Dear PoP – Does anyone have any tips on soundproofing?

by Prince Of Petworth December 22, 2010 at 2:30 pm 1,075 31 Comments

Photo by PoPville flickr user DCityDude

“Dear PoP,

I live in a 115 year old townhouse and rent out my basement apartment. Nobody is overly loud or plays music or TV above a civil level, but we can still hear each other through our floor/ceiling at normal volume talking voices. Although our tenant has never complained I’m sure she must be annoyed by our dog running around our place chasing his bone and us walking on wood floors. We have our floors covered as much as possible by area rugs to help with the noise, but we can still hear her and she can surely hear us. We like our tenant and don’t want her to be chased away by our noise. Also, after living in apartments for several years and recently moving to a house my wife and I would prefer not to hear our neighbors.

I’m wondering what our options may be for soundproofing an old row house. The wood floors are original to the home so tearing them up is not an option. In the basement apartment there are drywalled ceilings that likely are screwed directly to the joists. I’m not thrilled about the idea of tearing through the basement ceilings to add some sort of soundproofing materials, but I am starting to think this may be my only option. One other important thing is that my ceiling height downstairs is just above 7ft (the minimum required for my CofO) so I can’t bring this any lower. Do any of your readers have any tips for me that don’t include turning up the volume on my own speakers? Any ideas for good contractors if I must replace the drywall and add soundproofing?”

Some options were given back in Jan. ’10. Anyone else have good suggestions?

Comments (31)

  1. Annoyed by banging headboard

    I can hear my neighbors head board hitting our common wall all the time. When I first moved in, I had no idea what it was. Eventually I made a connection, due to time of day and pace of banging….

    While renovating a bathroom that shares this common wall, I put some insulation in while furing out the wall. It didn’t really help. It was a dense insulation too.

    Anyway, would be interested to hear.

  2. Drop ceilings, and install ceiling panels. We did it in our basment apt, works great. Buy them at home depot, takes a few inches off the ceiling in the basement.

  3. Eww, ceiling panels, really? No one wants to go home and feel like they’re still in the office.

  4. Gross – Beside the OP has no inches to spare.

  5. Worst idea ever. lol

  6. If you find out anything let me know. I live in a row house and can hear my neighbors laughing and talking at a normal level.

  7. Blown in cellulose. The insulator will drill a hole (3 inch diameter or so) through the ceiling drywall in between every joist and blow it full of insulation and plug it, likely with a wooden plug of equal size. You can then either paint over the plug, or spread a thin layer of drywall compound over it to smooth the edges.

    It shouldn’t cost you more than a grand for the insulation, assuming you have a typically sized rown house and floor plan, it will cost more if you hire a contractor to patch the holes rather than doing it yourself.

    The result is amazing. Cellulose is a great sound absorbant material and the blown in application is easy as pie.

  8. And your wood framing will rot because the blown-in insulation traps water vapor which condenses into water. Dark + water = mold + rot. Blown-in insulation is for new construction.

  9. No, not really. Only if you have a vapor barrier installed incorrectly, you have a leak in your pipes that goes through your insulation, or a leak that enters your insulation.

  10. And that’s why I make tons of money fixing blown-in insulation disasters. So actually yes, please blow insulation into your old house. Then call me in 5 years.

  11. The truth is that to actually make a worthwhile improvement, it WILL take major construction… AND even then you’ll get no guarantee from any contractor that it will elimnate the sound. It’ll be a gamble.

    No cheap $1K projects or blown insulation will solve the impact sounds of shoes, chairs, dog bones, etc on floors. It may help a bit with voices, but sounds will conduct through floors, joists, wall frames, etc unless there is something to absorb it at each level.

  12. Completely false.

    No one is saying that you are going to 100% eliminate the floor noise between basement and first floor, or that you’ll be able to turn it into a recording studio, but speaking from personal experience, the blown cellulose eliminated 50% of the noise and muffled the rest to the point that it was no longer so noticable.

    Well worth ~1K and satisfactory until one decides to build themselves a concrete framed house.

  13. How can my answer be COMPLETELY false when your solution admittedly only eliminates noise 50%?

    The reason sound-proofing is such a tricky topic is because everyone’s current contruction, budget for reno, and noise tolerances are different. I’ll state again that from my experience, blown insulation WILL NOT work for impact noise under any scenario, due to sound vibrations traveling around the insulation via the framing. It’s basic physics.

  14. Blow-in cellulose is terrible idea for a couple reasons. Cellulose is a thermal but not acoustical barrier, at least not an effective one. So far as I know, a dense blown-in material does not yet exist. I’ve had subs use mineral wool w/ some success and it also serves as a terrific fire barrier (heat capacity of over 1500 degree).

    The second reason you don’t want to use a blow-in in the situation described is that in a basement you need to maintain easy access to pipes and electrical wires, should you have a leak or need to run new lines.

    This is one reason drop ceilings are so popular in renovated basements – in addition to affordability, they provide easy access to essential spaces. you may want to research a drop ceiling, as I believe there are a number of new lines out that don’t look like your traditional office space.

  15. I think that if you’re so lacking in the sound barrier, you probably also are lacking a fire barrier. I think you probably need to pull down the ceiling dry wall and add some sound/fire barrier. Each layer is only a fraction of an inch thick, so you shouldn’t have a problem with losing height. Plus, it will protect both you and your tenant from fire in the opposite unit.

  16. A 10 penny nail through each eardrum.

  17. That gave me the chills.

  18. I actually started off the question last year. It was horrible, I could hear everything, the only thing that changed it was moving, I bought on the top floor this time ha-ha. Things that could help tremendously though are 1. not wearing shoes in the house 2. Wall to wall carpet with heavy padding under it 3. Finding a level that your audio / tv is set to that they can’t hear and keep it at that level. 4. Sliders on the bottoms of kitchen chairs or a carpet under the table 5.The dog has got to go, nothing can stop that : )

    There are some things that can be done but it is expensive, there is a membrane that can be put down under your carpet to help and there is a sound deadening system of special drywall, a special sound glue and clips to reduce the transfer of sound. These two things together work quite well but are expensive. Consider how cheap it is per day of quiet happy peace and it looks VERY reasonable.

  19. There is a guide to soundproofing I bought here:

    Its very technical, but very informative.

  20. I’m in a row house that was converted (cheaply and poorly) into a condo. I could hear my upstairs neighbor very easily because there was no insulation between us. So I added a second ceiling in my bedroom. The metal framing around the heating ducts was also loose.

    My contractor cut into the ceiling and wall and secured the metal framing using chopped up inner tubes as washers. He put insulation made from denim (apparently best for sound insulation) around the ducts and in the space behind the dry wall.

    Then the contractor installed a second ceiling. He cut into the first ceiling to drill screws from below to address squeaks. Then he installed denim insulation above the first ceiling best he could, and below it.

    The new ceiling is held up by “hat track.” It’s basically a bunch of hangers. If you screwed the dry wall directly into the joists, the noise from above, particularly things like foot steps, would be transferred to the dry wall like a drum. The hat track creates enough of a separation to cut that down.

    The result? Much, much better. I can still hear my upstairs neighbors but not nearly as much and my wife and I can sleep through nearly all the noise.

    Unfortunately this contractor has moved away so I can’t recommend him. This isn’t something most contractors do. We had to improvise quite a bit and be creative. But that’s life in an old building!

  21. I did quite a bit of research on soundproofing because I can hear everything above me in my condo. It’s an old row house with 4 flats essentially. I would recommend contacting Accoustical Soultions in Richmond, VA.

    I soundproofed the master bedrooms ceiling and was going to do a similar, but more involved project in the second bedroom which I rent out. Due to a sprinkler system installed in our condo however, it would have been more work than I thought worth it. I would have had to have the sprinkler head extended, which would have involved draining the entire buildings sprinkler system ($600 extra at least).

    In the master bedroom I simply installed a new layer of drywall over the existing ceiling with green glue, an insulation material, in the middle. This did quite a bit to take care of the problem, but didn’t completely take care of it. Reason likely being that the dry wall is still connected to the wall which is still connected to the neighbors walls above me, which is connected to their floor, the source of the sound.

    When I contacted accoustical solutions for the second project, they recommended installing tracks w/isolation clips on the existing ceiling, applying the green glue and then installing the new layer of dry wall, but leaving a space between the wall and the new ceiling to be filled with an accoustical cauk (sp) along the edge. If I would have used the cauk on the first project, it would have provided a barrier between the wall and ceiling and absorbed even more sound waves than just installing the green glue. It was like my 4th phone call to them that I figured that part out. (Like I said, I’ve done a lot of research on this.)

    So, basically, you can buy all the products, and then install a new ceiling over the existing ceiling. I dont know how much that would help with sound traveling up (from the rental unit to the house) but it should help with sound traveling down, or footfall. Again, my challenge was that I didn’t have 2 or 3 inches to remove from the ceiling for the second bedroom due to the sprinkler system, otherwise I could tell you how well it worked. Like I said, the first project made it much better, but didn’t make it perfect. As far as cost, the green glue cost me approx. $100 for a box and then I had to pay for the installation of the new drywall.

    Oh, and the benefit of going this route is that you dont have to remove anything, you just install over top of the existing ceiling.

    Hope that makes sense, let me know if you have any questions and I’ll send Pop my email address so you can be in touch.

  22. It looks like Cookietime has basically the same recommendation as I did, the hat tracks. Check out accoustical solutions, they have several documents that explain the track system on their website.

  23. Has the tenant complained? How do you know it’s actually a problem?

  24. I first realized how easy it was to hear between the floor when I had a heating contractor out to fix the boiler. He was in the utility closet and I was on the ground floor at the thermistat speaking to eachother in normal voices.

    Also, I can hear her and her music.

    Thanks everyone for your suggestions. I will be looking into several (except for the nail to the ear drum one).

  25. I can second the Acoustical Solutions folks, but prepared to pay. If you care to do it yourself, it isn’t terribly complicated, but the proper materials are essential.

    1) Mineral wool acoustical insulation to insert between the joists (despite what someone suggested above, blow-in insulation and fiberglass don’t have acoustical property b/c they aren’t dense enough. They are primarily THERMAL barriers, rather than acoustical. Mineral wool serves both functions.) You can purchase vats of it at Capital Building supply. Just be sure to know the measurements of your joists and to buy at least 6″ thickness).

    2) Resilient panels to attach the drywall to ( Don’t make the mistake of attaching the drywall directly to the joists, as that as one of main vehicles for transmitting vibrations (noise).

    3) Quiet Rock drywall ( – acoustical drywall w/ 5X the deafening of standard drywall (also 4X as expensive per sheet). Terrific stuff and even easier to work w/ than ordinary drywall.

    Now if the basement shares HVAC ducts the main floor, this makes an extra hurdle and one you may want to call a professional in for.

  26. ^ Winner. As a contractor, I concur with everything Nate said.

    Technically, too much density is the reason joists carry sound so well, but it’s true that Roxul (mineral wool) would deaden sound much better than cellulose. In all other respects, I’m a huge fan of cellulose. It’s made from recycled newsprint, it has a higher R-value per inch than fiberglass, it’s non-toxic, itch-free, pest-resistant, inexpensive, and flameproof (fiberglass ignites whereas cellulose just smolders when a flame is held to it). Good stuff.

  27. Acoustiblok ( a flexible product that goes on before drywall so you do not have to worry about the vibrations from the 2 by 4’s. The way this stuff works is it takes the sound vibrations and changes it to a thermal energy.

  28. I can so related. Had this problem in the past and used quietrock drywall.

    It is a product that looks like drywall but is way more dense and is installed on top of your existing ceiling. The soundproofing is like adding 10 sheets of drywall, so it is not 100% soundproof but pretty close. Each sheet costs a little over $50 a sheet (compared to drywall which is like $8 a sheet) but still well worth it for the results.

    If you have any questions, call me as I have used this number of times 202-506-0019.

  29. I share no walls

    Ha, I don’t have to deal with noisy neighbors because they don’t share any walls with me. Just buy a single family home and you’ll have the best sleep every night.

  30. We build a lot of condos and we’ve used several different methods for soundproofing. We find the resilient “hat channels” on the ceiling below and then a soundproofing membrane (like Homasote) above under the hardwood floors works best. We’ve also had good experiences with Green Glue between two layers of sheetrock.

    In our condo project at 1470 Chapin St NW, we just installed the hat channels last week. You can see them in the second pic down here:


  31. I thought I could wing some common sense advice, but then I got out an old building engineering textbook. Conclusion: accoustics iz hard, has lots of graphs, and way too many greek symbols.

    First lesson: you have to know if you want to block high frequency noises or low frequency. A material good at blocking high frequency might not be good at low frequency.

    Another nugget: “absorption is not always proportional to thickness, but depends on the type material being used and the method of installation. Little is to be gained by adding thickness except at very low frequencies, or when installed discontinuously.”

    And: “In increasing order of effectiveness, absorbent material can be applied: 1. directly to room surface, 2. hung below ceiling and supported away from the walls, 3. hung from the ceiling as louvers or baffles, 4. made up into shapes such as cubes, or tetrahedrons, and suspended from the ceiling.” The last two are all about disrupting and reflecting sound waves (I think) and partly explain why coffered ceilings in Metro and eggcrates in ghetto recording studios work so well.

    Not to mention: “To obtain good low-frequency absorption, it is essential that a deep air space be provided behind the porous absorbent material, and that walls be treated in addition to the ceiling.” So look to the basement tenant’s walls. Treat them too with absorbent materials so sound waves don’t bounce all around the basement and then through the floor. Deaden them before they get to the ceiling.

    And completely counter-intuitively: “Fibrous or porous materials absorb by the frictional drag produced by moving the air in small spaces within the material. The absorption provided by a specific material depends on its thickness, density, porosity, and resistance to airflow. Since the action depends on absorbing energy by ‘pumping’ air through the material, the air paths must extend from one side to the other. A fibrous material with sealed pores is useless as an acoustic absorbent. (Therefore, painting will generally ruin a porous absorber.)” Which explains why the acoustic ceiling tiles in my childhood schools had all those holes in them, and why they never painted them. And I thought they were being cheap. That also explains why blown-in insulation does nothing, but rock wool insulation does something.

    Bottom line: Call those accoustic engineering geeks referred above.


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