check your local building codes for sound regulations. Your condo/building may be out of code.

Lotsa variables, and the "how do i soundproof my thin-walled domicile" is among the oldest self-help questions on the Internet.
posted by rhizome at 5:23 PM on March 6, 2016


(on preview, guess I'm just duplicating what ssg said)

As pointed out, other spray-in things will be better and cheaper (cellulose, fiberglass, cotton). Foam is bad for sound because it cures hard and mostly acts as a solid thing for sound purposes.

Also, you need not remove the drywall you have, which would reduce your costs a lot. Once you have blown in whatever substance, you can put a second layer of drywall (with green glue) over the one you already have. Those two things (while paying attention to any openings; outlets, switches, etc) will block most of your adjacent neighbors sounds. The same thing to the ceiling will block the phone conversations, but won't lessen stomping by much. (Video game sounds depends on whether the speakers sit; in a TV mounted to the wall or on a plastic stand, will probably block quite a bit; speakers sitting on the floor, probably none at all).

Just doing the blow-in stuff will muffle sounds slightly from your adjacent neighbors and do almost nothing to the upstairs neighbor, sorry.
posted by flimflam at 7:17 PM on March 6, 2016 [2 favorites]


No, it is a very poor choice.

Open cell foam's density is too low, at about 0.5 lbs per cubic foot.

Dense pack cellulose is about 3.5 lbs per cubic foot. That is a significantly higher density and will result in much greater sound attenuation.

If you want to investigate this more, look at STC values of different wall assemblies.
posted by MonsieurBon at 8:22 PM on March 7, 2016


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