Condo Sound Problem – Common Wall Soundproofing

Hi Ted, my name is J.A. I recently moved into a 2 story apartment in Connecticut and I am having issues with the sound. It’s a newer home that has a total of 3 apartments. My bedroom and master bath is on the second floor and it shares a common wall with a mirror image apartment on the other side. I don’t have a door to my room (I’ll take some pictures and send to you). It’s just a stairway up to my bedroom and it sort of has a “loft” feel to it (and since it’s the top floor, the ceiling has a lot of different angles). As you walk up the stairway, to your left is a common wall. It’s huge and I’ll measure it when I get home tonight. Once at the top of the stairs, the entire bedroom opens up to your right.

Here’s the issue, I hear EVERYTHING that my neighbor says and does. I can hear him walk, talk and even when he flushes the toilet! It’s awful. My landlord just last week installed some sort of sound barrier in the walls and put dry wall up over it. I’m also going to be buying an area rug for my room as well. But I know that wont be enough. My landlord said he will install a noise barrier in the wall in the other apartment next door as well. But to be honest, I am skeptical that’ll work. My neighbor is super nice and not loud at all. He’s having a normal conversation in a normal tone of voice and I can ever everything he says.

As an example: I have a walk in closet and its totally full of clothes, bagged comforters, shoes, etc, I even have one of those 2 tiered garment racks that are wrapped in fabric. So even will this small space full of dense materials that should absorb noise, I still heard the conversation he was having on the other side of my closet wall. I don’t know if I need to look into some sort of device that I hang on the wall, maybe one of those fabric panel looking things? I’m desperate for advice! Since my landlord doesn’t know a ton about architecture and soundproofing, etc, it would help for me to give him any sort of suggestions. I would really appreciate any advice and recommendations you may have.

Thank you!

J.A.

J.A.,

This sounds like a pretty severe problem and may take someone in the area who does work in soundproofing and acoustics to come have a look at it to MAKE SURE that you are taking the appropriate action and actually doing something to reduce the noise from one room to the other. If possible, I would throw something like ‘Acoustical consultant’, ‘acoustical analysis’ or ‘Acoustical contractor’ into a Google search with either your zip code or the name of a local major city. Give the first few hits that you find a call and see if they do site visits and what they charge. If the don’t, briefly explain the problem to them and ask if they know of anyone that can come have a look at it. There is a chance that this may be a fairly costly approach, but it MAY give you the BEST information as to where to start.

Common wall dwellings have to meet certain codes that are set in place by either the local building code or the national building council or code. There is a unit of measure called STC which is a rating of how “soundproof” a wall or ceiling is. The higher the STC number, the more soundproof. Usually places like yours must meet an STC of around 50 to be within code. It sounds to me like you are FAR under that, and it’s good to hear that your landlord is willing to work with you to improve it. Your landlord should have the blueprints for the building which will show HOW the common wall was built. I would be very interested in either seeing this or having someone tell me how this wall was constructed. This may provide the information needed so that I am able to tell you how to proceed.

In order to understanding how to fix a problem, one must understand the problem. Basically, sound travels via the path of least resistance from one room to the next. The first path is any kind of common air space like a heating/cooling duct or any crack that may exist. I would be surprised if this was the case in your situation, but it can’t hurt to look for something. The second path that it uses is the area of the wall assembly with the least amount of mass. An example of this would be if the drywall crew left a half-inch gap between the wall and the ceiling and filled the gap with foam or insulation before taping and mudding it. This, again, may be fairly unlikely, but any weak link in the wall would conduct a lot of sound.

If neither of these are present and the wall has an equal amount of density through out the wall and the wall, itself, is the issue, here is how sound works. When a sound wave hits one side of a wall it transforms into a vibration. The vibration travels from the sheetrock, to the stud – and into the sheetrock on the other side of the wall. Because it does not have any other hard surfaces to travel through, it becomes an airborne sound again. One very efficient way to stop the sound is to build two walls that don’t touch each other and are separated by an air space. This causes the sound to change forms multiple times, and every time it changes forms it looses energy.

Unfortunately, in cases like yours there are FAR too many variables to be able to say “Product X” will solve the problem, absolutely. Sound proofing is something that needs to be done quite specifically in order to be successful. This is why it is vary important to know exactly where the “weak link” is on the front side. With that said, I would strongly suggest at least looking at treating one side of the wall with the RSIC-1 Sound Isolation Clip. Unfortunately this system will require completely covering the existing wall with a new layer of sheetrock and that space will loose a little bit of overall square footage which is unfortunate, but this clip system is one of the most effective ways to block sound on the market.

The clip isn’t a sheet product like a vinyl noise barrier which may have been what your landlord installed on one side of the wall already. If this was put between two layers of sheetrock, it is very likely that it may not have made an audible difference which I can go into further if you would like? But, the whole intent of these clips is very quite simple. They are used to “float” a hat channel or a furring channel off of the studs and decouple (or separate) a wall assembly pictured HERE. It is just like building walls that don’t touch each other, but instead of buying new studs and loosing all that room, it floats the sheetrock off of the structure on one side only. It allows the sheetrock itself to move and vibrate (very slightly) and basically turn the vibration energy into heat.


4 Comments

  1. dessai

    I live on a busy corner of the road.I want a system which allows fresh air at the same time reduce noise from honking of cars buses etc.
    Can u suggest a system other than air-conditioning

    • Ted W

      Hey Dessai,

      Thanks for the question, but unfortunately there is not a simple, easy answer/approach. I will do my best to explain why.

      Sound travels through air – so whenever you have an airspace connecting the inside of the room with the outside of the room, that is the easiest path for the sound to get from point A to point B.

      To answer your question specifically, it would be theoretically possible to build some kind of air-exchange system that forced the air and the sound into some acoustically lined chamber, force it around a few (minimum of two) right angles and then out into the room. This is something that could be fabricated on site, like building a doghouse or stand-alone closet that would surround the air conditioner, but there is not existing product on the market to do anything like this.

      Please let me know if you have any questions or want more information. Thanks,
      Ted

  2. B Fran

    I own a condo & share a common wall and have gone to a huge and I mean a huge extent to get it soundproof using the following materials: acoustical insulation, green glue compound used between 5/8″ soundproofing drywall & using the green glue sealant on the outer edges, etc. of the drywall as well as sealing the electrical outlets with the green glue sealant. Well, I still have the same situation in which I hear the same & I mean the same noise from those individuals on the other side & it freaked me out BIG TIME! There is no use in telling you what I have dealt with over the many years; however, I need some guidance to stop this unforeseen noise. Will using acoustical wall panels help? I cannot seal the backs of the electrical outlets using quiet zone padding as these outlets are sealed within the drywall & at this time I cannot incur the cost. It is may understanding that the drywall around the outlets would have to be drilled out and then put the quiet zone padding in the back of the outlet & again I cannot incur the cost as I had to put in new cabinets, etc. So you can imagine my upsetting dilemma as I NEED SOME SERIOUS HELP ASAP as these individuals do not & I mean do not want to cooperate. Thank you for your quick reply and guidance as it is appreciated!

    • Ted W

      I’m sorry to hear about the existing problem, especially after you have gone through lengths to try and fix the problem. What you did not mention, though, was the type of noise that is bothering you. So, it is nearly impossible for me to make any sort of recommendation. My gut tells me that if you have gone through the lengths mentioned above and still have a problem that it is either (a) a bass or low-frequency issue, (b) an impact problem where the structure is physically shaking, or (c) a severe structural deficiency that would take significant engineering and structural modifications to fix.

      I can tell you that acoustical panels will not help you — they are used to control echo and reverberation within a space — they do not block sound. You might want to get an acoustical consultant or engineer into the space at this point.

      Sorry that I am unable to offer any more specific information. Thanks,
      Ted

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