TM Soundproofing Soundproof Existing Walls & Ceilings

Soundproof Existing Walls & Ceilings

Topics Covered in this Article:

Read the article below if you find that you do not have the privacy or silence that you require in your you are in a condo, office building, hotel room or your own home.

For best soundproofing results you should consider removing your existing wall or ceiling and start the sound control process from your studs as detailed in our How to Soundproof article.

However if you prefer to keep your walls and ceilings in place and are content with a solid upgrade (about 6-9 STC points) then we have outlined the proper steps below.

(For more information on understanding how sound travels, see our Soundproofing Basics article).


For proper soundproofing you need to have some kind of absorption, usually that is accomplished by having insulation in your walls. To check if your wall or ceiling has any insulation in it, drill a quarter size hole in your wall and look in.

If there is no insulation you may want to consider pumping cellulose or loose fill fiberglass into your walls. You can usually rent the machine and DIY or have an insulation contractor do it. The process involves drilling holes in every bay and sticking a tube in and then pumping the bay full with either cellulose or fiberglass; there is no need to plug the holes as you will be covering the wall with another layer of drywall.

If there is even a little bit of insulation in the walls then do not bother blowing in the cellulose as it will get caught up in the old insulation and will not fill the wall properly.

Tip: Do not try to use any self expanding foams as these are expensive and not as effective as cheaper cellulose and fiberglass. In addition they will most of the time not fill your bays properly.


The next and most important step is to install another layer of drywall over your existing wall and ceiling. Our first choice is always to use 5/8 inch thick drywall, if that is not possible than 1/2 inch will do just fine.

Before installing, apply Green Glue Noiseproofing Compound onto the back of the new layer and then screw over the existing wall or ceiling as you would any standard drywall.

Applying Green Glue Soundproofing Compound to Drywall             Applying an Additional Layer of Drywall with Green Glue

How Much Do I Need? It is recommended to use 2 tubes of Green Glue on every 4 x 8 sheet. For more details see our Green Glue FAQ page, or Green Glue Installation Guide.

Now, depending on the noise type and noise level present, you may either finish your wall or ceiling at this point as described in the next paragraph, or you can proceed to install a additional layer of drywall with Green Glue over the 2nd layer (leaving you with 3 layers of drywall and 2 layers of Green Glue).

One of our suggestions here at Trademark Soundproofing is to have you install one layer of drywall with Green Glue and then wait about 10 days; if you are satisfied with the results go ahead and finish off the wall. If not then proceed to install the 2nd layer.

Soundwaves passing through ceilings

Important: When using this technique to soundproof a wall, keep in mind that if there is an open attic space above the 2 walls the sound will jump the wall and enter through the ceilings, see figure to the left. Even in places where there is no open attic space, sound can go over the walls through the air space above the wall that is created by the ceiling joists. This is especially true if the ceiling joists run over the wall from room to room.

The best solution for this is to install a 2nd layer of drywall with Green Glue on the ceiling in at least one of the rooms (preferably the same room that had the wall treated) in addition to treating the wall. This is a must if you have an open attic or crawl space.

Offices and Strip Malls: Usually have drop ceilings and the walls end at the drop ceiling with empty air space above the wall to the roof. This is a major cause of sound issues between spaces and treating the wall without treating the ceiling will not get the desired results. The proper way to soundproof these spaces is by building up the wall all the way to the roof line and treating the entire wall as mentioned above (Caulk all penetrations between spaces and top of the wall with Acoustical caulk).

If that is not possible building a drywall ceiling and treating it as mentioned above will work well.

When that is not an option either than you need to treat the ceiling with ceiling sound barrier tiles that are placed over each individual drop ceiling tile.


Applying Green Glue Soundproofing Compound to DrywallOnce you are done hanging your walls and/or ceilings, caulk the perimeter (the outer edge on all 4 sides) with a quality Acoustical Caulk. Be sure to fill the gaps fully, as a complete seal, with no air spaces.


STC Box Seal for Soundproofing Outlet BoxesYou can then spackle, tape and paint the wall as you would to finish a standard new wall. Seal all outlets in the wall with our specialty Outlet Seal.

The above described sound control technique has been used successfully by thousands of our clients, including hotels, office buildings and private home owners. You can do it yourself or hire a reputable drywall contractor in your area. There is no need for your contractor to have any prior experience in installing Green Glue. We will be happy to send you any materials you need and discuss any installation issues with you or your contractor.

[Keep in mind that this sound control technique is very good at controlling airborne sounds and some impact sound. However if your main concern is heavy footsteps or dragging of furniture then you will need to remove your ceiling and use one of our Resilient Sound Clips to create a floating ceiling system. Continue with installing insulation, hat channels, two layers of drywall with Green Glue as described in our How To Soundproof Article].

Click here to return to our Sound Control Homepage.

Copyright 2009 Trademark Soundproofing (Revised 2015). All rights reserved.


Customers Questions and Answers

1) Bill: I'm about to move into an attached house (row house). I'm not sure if sound proofing will work in this situation. There is a cinder block and brick common wall between the houses. The current sheetrock is on 1" furring strips attached to the sheetrock. I can sometimes hear music or conversation at a very low level coming through. I am not sure if it is coming up from the basement where there are some gaps in the wall that need fixing or over the ceiling. It sounds like through the wall. If I retrofit, then will the sound go away? Or is at so low a level now that it would be impossible to reduce it further? Is green glue, acoustical caulk and regular sheetrock enough or should I use Quiet Rock. thanks

Trademark Soundproofing Reply: Hi Bill, The GG is a very good performer on low frequency sounds, as in the ones that you are hearing. Being that you do not have insulation in the wall, performance is not at it's maximum. Standard sheetrock and GG will suffice. If you have an open air space above the wall than you would have to treat the ceiling too.

2) Sharon B: Will this green glue, one or two drywall treatment stop mumbled voices? That's what bothering us. Thanks for your help.

Trademark Soundproofing Reply: Hi Sharon, It would help for the sound that is coming through the wall (more so if you have insulation there, if not try pumping some cellulose there first).

3) Mark: What applying green glue and 5/8 drywall over a concrete wall. Will the green glue bond the drywall to the concrete wall without screws to hold it in place?

Trademark Soundproofing Reply:

No. The Green Glue is not a proper adhesive and should not be used as one. You would need to mechanically fasten the drywall to the concrete wall.

We also recommend that you use 2 layers of drywall on the concrete wall and apply the GG between them rather than between drywall and concrete. GG optimal performance is between layers of the same density.

4) Kevin : The noise from our upstairs has become more noticeable over the years. We have 2 bathrooms above our kitchen. Our kitchen ceiling has around 10 ceiling lights. What would be best method to dampen the noise? I am starting to think that the drywall is going to have to come down. Any ideas would be appreciated. Thanks.

Trademark Soundproofing Reply:

Hi Kevin, You are right about removing the ceiling. However it would only make sense if you plan on reducing the amount of recessed lights that you have there now. Consider switching to lights that can be surface mounted to the new ceiling.

5) David: I'm building a new house in which I need to provide room to room sound isolation between interior walls, to reduce television or recorded music sounds. My plan now is to use 2x6 walls with double 1/2 inch sheetrock on both sides and fiberglass batting inside. Using green glue between sheetrock layers and/or using blown in cellulose will cost more. How much benefit will I realize from them? Thanks, David

Trademark Soundproofing Reply:

Hi David, You will not realize that much benefit by using Cellulose over Fiberglass. However you will have a great benefit of adding the Green Glue about 9 STC points by adding it to one side and an additional 4 pints by adding it to the 2nd side.

6) JUDY : We have a finished dance studio and we need to sound proof it. We are adding more mirrors. Can we use green glue on the drywall and add mirrors over it?

Trademark Soundproofing Reply: Hi Judy, That would not help that much. You should consider adding another layer of drywall with Green Glue on the existing wall and hanging your mirrors on the new drywall (and we recommend doing the entire wall).

7) Debbie : In my retirement condo my neighbor with adjoining living room wall plays her music real loud. I have to turn my TV up almost double what I listen to then I still hear boom boom from the base. I hear her drop some items, of course nail pounding. The music is the most troubling for me. Is this expensive to hire out?

Trademark Soundproofing Reply:

Hi Debbie, If you have insulation in the wall adding a 2nd layer of drywall with Green Glue Damping Compound should drastically cut down on the low frequency sound of music.

8) Melissa: If we put green glue and then an extra layer of drywall over the existing drywall, how do we deal with any outlets/light switches boxes which would now be recessed by 5/8th of a an inch? Do we need to get an electrician to move the boxes forward or is there a less costly/easier fix? Also, what is the difference between using green glue and a sheet of drywall over the existing drywall, versus using a sheet of quiet rock over the existing drywall instead and what would you recommend for an upper floor ceiling, where there is access to the attic? Do we need to add a sheet of drywall on the ceiling, or can something be done in the attic to reduce the entrance of noise? Thanks for your help!

Trademark Soundproofing Reply: Hi Melissa, Usually the electric box can easily be moved forward, check with an electrician or search online. You can use QR, however according to some lab tests GG performs better. If the sound is from the room next door than either you have to build a wall in the attic between the rooms or treat the ceiling.

9) Lizabeth: I live in a town house and have a firewall and also blew in insulation and can her my neighbors all time. Running, jumping, music, voices and more. What is the best way to block out the noise from them? Thank you

Trademark Soundproofing Reply: Hi Lizabeth, Please read the article above. If you any specific question please ask it here. If would like to schedule a phone consultation (for a fee) please call our office to schedule.

10) Charlene: I needed to stop the footfall noise from upstairs that kept me awake at night. So, in my bedroom I attached 1 layer of drywall w/green glue between joists to bottom of subfloor, added insulation and MLV, Kinetics IsoMax resilient sound isolation clips, hat channel, and two layer of drywall with green glue between. I followed your installation directions, I nolonger hear the TV or voices, but now the sound of footfall from above is a deeper basslike sound that is more disturbing than before. its like im inside a subwoofer/bass drum when the neighbors upstairs walk. Why is that? How can I fix this so that I can sleep?

Trademark Soundproofing Reply:

Hi Charlene, That is a tough one. It may be caused by the MLV which is a thin layer and small space between that and the drywall. See our Triple Leaf Effect article. However I a cannot be sure about that without doing an actual site visit as you may have flanking sound issues down the walls or duct work. Thank You

11) David: I have loud neighbors who stomp literally all day and all night long and i never have a peace of mind. I installed fiberglass insulation above my bedroom and another layer of sheet rock. The noise is exactly the same. i understand that my condo was built very cheaply and not the right way. Is there anything I can do so i don't hear my neighbors? or is this just that way it is

Trademark Soundproofing Reply:

Hi David, You should apply a damping compound like Green Glue between the 2 layers as a minimum. If footstep sound is your main concern than you would have to remove the ceiling and decouple it using Resilient Sound Clips and Channel. However footfall sound is the hardest to eliminate and you cannot expect a full elimination of that (unless you start during the construction of the building).

12) David: Thank you for the response. Do you know any companies who use your products who can do sound proofing? Or someone who can come give me an estimate? Do you know of anyone who can replace ceilings?

Trademark Soundproofing Reply: Hi you can send us an email with your zip code. We have a database with contractors who are well versed with our products and consult with us. We will let you know if there is someone in your area that we can recommend.

13) Tom: What would be your suggestion to reduce noise between 2 bedrooms. Exterior walls & ceiling are all heavily insulated . Noise transfer between the two rooms is loud . Newer consrptruction wood studs, Sheetrock all smooth painted walls . Tiled floors, area rugs on a slab no basement. But every sound can be heard from master bedroom to bedroom next to it.

Trademark Soundproofing Reply:

Hi Tom. Are these 2 bedrooms under an attic or crawl space. If there is an open air space above the 2 rooms then you would have to soundproof the ceilings and the walls. Best way would be to add another layer of drywall with Green Glue in between,

14) Tom: Thank you for the response. Yes, there is an open attic over the bedrooms ( insulation is foam blown into joists) so the ideas suggested make perfect sense. Is there a simple way to deal with the attic ? Your suggestion on the green glue for the walls makes sense. Tom

Trademark Soundproofing Reply: We usually suggest adding another layer of drywall with Green Glue to the ceiling.

15) April: It seems your company favors the use of green glue. I have an existing wall to retrofit. What are the benefits over the use say of 1lb mass load vinyl sandwiched between sheet rock. Or could they be used in conjunction. Or is a third layer of 1/2 sheet rock preferable.

Trademark Soundproofing Reply: Hi April, That is correct as Green Glue will give you a better STC rating. If you want to use it in conjunction (which many of our customer do) you would need to add the MLV to the existing wall. Add a 2nd layer of drywall, add Green Glue and a 3rd layer of drywall. Thank You,

16) April L: I just reread the specs and noticed that green glue is not recommended for 16" center studs which is code here in San diego. Now I'm at a loss. Help

Trademark Soundproofing Reply: Hi April, Not sure where you saw that, please point it out to us. Most jobs using Green Glue are using 16 OC studs.

17) April L: I saw the data directly on the green glue site that testing was done with 24oc studs. A few other of your competitors sited this data also along with the warning that it is not recommended for 16"c studs.

Trademark Soundproofing Reply: Hi April, All sound manufacturers test their products on 24 OC studs as they get slightly better results than 16 OC (less connection points). Nevertheless in real world usage it is mostly used on 16 OC. The GG performs wonderful on 16 OC as all the reviews and our own installation can attest to that. I would be very curious to see a link showing a warning not to use on 16 OC as that does not make any sense. Thank You.

18) bob: we have a macaw and cockatoo and they scream up to 135 dbs they are in a 12x12 room finished. thought i would put insulation in interior walls, add a 2nd layer of 5/8 drywall with green glue. what else would you suggest

Trademark Soundproofing Reply: Hi Bob, You can add an additional layer of drywall with GG in between. So you would have 3 layers of drywall and 2 layers of GG. If you wanted to do something more extensive. You can remove the existing drywall. Add Insulation. Install Resilient sound clips and hat channel. On the channels install double drywall with GG.

19) Sara M: Hello! I'm researching how to do retrofit soundproofing for a residential renovation. It looks like MLV or Green Glue will be a big help. Is it effective to use them together? Or is that overkill and too expensive? I didn't see any tutorials about using them as an assembly, so I wasn't sure if it was advisable. I assume I would strip the wall to the studs, insulate as necessary, apply the MLV over the studs, then either apply a layer of gyp board with green glue or two layers of gyp with green glue in between. Thanks, Sara

Trademark Soundproofing Reply: Hi Sara. It is effective. The GG cannot be sandwiched with MLV so you would have to install the MLV first, then a layer of drywall, GG and a 2nd layer of drywall. If you are on a budget you can go with just the drywall and GG.

20) Sara M: Thank you! Do you have any charts or tables that quantify the benefit of adding the MLV to the gyp/GG sandwich? No big deal if not, I was just curious whether to advise clients to go the full monty (whether it's enough sound reduction for the extra money). -Sara

Trademark Soundproofing Reply: Hi Sara. We do not have a chart of the MLV with the GG. However testing on walls with MLV in there show a gain of 3-6 STC points. So you can assume a gain of about 3-4 points in a double drywall with GG system.

21) Jean P: In an existing shared wall which is concrete block structure (cbs), I hear both sound and closing of cabinet doors which are on the neighbor's side. The (cbs) goes all the way into the attic, but I also feel the noise carries over that space as well. My bedroom is next to neighbor's wall and hear all movement when the person closes cabinets, etc. Very frustrated as to what the best solution. Walls and Attic Space?? Please advise. Also can you recommend a contractor in Palm Beach County zip 33418?

Trademark Soundproofing Reply: Hi Jean. You need to soundproof the wall and ceiling as well if you have an open attic space above the 2 walls. You are best off with a stud wall and ceiling that has insulation and air space. Thank You.

22) Mary H: Hi ~ how many inches would this soundproofing detract from height of my home? Are there options here and what is the 'slimmest' option? I have new upstairs neighbors who are quiet noisy and I would like to soundproof my condo ceiling. Thank you Mary~

Trademark Soundproofing Reply:

Hi Mary. That would depend on which soundproofing method you wish to utilize. The thinnest possible is by using a 1 pound layer of Mass Loaded Vinyl which is 1/8" thick. That may not be practical as you would be left with a black vinyl on your walls/ceilings. Next and better would be to add a 2nd layer of half inch drywall with Green Glue in between. However if footstep noise is an issue you would really need to decouple your ceiling with Resilient Sound Clips about a 2 inch loss in space. Thank You.

23) Chris: Hi. I live in a rented apartment. I can hear my neighbor below snoring. My neighbor on the side is only connected by a 8x12 wall in the kitchen. I can not use most of the methods described. Adding drywall and such is not an option. I also have 2 metal doors. Sound comes through them greater than the walls. Do you have any suggestions for this type of situation?

Trademark Soundproofing Reply:

Hi Chris, You can try using a Soundproof Door Panel on your doors and Mass Loaded Vinyl for your Floors/Walls.

24) Gerhard S: Is it possible to get these materials in Canada? We live in British Columbia, on the west coast. Would you know a business here who does this kind of soundproofing? We hear heavy footsteps and squeaking of the floor above us and need to do something about it. Thank you.

Trademark Soundproofing Reply: Hi Gerhard Yes we ship to Canada on a constant basis please contact our sales department for details.

25) Zoe K: Hi, I live in a 1900 Victorian conversion flat on the ground floor. We can hear every step from our neighbours walking, banging, kids running and it's so load and vibrates. We are looking to find some options for us, either the whole flat or just the bedroom? What would your advise be?

Trademark Soundproofing Reply: Hi Zoe, If the noise is from upstairs you would need to redo your ceilings and crate a new ceiling using the decoupling method described in the article.

26) Anthony: I live near Toronto, Canada (Eastern Canada) and I was wondering if you have a Canadian distributor? I live in a townhouse with neighbours on both sides and this product seems to be a solution. I hear noises thru the walls from both of them. Thank you

Trademark Soundproofing Reply: Ahi Anthony, We do not have a distributor there at the time however we ship to Canada on a daily basis. Give us a call or email us and we will be glad to help!

27) Matt: I want to do a room within a room arrangement. The main room of the building has brick for the outer walls covered by plaster and lath. The ceiling is also covered in plaster. If I framed off half of the room to split it into two rooms, would I be able to leave a 1" air gap between the new framing and the plaster walls and avoid any triple leaf issues? Should I remove the plaster and lath and reframe, tear our the plaster above and decouple the ceiling? I can clearly hear footsteps above.

Trademark Soundproofing Reply: As long as you leave the the back of the framed wall (the side facing the exterior wall) exposed (i.e. not covered in drywall) you should not have any serious issue with the triple leaf effect.

28) Joe: I have a ceiling filled with Roxul insulation (2layers no air gap) & 5/8 FR drywall and still hear TV noise and talking. I do not want to take down drywall. Can I do resilient channel and another 5/8? or am I better off doing green glue and another 5/8 FR drywall? Thanks

Trademark Soundproofing Reply:

Hi Joe, you are better off doing a 2nd layer 5/8 drywall with Green Glue. We do not recommend a channel between 2 layers of drywall due to the triple leaf effect.

29) Sandra W: I live in the bottom floor of a stack condo. The neighbor above has a very heavy footfall. His dogs plays with hard toys for hours on end. They have hardwood floors. What can I do to help soundproof the ceiling from above? Any suggestion and who could do the work.

Trademark Soundproofing Reply:

Hi Sandra. Having your neighbor install carpet with our premium carpet underlayment would be your best choice.

30) liz: I own an exercise studio in a retail space of a shopping center. The tenet with whom I share a wall is unhappy with the audio bleed through that comes from our music. We've turned the music down and tweaked some of the bass from the tuner and it's still a problem. What recommendations do you have? And, might you have a referral for a company to come estimate the cost to soundproof? Thank you! Your website was so helpful. Liz

Trademark Soundproofing Reply:

Hi Liz. Thank you. If there is a drop ceiling on your space then it you would have to treat the ceiling with ceiling tile barriers. Additionally do your walls have any soundproofing? If not at least insulation and a 2nd layer of drywall with Green Glue would be the way to go.

31) Dennis F: I'm on the board of a condo association. We presently do not have any statement of required sound reduction for hard floor installation during remodels. The floor construction is a 4 inch lightweight concrete over 2inch subfloor of tongue and groove 6 inch plank which forms the ceiling in the unit below. We'd like to add language that requires the owner who are remodeling to provide adequate sound reduction. Do you have any suggestions for language that would be useful to provide direction on what would be reasonably attainable for remodels? Generally people are preferring to remodel with stone/ceramic tile products. Thanks, Dennis

Trademark Soundproofing Reply: Hi Dennis. Usually te terms STC is used. I.e. an STC of 50 and higher is required. For floors you would want to include impact ratings as well which is called IIC ratings. You would need to do some research to see what level you would want to require. One common issue with this is that we find contractors trying to reach a certai