Remove plaster for soundproof?
I’ve got a brick party wall with plaster applied directly to it, and it’s a sieve for noise. It is likely to have missing bricks from past intrusions, old gas lamp lines, etc. I’d like to remove all the plaster, fix the brick underneath it by replacing missing bricks and repointing, insulate the joist pockets with rockwool, and then cover back up with mass loaded vinyl, rockwool over that, and a quietrock wall in front.
The only problem, none of the soundproofing guys I’ve talked to are interested in the remedial work and only want to do the easy job of adding new material. I couldn’t bear the thought of investing money into this wall without fixing the source problem. Who should I call to get this done?
colonialrevival
in General Discussion 4 years ago
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28 replies
JoeBushwick | 3 years and 9 months ago
The quotes I received were for one wall about 9’h x 12’w. This is the party wall in a townhouse and the room is our primary bedroom.
Guest User | 3 years and 9 months ago
@Joe, thank you! Yes seems high. Was it for 4 walls and a ceiling? Also thank you for the guidance re using a contractor vs. a soundproofing co.
JoeBushwick | 3 years and 9 months ago
Replying to janedrew: I got ridiculous prices ($10K for one room) from specialty sound proofing contractors so I ended up hiring a handyman and we did it together. The job is not technically difficult and if you do your research and follow standard designs available online, any decent contractor should be able to do the work.
Guest User | 3 years and 9 months ago
@colonialrevival or @JoeBushwick can you share ballpark numbers that you were quoted for wall soundproofing? As well as how long it took to do the work? Thx
JoeBushwick | 3 years and 11 months ago
We had the exact same problem as you describe and I did much of the research with various contractors etc. At the end of the day, we left the plaster intact and did not pull up the floor. We did install mass-loaded vinyl, new metal studs, rock wool insulation and two layers of 5/8″ sheetrock with Green Glue between the layers. This made a huge difference. We only did the work in one room so we still get sound coming through other parts of the party wall but in the room where we did the work it is so much better.
Guest User | 3 years and 11 months ago
I don’t have any issues with using the forum as a starting point or for discussion, that’s what it’s here for. As you said one must read, research talk to multiple people and then figure it out. Relying completely on the forum or one pro is not always a good idea.
andriywww1990 | 3 years and 11 months ago
jane, in short there is a way to sift through it. if i were doing this in my house, i would not call the firm you mention but would be reading a lot and asking questions of the people who sell the products. and after talking to them, i would read more to see if i can discount what they are saying. you are correct though, if OP is not interested in this stuff and does not want to read this stuff, op would be wise to follow your advice.
there are ways to “manage” this stuff and these projects. one way is to call a pro. the other is to do a lot of research and we often did both in buildings. i still check behind what people tell me and as you now know, people on this board would be wise to do that with everything they hear on here. A board like this can serve as a good “starting place”.
Guest User | 3 years and 11 months ago
Steve, yes some could research it and spit it out and is a risky practice Being burned here by exactly that, I’ll not be following that practice. Not everything you read is comprehensive enough and one will not glean as much as having had actual experience and facts. In situations like these I prefer to direct OP to contact an expert.
Even if I have done it a few times, there are often limits to advice that can be given online without understanding/knowing the reality.
colonialrevival | 3 years and 11 months ago
@janedrew yes! Kevin has been very helpful, as well as Ned from Hush Soundproofing who we will likely be contracting out for the big chunks of the job. However, neither of them have wanted to go under the floorboards aside from some spray insulation foam where the wall meets the floor. I understand this, it’s far easier to soundproof from below, but we have some ornate trim on the floor below that would be best to leave undisturbed. After some investigation today during another chatty session next door, the flanking noise coming through the floor (thus the joist pockets) is most pronounced as we can hear everything they say crystal clear. I know that isolating the party wall will be huge in soundproofing gains, but I was always taught to do it “all the way, and the right way.” In that sense, to leave the source of the issue untouched, and add material that makes it even harder to address later, would be a mistake.
I’m placing some orders today to test a section i n another room that already has easy access to the joists (via our basement) and will report back with my findings.
andriywww1990 | 3 years and 11 months ago
op, what you are trying to do is “decouple”. use that term along with sound transfer and perhaps “attached house” or “row house”.
andriywww1990 | 3 years and 11 months ago
so i also googled this term: “joist hangers to isolate sound” and if i googled it again i would use ” isolate or stop sound transfer”. this just returned all sorts of results offering up all sorts of brackets from several companies.
if i were doing this in my house, i would not be calling anyone in. i would be reading and reading and might talk to someone along the way and would read more. it helps to have a basic understanding of wall and floor and ceiling construction, but that is easy. you can research this just as good as anyone else on here can.
some of these things these people advertise may be very similar and the choice may come down to one thing: cost.
andriywww1990 | 3 years and 11 months ago
colonial, in truth, i really don’t want to learn anything new about interior construction and not anything about sound transfer. its too scientific for me. But since no one else is posting anything today, i just googled “floor joist sound isolation” and returned something from the “soundproofcow” that someone mentioned above. they are “floor joist isolators” that look like the cap over the top of the joist and from there someone sets the sub floor. the guy i spoke to years ago said there was a way to isolate the floor. and ceiling.
if you have already found this stuff i am posting but were not sure of the application, ask. some of us (me included) know enough about elementary wall construction that we would know how and where these things might go.
i am going to go back down stairs and will keep reading. i am sorry, it will come in multiple posts.
andriywww1990 | 3 years and 11 months ago
jane, even if some people are not contractors, it would be ok if when they commented that they would admit that they “heard it somewhere” or “read it on the ‘net”. especially here with something so specialized as this that few of us (not me) have done. if urbandad were here he would research the answers (anyone of us can do that) and spit it all out on here without admitting he has never done it (there are ways some of us can see through what he is doing, certain language and the “breadth” of the knowledge; unless you do something everyday, you begin forgetting things even if you did them everyday twenty years ago). its sort of a slap in the face to people who work and have had to learn over time by doing.
op, it sounds like you have to call someone who is engineering this stuff here in the city, because of the joist pocket issue in the old attached houses. the link jane provided.
i recall enough of what the engineer i spoke to said about how to d o this to see if i can run this down on the ‘net and post a link here. i recall “what” he said had to be done, but do not recall “how” he said it is done. if i find a link pertinent to city houses, i will post.
Guest User | 3 years and 11 months ago
Have you called https://www.brooklyninsulation.com. I’m not sure if everyone we think is a contractor is a contractor on this forum. Some are just knowledgeable but may not know specialized things such as this. It isn’t a common renovation ask though it should be.
colonialrevival | 3 years and 11 months ago
Green glue doesn’t seem to be highly regarded among professionals I’ve spoken to when compared to something like mass loaded vinyl. A source I found (in the UK) recommends filling any gaps in the party wall joist pockets with a dense spray insulation, and then peeling back a few floorboards, and filling the gaps between each joist with 5lb/ft^3 dense rockwool based insulation. Will continue research, finding more luck with UK sites since their housing stock compares nicely to ours.
andriywww1990 | 3 years and 11 months ago
“green glue”. it is a semi solid caulk that could be laid down on say the joists and the sub floor would be put on that or perhaps the green glue is laid over the old sub floor and a new subfloor over that and the glue isolates the wood, breaking transmission. i just googled green glue and they have a website. check it out. (keep up the research; pretty soon you will know more than urbandad and i am surprised he never mentioned it here; i did not mention it in my post above because i have never used it and it sounded “gimicky”).
perhaps someone on here has used Green Glue. i seem to recall someone mentioning it here years ago, like over a decade. or did the accoustical engineer i spoke to mention it?
(restoration contractor is a full on contractor and has probably done this, urbandad is not a contractor but is good at internet research and regurgitating what he finds on here without admitting he has never done a lot of what he talks about himself or giving credit to where he read it; it sounds like urbandad has “properties” and that means he has not been spending loads of money and time trying to isolate sound in coops and condos).
colonialrevival | 3 years and 11 months ago
Just getting back to this. I’ve received from pricy quotes from some soundproofing experts, many of which involve layering mass loaded vinyl over the plaster, furring out a new wall, filling it with rockwool, and layering sheetrock and mass loaded vinyl over it. This sounds like a great way to isolate the wall, and I’m just about ready to go for it.
However, I’ve read lots on here and elsewhere bout how sound also travels through party walls between joist pockets. I’ve _really_ done my due diligence with Googling, however a joist pocket here differs from a joist pocket in the majority of other fully detached American suburban homes. Should I be opening up the floorboards and ceiling before building this wall? If I were to do so, what’s the best approach to slow sound transmission in these areas? My initial inclination would be some form of insulating spray foam, followed by a thick and heavy insulation (probably more rockwool).
I’d be curious to hear from some of the contractors on here (UrbanDad, RestorationContractor come to mind) what their approach to this is — I d on’t want to go on a wild goose chase, but it’d be great to fall asleep at night without listening to my rambling neighbor’s phone conversations.
andriywww1990 | 4 years ago
i once did what jane did and called an accoustical engineer located on St Marks in the city. and like what jane says, the guy spent a lot of time explaining all this and did not try to sell me anything. i wish i could find his name, i would post it here. he told me that most sound travels along the wood joists and into the pockets and into the wood in the neighboring apt, which is why you are hearing it when they are down below, it passes their cieling into your floor, i suppose.
the guy i called at all sorts of solutions and more involved isolating floors and ceilings with all sorts of materials i know nothing about. the walls were less of a concern.
colonialrevival | 4 years ago
Just from the adjacent floor primarily, though we do get occasional sound travel when they are loud downstairs.