Soundproofing an Office Ceiling


I found your website and it has been very helpful. I’m hoping you can help us select the right products to solve a bad sound problem.

We are a CPA firm, and just moved into a newly built-out office suite. The total suite is 1700 sq. feet with 5 private offices. We have a terrible problem in that we can all clearly hear conversations in adjoining offices. We also have a bad echo in the offices.

Our offices have 14 foot ceilings, and the plenum above the drop down ceilings is another 6 feet. (We are on the first floor of a five story building, and the plenum above us is used to house lots of duct work, etc for the whole building. The return air is vented through the ceiling lights.

The walls are standard metal studs with sheet rock and insulation within. Our sense is that the sound problem is the ceiling. We looked at your Plenum Barrier-Sound absorber, but our contractor is concerned that it will be too difficult to install. The plenum is 6 feet high, and full of duct work, wiring, etc. He says it would be a huge “cut and paste job” and would wind up looking like a patchwork quilt.

We’ve also considered putting the Wall Panels in our offices, hoping that would absorb the sound before it has a chance to enter the plenum.

Any advice would be much appreciated!! I am a CPA and not a contractor, but our contractor really seems stumped.

Thank you,



Thanks for the E-mail. I can tell you that the problem is, in fact, the ceiling so that will be my area of focus. The ceiling treatment won’t help the echo problem in the room but taking care of that it really quite easy so we can deal with that later. It will probably be easiest to discuss this so please feel free to call me if you would like.

I have already talked to two people today about a problem very similar to this and have at least one other E-mail about something similar which means that I am going to draft an entry on my blog about this and publish it so others are able to get this information as well. I do want to put this out there right now- a drop ceiling is about the worst thing to start with when you are trying to block sound. I don’t mean to take the wind out of your sails or discourage you, but I need you to understand that for my own sanity.

Identify The Problem

Before you begin to look for options for blocking the sound, you need to find where the sound is leaking out or leaking out the most. Without doing this, It would be like trying to plug a leaky fish tank without knowing where it was leaking. This can be done quite easily with your ears, and believe it or not, your eyes. I commonly suggest exploring this in two ways. The first would be to wait until the office is as quiet as possible (before or after hours) and get a radio or CD player as a good, constant noise source. Pick a song with lyrics rather than just music and put it areas in adjacent rooms. Go into the room in question and listen. Is it coming through the ducts, the ceiling, the cracks around the door, under the door, through the wall, etc. Trust your ear. The other way is to turn on the lights in every room around the room in question before going into the room and turn the lights off. Look for light. Where you have light leaks, you have sound leaks. IMPORTANT – Keep in mind, light leaks may be above the drop ceiling tiles, so take one of those out before you start.

The Principles Of Soundproofing

Blocking sound is done by keeping three things in mind. (1)Common air space, (2)mass & density, and (3)hard surface contact. These are the three ways that sound travels into or out of a room, and it works in that order. Sound is a lot like water, so visualizing water traveling into or out of a room usually helps people understand this whole idea. The first thing above, common air space, is the FIRST path that sound uses, so this needs to be explored first. Believe it or not, if you have a 5% air gap in any kind of a noise barrier, 90% of the sound leaks through that air space. So, with this in mind, I would like you to explore three areas, the air gaps around the door, the HVAC system, and the common wall (which will lead into the second).

Alternate Soltuions From Acoustical Surfaces

Hopefully, you were able to use the light test to come up with common air gaps. I would start there and fix those before treating EVERYTHING in the room. Chances are that this will not only be the most cost-effective part of the whole process but it may reduce it to an acceptable level. Using my past experience and knowledge, these areas are just about always the air gaps around the door and the ceiling. We have a few different types of DOOR SEAL KITS that can be attached to just about any door and seal up the jamb (sides and top) as well as the door bottom. For the ceiling, you may want to look at the BARRIER-DECOUPLER which is the most cost-effective approach by far but does not have a class A fire rating, our 8lb COMPOSITE ECHO ELIMINATOR which will not block quite as much sound as the barrier-decoupler but it is class A fire rated. Both of these would be put onto the backs of the ceiling tiles that you have now. IMPORTANT – Both of these options will add a lot of weight to the ceiling so you will likely need to add extra supports so that the ceiling does not fall down under the added weight. If you are looking for replacement ceiling tiles, you may want to explore the SOUND BARRIER ACT CEILING TILES which have the mass loaded vinyl backer but are by far, the most expensive approach.

The one thing that makes this situation more difficult than most is the plenum return for the HVAC system. This basically means that there is no way to isolate the common air spaces between the offices which have a major impact on the final result. The only way that I have heard to help is to get an HVAC Contractor to fabricate and install “L” shape boots for above the ceiling tiles so that the sound being pulled from the room is forces to make a right turn. These boots are lined with our QUIET LINER which is a roll of cotton that has an antimicrobial facing on one side. This basically acts like a car muffler forcing the sound to pass by an absorptive surface.

I have not yet talked about the walls which I can leave for future correspondence if needed. I have helped quite a few people in the past do the best that they can with noise issues like this and always suggest treating the doors and the ceiling, and in this case, the plenum return factor and then use the offices for a week and re-assess the problem. The idea here is that you want to plug the biggest leaks first and then step back and see what you’ve done. It may be perfect and you can go about your business and it may need further investigation and treatment. With that said, I always suggest that people call me back if they need additional products or if there is something that didn’t work and I very rarely hear back from people which leads me to believe that the solution worked, or worked well enough to make them happy. In my business, no news is good news.


  1. Noelle Raque

    I live in a townhouse and I can hear the people above me on my 1st floor like they are in here with me. Their kitchen is directly above my&my children’s bed room. I rent so what can I do to reduce the noise. I’ve tried landlord, police, talking with them. We are sleeping on first floor because the noise is so loud. Please help. Sleepless in Louisville.

  2. Ted


    Thank you for the comment and I’m really sorry to hear you’re having problems like this. The difficulty with situations like this is that in order to even START to REDUCE the noise a little bit, you will have to do construction work to the structure. The products that will fix, or start to fix the problem are construction grade products like underlaments that need to go under the finish floor on the unit above – or products that are used to hang/float sheetrock over your ceiling on the first floor. Rental type situations are really difficult because of the fact that the products that will fix/reduce the problem are not cheap / easy fixes and investing that kind of time and money into a property that is not a permanent living situation is not likely. If you would like me to go through a few options with you to look into it further, please let me know. I would be happy to.

  3. Candida

    Hi… im looking for a sound absorbing (?) material to staple into place on my bare ceiling joists in basement. Doesn’t have to be great looking. Don’t care. Just want kids to be able to play down there with limited noise coming thru to first floor. Any input would be greatly appreciated. THANKS! p.s. it should also be somewhat fireproof i guess

    • Ted W

      Hello and thanks for the comment.

      There are a few things to consider when treating a space like this. The first question is whether or not you have HVAC air ducts that connect the downstairs with the upstairs or the rest of the house. If there are air ducts, you are going to want to treat those before closing up the ceiling.

      Regarding a product to use to stop sound, drywall/sheetrock is going to reduce the most sound for the lowest cost. You can always do two layers of sheetrock on the ceiling to reduce even more sound. For what you are doing/looking for in this case, this type of treatment is going to be the most effective for the lowest cost.

      Please let me know if you have any more questions.


  4. Don Sarpe


    What is a good architectural detail for the wall to ceiling intersection in office/medical exam rooms where the walls are drywall (with resilient channel) but the ceilings tee bar with drop in 2X4′ acoustical tile? How higher than the ceilings must the wall assembly go and how does the fiberglass go over tee bars?


    • Ted W

      Hey Don,

      Unfortunately there really isn’t an ideal fix/solution when it comes to rooms that have walls that do not go all the way to the roof deck. A drop-ceiling tile situation is an extremely difficult place to start when you are trying to block/contain sound transmission from room to room. It is, however, a necessary evil when it comes to building design and construction.

      I would suggest extending the wall 6-10″ above the ceiling grid and using a thin, foam-core tape between the drywall and the perimeter angle of the t-bar grid. Some have also used a non-hardening construction sealant on the plenum side of this joint if the thing foam-core tape is not readily available. Install standard office-type ceiling tiles and back each with a piece of either 1/2″ or 5/8″ drywall. Depending on the type of HVAC system, you may pick up a few additional points by installing a layer of an absorptive surface, 1″ Quiet Liner or some type of fiberglass insulation, on the back side of the drywall. This will prevent the sound that does get into the plenum from reflecting from the deck to the drywall and back again.

      The other factors that you might want to consider are the lights and the HVAC system. Many times, the HVAC system is a plenum return and if this is the case it is common to put a 90° section of duct on the back of each return register and line this duct section with an absorptive surface like the Quiet Liner mentioned above. Point these boots away from each other if possible. Depending on the style of lighting, many people have made boxes in the plenum using the Echo Eliminator 8lb Composite. These panels can be used to block sound, but will also reduce the air exchange rate that some lighting systems use to cool themselves.

      I hope you find this information helpful. Please let me know if you have more questions or need any more information.


  5. ernie

    Hello Ted,

    I glad i came across your blog.

    I’m a general contractor and have a client with a conference room that has an exposed poured concrete ceiling, and during conference calls they have an echo problem wile using the conferencing system. The apparatus picks up the echo bouncing from the ceiling and turns off the mic so conversations get difficult. What do you recommend for this? Esthetics are not important at all. I can send you a short video of the ceiling that i will upload to youtube so you wont get a huge file to dl. thanks in advance.


    • Ted W

      If you could send me the dimensions of the space (height, width, depth), a digital picture or two and/or the list of the surfaces in the room (wood floors, concrete walls, concrete ceilings, etc.), and your address I would be happy to send you some product samples of a few potential products that could work. It’s always easier to have them in hand – especially when talking to your customer.

  6. Bob T

    We have adjacent offices with 2×4/drywall walls to about 10′, 8′ suspended ceilings with fluorescent light fixtures. Space above the suspended ceilings is additional 15′, so we have lots of access. Would it be a bad idea to unroll insulation (probably non-itch/non-fiberglass bats on top of existing ceiling tiles? Offices are about 14×16. I am building owner.

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