TM Soundproofing Soundproofing FAQ

Soundproofing FAQ

1) What is the difference between Soundproofing and Acoustics?

Soundproofing is the process where you are trying to contain sound from passing through a membrane i.e. keeping sound from leaving a room or from entering a room. Acoustics is the process where you are trying to control the sound in a room i.e. from echoing off the walls.

2) Is it really possible to create a soundproof barrier?

Definitely. Soundproofing is an art and when done properly with the right materials and applied to the correct places you will be pleasantly surprised at the amazing results.

3) What has changed in the soundproofing industry in the past couple of years?

The construction industry standard for sound control was basically: Insulation, Fiber Board and Resilient Channel. The results are not the greatest to say the least. New products like Damping Compound (Green Glue) Resilient Sound Clips (Whisper Clips) and a better understanding of sound control which includes the use of Acoustical Caulk, Acoustic Pads on electric outlets, Sound Seals on Doors etc. have changed the face of the sound control industry and any contractor/homeowner willing to put in the effort will reap outstanding results.

4) Will stuffing more insulation in my walls/ceilings help me?

Not really. Insulation is but one step in the soundproofing process (an important one that should not be skipped) and adding more of it or more expensive ones (like spray foam, cotton etc.) will not give you that much more. Save your money and move on to the other steps. Read more about Insulation for Soundproofing.

5) What is the best advice you can give me when constructing a new building?

The best thing you can do and this is very important for contractors and architects of hotels and condos is to put down a complete set of 2 sub floors with a damping compound like Green Glue sandwiched in between before the framing of the walls begin. This should be done on each floor. The advantages of doing this are enormous and it will save you a tremendous amount of headache later on when trying to eliminate noise problems associated with flanking noise, recessed lights etc.

Another great thing to do is to build double or at least staggered stud walls in any areas of concern. The benefits of doing these two simple construction techniques will assure you of great results in sound controlling your projects.

6) Why can't I just install materials that have STC ratings of 60 and higher?

If you see materials claiming very high STC numbers, usually they will fall under the category of "if it's too good to be true than it probably is". Look (usually you will have to ask for it) closely at the testing and see what other materials were used in the process. Don't be surprised to see concrete floors or funny spacing of studs etc.

Additionally keep in mind that when a product tests to an STC as a free standing membrane e.g. an STC of 27 does not mean that in a wall/ceiling assembly it will add another 27 STC points it may only add 3 points. Therefore you should always look for testing in wall assemblies similar to the project you are looking to construct.

7) We are building a Hotel or Large Multi-Family project. Can't we just rely on our architect?

Architects are great people and their specialty is designing the project and the construction materials to be used. With the hundreds of components that are involved in every construction project it is impossible to expect an architect to be an expert in every aspect of the project. Instead they have to rely heavily on suppliers and sellers to support their claims through verified tested paperwork allowing the responsibility to be shifted onto the supplier.

If you have done some research on the subject of soundproofing you are sure to have seen just how complicated and confusing it can be. We will just give you one example of a company that was rehabbing a luxury 5 star hotel in South Carolina due to sound control issues. They were convinced to use a very expensive highly touted material with claims of high STC ratings. With half the project under way they realized that the actual on field performance was actually not that great. That is when Trademark Soundproofing received the call from some very harried customers trying to see what went wrong and what they can do for the 2nd half of the project. Our suggestion and materials were less expensive with far better results.

It is imperative for each Hotel/Condo/Multi-family builder/owner to rely on their own research and present that to the architect in order to achieve great results on their sound control and at the same time will probably save themselves a nice amount of money.

8) How about Spray Foam Insulation. I heard that is a great soundproofing product?

Save your money and use cheap (about 3-4 times cheaper) fiberglass or cellulose insulation. Use the extra money on an extra layer of drywall and quality damping compound/Resilient Sound Clips.

Insulation absorbs some sound waves and that's it. The fiberglass will absorb as much if not more than the spray foam. If you carefully read the tests you will see that all insualtions across the board add about 3-4 STC points. This has been confirmed to us by many builders.

In the real field spray foam may actually exacebrate your sound issues. The reason being, you want to keep the building materials as seperated from each other as possible, think "decoupling", Spray foam acts like an extremely powerful adheisive, pulling all the membranes i.e. joists and sheathing, together allowing for easier sound transfer.

(As a side note one thing we do hear from contractors and we have noticed it as well during sound control installs that we have done is that contrary to "science soundproofing" mineral wool and cellulose are better at controlling sound than fiberglass. Either way if you are on a budget fiberglass will do the job).

9) How about the brown fiber board? Every one uses that as "Soundboard"!

The only place fiber board has any use by professional soundproofing companies is on the floor. You read that right, sandwich some fiberboard and Green Glue between 2 layers of sub flooring and you will have a great floor for absorbing impact sound. In walls and ceilings it just does not make the cut. We need "Mass" and drywall is heavier than fiber board. We need absorption, fiberglass can absorb, fiber board is not absorptive enough. When applying a damping compound like Green Glue you need 2 smooth rigid membranes, fiber board is not as smooth as dry wall. Bottom line: use more drywall if you are looking to beef up your walls or ceilings.

10) You got me thinking; now how do I know what really works and which materials are suitable for my project?

Trademark Soundproofing was analyzing and applying all types of soundproofing materials for 2 years before we opened up Additionally we are constantly getting feedback from our growing base of builders and General Contractors. If you read through our articles and browse our carefully selected materials you will notice that what we write makes sense and we are not trying to sell just anything that goes, our reputation depends on it. Additionally browse the internet and you will slowly get the picture of the right way to soundproof, then come back here and see how we prepared it all for you. And remember always feel free to pick up a phone and give us a call at 845-388-1200.

11) What is all the hype about Green Glue?

Green Glue is a visco-elastic damping compound which when applied between 2 rigid membranes e.g. 2 layers of drywall will dissipate (destroy) sound waves that hit the panel thus preventing them from traveling through and/or along the membrane.
Green Glue is the most thoroughly tested and used damping compound on the market and it so versatile that it can be used on floors, walls and ceilings.
Our own field installation and customer feedback has proven time and again that Green Glue lives up to its name by providing outstanding sound isolation results. Read more about Green Glue Damping Compound here.

12) How does an STC reduction compare to a DB reduction?

STC scores are loosely equivalent to db reduction. The difference is that an STC score is determined by comparing actual transmission loss by frequency to a set curve for each STC to determine the score. A db drop would depend on the type of noise needing to be blocked and how much noise the wall/door could stop at the frequencies of that noise.

Customers Questions and Answers

1) Dominic: In my current home I want to add sound control to certain areas. For example the second floor bathroom can be heard in the dining area. How can i add sound control without a major rennovation?

Trademark Soundproofing Reply:

Hi Dominic. At a minimum you would have to blow insulation in the ceiling and add a 2nd layer of drywall. If that is a consideration than please see more details on our soundproofing existing ceilings article.

2) Mark A. : Is your green glue safe for automotive use? I'm thinking about adapting your technology using Mass Loaded Vinyl, green glue (in between) MLV and Neoprene CCF as a top sheet for my classic Jeep. I realize road noise will always be there from the sides and the top, but the recent addition of a performance V8 engine, dual exhaust , and performance mufflers (right under back seat) are causing so much noise it sounds like i'm in a sheet metal race car. I'm looking to eliminate exhaust noise, but retain the performance exhaust I have. Classic jeeps have no insulation and my wife will not ride in my 72 CJ 5 unless I quiet it down. Looking to see if it makes sense purchasing your technology. The car companies like Dynamat, don't have great reputations and the other roll on liquid products just wont cut it. I need something from the pros who know how to sound proof. Thanks for your time. Feel free to call me if it's more convenient for you. Thanks -Mark

Trademark Soundproofing Reply: Hi Mark, It would work but since Green Glue is designed to work at room temperature it will lose performance as temperature rises or lowers. Many of our customers use our MLV for this application with good results. Thank You,

3) Rick L: What would be the best product for sound damping plumbing drain pipes in new construction where the pipes are still exposed? I know some people use cast iron drops and abs for the balance of the drains but not everyone thinks or can afford the cast iron. Do you recommend wrapping the pipes with MLV or do you have another product?

Trademark Soundproofing Reply:

Hi Rick, MLV and insulation around the pipe and then double drywall with green Glue on the wall/ceiling that pie is in. We also have an MLV bonded to fiberglass for pipes. See our Soundproofing Pipe Wrap here.

4) Natalie: Hi there, We just did a remodel and the contractor used spray foam in the wall separating 2 bedrooms. We now hear everything between those 2 bedrooms! What is the best way to soundproof that wall without removing the existing (new) drywall? Will green glue and a new layer of drywall be enough? Please let me know. Thanks!

Trademark Soundproofing Reply:

Hi Natalie, Yes unfortunately we "hear" that many times from clients and have experienced it first hand as well. Spray Foam is not recommended by us for sound control. Adding a 2nd layer of drywall with Green Glue to your wall should help a lot. If you have an open air space (attic) above the 2 rooms then you need to treat the ceiling as well.

5) Sara: Hi there, We are experiencing increased train traffic including horns in the middle of the night. We are about 5 car lengths from the tracks and have a new (2012) constructed manufactured home. We're looking to soundproof inside the walls that face the track and do something with the windows. Any suggestions?

Trademark Soundproofing Reply:

Hi Sara, Adding a 2nd layer of drywall with Green Glue Damping Compound in between is the right way to go for the walls and ceiling. A window sound control panel while a little clumsy, work very well for windows.

You can read a more detailed article here

6) Graham: Question: I am looking at the following ceiling assembly for a floor that is already installed: Joist tape 1/2\" gyp with all edges sound sealed green glue 5/8\" gyp with all edges sound sealed Is the joist tape a reasonable alternative to clips?

Trademark Soundproofing Reply:

Hi Graham, Joist Gasket Tape is not a reasonable alternative to clips and channels which can add an huge 15 STC points to your assembly. The main point of decoupling is to make sure the drywall is not directly secured to the joists which is not done when using the tape. If you are on a budget you can consider using our Value Clips.

7) Donya d: downstairs neighbor complaining of noise my floors are all tile considering wall to wall carpet , can this be done on top of the existing tile? what other soundproof products should I use ? thank you

Trademark Soundproofing Reply:

Hi Donya, You should speak to a carpet installer in regards to installing it over your tile. If you will be doing that, we would recommend that you use the Premium Carpet Underlayment. Thank You

8) Tyler W: I recently built a wood working shop inside half of a 900 sq ft. tin sided shed. I have a non-oiled (ie. loud) air compressor in the shed but outside the shop. I would like to build a cabinet around the compressor to reduce the noise. I have thought about using 2x2s as a frame, and encasing it with 1/4"-1/2" plywood. Is there anything else I can do to reduce the sound?

Trademark Soundproofing Reply:

Hi Tyler. Yes, use 2 layers os 1/2" plywood and sandwich the Green Glue Damping Compound between the 2 layers. You can also add fiberglass panels between the frame to absorb some of the sound. Thank You

9) Paul F: we are putting insulation in our basement ceiling to dampen the sound. I am getting conflicting advice about whether it is better to go with R30 batts in an 8 inch cavity or to go with blown-in fiberglass. Also which is better for filling tight spaces-batt or blown-in?

Trademark Soundproofing Reply: Hi Paul. Our advice is. Don't knock yourself when it comes to insulation. Use whichever is simpler and cheaper, usually fiberglass batts. Nearly all the insulation will perform adequately in absorbing the sound waves. Concentrate more on the decoupling, damping and proper sealing.

10) Aaron: I have an 1890s victorian multi-family home with hardwood floors upstairs, covered with a pet-safe carpet pad and pile carpet. Downstairs, the footsteps have been aided by the carpet, but if the dog plays, or someone drops something, etc., there is thumping downstairs that wakes up the downstairs tenants. I am going to try a large wool area rug in the living room upstairs, where the dog is frequently, but am considering solutions for the ceiling below. I don't want to rip out the original plaster and lathe ceilings, so was considering adding green glue and a layer of drywall, but then came across isomax clips and resilient channel. What would you recommend? Is the glue and drywall adequate to stop impact sounds from above, or do I need some kind of decoupling clips?? Any advice appreciated. I have a couple 200 sq foot rooms where noise is an issue, and cost is a factor here as well. Thanks, Aaron

Trademark Soundproofing Reply:

Hi Aaron. If footstep and impact sound is your main concern than using Resilient Sound Clips and Channels are the way to go. Thank You

11) Tom: I am a developer with a new multi story, high-end condo building going up. I bought the air rights above the conference room - banquet room wing of a new hotel. I am concerned about events in the banquet facility, receptions, parties, etc. with live music transmitting below our first floor. There's a ceiling in the banquet area that is part dry wall, part acoustic tile. There's a space of apprx 10' between their ceiling and the first floor of the condos. The condo floor is a poured in place, 8" concrete slab. Already, most of the plumbing drain lines for the condo are in and the grid system for the ceiling below. There is not enough room to install a suspended gypboard ceiling between the banquet room ceiling and the condo floor. How can I minimize or isolate the low frequency sound transfer from the banquet room to the condo? Thank you

Trademark Soundproofing Reply:

Hi Tom, On the areas where you have drywall you can install a 2nd layer of drywall with the Green Glue Damping Compound in between. On the areas that have acoustic tiles you would be best off replacing that with a drywall ceiling and using the GG as well. If that is not an option you can use our Ceiling Tile Barriers which we have received very positive feedback on. Also be sure to install standard fiberglass insulation in the entire ceiling. Thank You

12) Devora C: My toy hauler garage is noisy- I hear everything outside - even people talking. Adding a drywall layer with green glue seems good choice, but is it hypoallergenic (I cannot handle toxins); what drywall is lightweight b/c I cannot add any more weight to my trailer. My garage is 8X10.

Trademark Soundproofing Reply:

Hi Devora, The Green Glue has no toxins you can see the MSDS sheet here

13) Devora C: Thanks for this reply. I want to apply carpet pad and the green glue onto existing walls in my toyhauler garage, but understand that the green glue does not function as an adhesive for the carpet pad. What's the best way to secure both on these RV walls?

Trademark Soundproofing Reply: Hi Devora, The Green Glue should only be used if you can apply it between 2 rigid membranes with each being at least 1/2" thick. We do not have any advise on how to attache carpet to a wall. Thanks.

14) John L: I am converting an upstairs walk in closet to a music practice room. I don't care what the walls look like. To keep sound from going through them and disturbing others, am I better off covering the walls with 2" convoluted foam or adding a layer of drywall with green glue? The room is 6'x8'.

Trademark Soundproofing Reply: Hi John, The extra drywall and Green Glue will keep the sound from going through. The foam is meant for controlling the sound in the closet.

15) Douglas R: We are designing a sports bar. Overhead there is a steel deck and concrete slab and apartments above that. What is the most cost effective material to spray on the underside of the steel deck to reduce sound transmission. Since this will be the finished material, can we do something that is dark charcoal grey...or does the insulation then require a coat of spray paint...does this extra coat of paint create a problem with adherence of the original sprayed on insulation. I guess ideally a tight cell cellulose spray that is already dark charcoal grey in color as a one coat operation. Is there such a product on the market ? And of course estimated cost per sq/ft. Thank You

Trademark Soundproofing Reply: Hi Douglas, I don't know of any spayed insulation that can be left as the finished material other than spray foam. Open cell spray foam will be a lot better for sound absorption than closed cell, although neither of them would be something that we would recommend for sound control. The paint may inhibit the sound absorption you would have to check with the spray foam manufacturer. Thanks.

16) Don P: I live on a very noisy street - lots of traffic noise, and a lot of sound reflected back from taller residences across the street. I am considering putting your 2 lb product between fence slats on an 8' privacy fence 1) Do you recommend this product for this application, and why or why not? 2) This application would essentially involve stacking two 4' wide sheets (one on top, one on bottom) - Should the two sheets be joined in any fashion, and if so, how? 3) How long can I expect your product to last in this application (and is there a problem with it being exposed to the elements)? 4) What type of noise reduction can I expect? Thanks for your help - the noise is driving us nuts!

Trademark Soundproofing Reply: Hi Don, That is a product that is used by many of our customers on outdoor fences. Obviously due to the fence having an open air space above it sound can still go over the fence. You can just overlap the top sheet onto the bottom sheet by an inch. There is no problem using this MLV outdoors. The only issue may be with the material tearing at the points of the fasteners.

17) Conor G: Hi, we are trying to figure out the best solution for soundproofing our upstairs bedrooms from road noise. There is a lot of conflicting information on the web. We were thinking of spray foam insulation in existing walls then replacing the drywall with QuietRock drywall. Is this viable - your website seems to say insulation is not helpful? Any help most appreciated thank you in advance. Conor

Trademark Soundproofing Reply:

Hi Conor, Insulation is an important part of soundproofing. We do not suggest SPRAY foam as fiberglass insulation is better for soundproofing in our experience. It is a very good idea to replace your drywall with a damped drywall . Even better if you create it yourself using 2 layers of half inch drywall with the high quality green glue damping compound in between.

18) Doug L: I am building a home theater in my unfinished basement and want to keep sound from going up to the leaving room and kitchen area above as well as hearing people walk upstairs or air traveling through duct work to the upstairs. I was going to use Roxul insulation with the RC1 resilient channel and 5/8" sheet rock. Would that be enough or should I use the hat channels resilient clips? I am not wanting to had another layer of sheet rock because of the weight and I think this would sufficient.

Trademark Soundproofing Reply:

Hi Doug, If clips and channels are an option we would highly recommend those over standard RC1 resilient channels. It is a worthwhile upgrade.

19) William C: We are finishing off a room in our basement. If I place Roxul soundproof and fire proof 3 inch thick material in between the beams of the ceiling, can the material be spray painted black, as the contractor wants to do instead of placing sheetrock or a drop ceiling? Or is there a better material to use? Thank You Very Much!!!

Trademark Soundproofing Reply: You would have to ask the Roxul company about the painting of their material. As far as soundproofing is concerned you definitely want to add drywall to the ceiling.

20) Hank: I am building a 200 sq. ft workshop with T1-11 paneling and galvalume roof. I have a band saw, miter saw and midi-lathe as my biggest noise makers. My goal is too make sure my neighbors do not have the noise going into their house. They are really great neighbors and want to keep it that way. Any suggestions you have are greatly appreciated. Hank

Trademark Soundproofing Reply:

Hi Hank. For proper soundproofing you would need to build some sort of wall/ceiling frame that you can install insulation into. Then cover with 1/2" plywood or OSB. Put the Green Glue damping compound onto the back of your paneling (provided it is close to 1/2" thick as well) and screw pack to the plywood.

21) Chet O: Hi...I'm building an enclosure for my Onan 35EK generator. I live in a residential area and want this thing to be as quiet as possible. I've tackled the exhaust noise through improved muffling. It's a steel enclosure, so can your products be used and how would you mount them?

Trademark Soundproofing Reply:

Hi Chet. Please see our soundproofing curtain line which I believe should work very well for your application

22) Terri : We are using resilient channels on a ceiling insulated with open cell spray foam because it is under an outside deck. Q: is it ok for the spray foam to be in contact with the channels or should we clear it so no foam is touching the metal? Side Q: We are using Quietrock drywall on an west wall that gets lots of wind, rain, sun, traffic. Which insulation would give best STC: open cell spray foam or fiberglass? Thank you/T

Trademark Soundproofing Reply: Hi Terri, The foam touching the channel will not make much of a difference if it is an open cell foam, still better off just clearing it away. Fiberglass is a better option for sound control than spray foam.

23) Kyle: Can mass loaded vinyl be used on an attic floor? I've been having issues with sound transmission in a master bedroom. I first added a layer of 5/8" drywall and green glue to all the walls, but not the ceiling. Additionally, I put in 3/8" acrylic window inserts. This helped quite a bit, however, it now sounds like the sound is coming through the ceiling. Sticking my head into the attic, it is fairly loud. (Traffic and aircraft noise) I do not want to put a second layer of dry wall up on the ceiling, so I was thinking of laying MLV across the attic floor above the bedroom. Currently the attic has about 12" of cellulose insulation above the bedroom ceiling, and is naturally vented. This is in a northern climate, so I am worried about condensation and moisture issues if I do this.

Trademark Soundproofing Reply: You can try that. Make sure the MLV is snug all around the ends with no place for sound to leak in at the edges. Speak to your insulation contracter regarding the moisture as this is some sort of a vapor barrier.

24) Mike S: I live in an Epcon condo where I share a wall with my neighbor. I don't hear voices, but every time my neighbor closes a kitchen cupboard door. I hear it. It is a common problem with other neighbors I have talked to. Is there a foam that could be sprayed in the walls or something You could recommend? Thanks, Mike

Trademark Soundproofing Reply: You are getting a direct vibration. The proper way to treat it would be to decouple your wall. That is probably a lot of work to do in an existing home for just that type of sound issue.

25) mike: I own a first floor condo was converted apts in florida,exterior is wood,I can hear footsteps from upstairs,the condo is 1000sq ft,what is the best way to sound proof at a reasonable cost,I am selling the unit.its the ceiling that is my biggest concern

Trademark Soundproofing Reply:

Hi Mike. Please see this article on soundproofing existing ceilings.

26) Doug J: Hello. I have one chance to get this right and I am sparing no expense. I have not seen a lot of info on this, but I am planning on using quietrock 510 (its all they sell at my local Lowes) and a layer of green glue in between over the existing drywall. Overkill is not an issue. Is there any reason this is NOT recommended? Again, cost is not a factor. I would use 3 layers of drywall if I had enough space. Thanks

Trademark Soundproofing Reply: Hi Doug, Green Glue can and is used between regular and pre-damped drywall, no issues there. If you want to do it

27) Jenn: Hi ? Your site is super helpful. Thank you. I rent a room in a house built in the 1950s. It is made private by a closed solid wood door. I need a non permanent sound proofing solution, mainly for talking noise, low frequency sounds. Would green glue be permanent and/or destructive to the door surface? I thought about adhering an 8' x 4' cellulose board to the door. Can you please suggest a best solution? Also, should I leave airspace between the door and my sound proofing material, or adhere them flush? Thank you so much!

Trademark Soundproofing Reply:

Hi Jenn. Green Glue will be permanent and cannot be removed. Try our soundproof door panel which uses Velcro around the perimeter.

28) Jennifer: Hi and thank you for getting back to me. Your product looks terrific. Unfortunately, it is a lot more than I can spend. The door does not need to open. Do you sell the material by the yard? I could remove the door handle, plug its hole, and adhere the material to an area the circumscribes the door. Just a thought! Thanks, jenn

Trademark Soundproofing Reply: The smallest would be a 54" by 96" long which is about one hundred dollars less and you would have a very hard time cutting it to fit the door etc.

29) helen: hi, i have a 400 sqft apartment, and I have problems with the footstep, dropping objects, etc. impact noise from upstairs. I dont want to decouple the ceiling. currently, the ceiling drywall ceiling. Do you think spray foam the cellulose will work or help a little bit? or if you have other way you recommend? thanks

Trademark Soundproofing Reply: If there is no insulation there than Cellulose will help a bit, not a a lot.

30) Whitney: Great site. Do you have any advice on finding someone to hire to do the soundproofing? I'm not sure what kind of business is best to go to with my project - drywall, remodeling, general contractors, etc. I'd like to use sound clips and green glue, but I'm not sure who's familiar with those products, and I am wary of spending money on someone who doesn't know exactly what they are doing. I keep reading horror stories of people hiring contractors who end up doing things incorrectly and the person spent all their money and still has a noise issue.

Trademark Soundproofing Reply: That is a legitimate concern. Usually you would want a highly competent drywall contractor who has experience with these materials. We are also happy to guide you/them along. You can also email us your zip code and we can check our database of soundproofing contractors to see if there is anyone in your area.

31) cecile: I am building a 2 family home and contractor gives me the following choices: what is the best option for soundproofing between basement ceiling and first floor- separate apartments? 1. Thermafiber 3''with R-19 2. R-30 3. green glue + 2 layers 5/8 with channel and includes extra 1/4 inch sheetrock 4. Sheetrock/Sound Basement Soundboard and 2 layers 5/8 with channel

Trademark Soundproofing Reply: R-30, Resilient Sound Clips, Hat Channel, 2 layers of sheetrock with Green Glue.

32) John: Thanks for all the good information on your site. I am planning to finish our basement and wanted to soundproof the basement ceiling as much as possible while preserving headroom. Currently, we have wood floors on the first floor and the basement ceiling is exposed floorboards over 2x10 floor joists.I wanted to know if I would achieve a good result by placing one or two layers 3/4 inch drywall between the joists using green glue. This would leave my joists exposed and give me room to add lighting in the ceiling without limiting head clearance. If I did this, would I screw the drywall in or only use green glue because screws would transmit sound? I also have forced air heat and wanted to know your recommendations for limiting sound transfer through my ducts?

Trademark Soundproofing Reply: Your welcome. Green Glue cannot be used as an adhesive and you would have to screw it in

33) Tom P: I am building an enclosure around a noisy outdoor heat pump using plywood with 1 lb. MLV attached to the interior walls. What is the best method of attaching the MLV to plywood? Will liquid nails stick to the MLV or should I use screws?

Trademark Soundproofing Reply: Use screws or roofing nails.

34) Bob: I have a work shop with a ribbed metal ceiling installed that produces a lot of echo or ringing. It has 20" of blown in fiberglass insulation on top of it. Is there anything I can do on the bottom side to dampen the echo or ringing like spray foam or undercoating?

Trademark Soundproofing Reply:

Hi Bob. You can apply the Vibration damping foil tape directly to the metal.

35) james: I am building a new shop (framing is completed) that is split into two sections: one for the shop, and another as an office or guest room. I want to isolate the shop noise from the other space. The primary noise will come from metal working (specifically hammering sheet metal). I'm thinking of just treating the wall between the two spaces (likely two layers of drywall and green glue). Will this be sufficient, or do I need to treat the exterior walls as well?

Trademark Soundproofing Reply: Treating the interior wall should be sufficient (although you may want to give it a better treatment as in decoupling the wall too) provided that the wall goes completely from floor to roof with no air gap above the wall.

36) Mike: I have a ceiling with 2x12 joists. I'm going to do hat channels, etc for the drywall, but I have a lot of space in that joist space to do something with. What do you think about having 4" of fiberglass right up against the plywood of the floor above, and then a second layer of 4" fiberglass at the bottom. To have a bit of an air gap. Or is it just the same as doing one 8", which would be easier. And I know that you don't like spray foam, but in this case if I am willing, and money isn't an object, how about 2" or so of open cell foam onto the plywood to help seal any holes up, and then air gap, and then fiberglass. Thanks, Mike

Trademark Soundproofing Reply:

The 8 inch will work just as well. Better to seal the holes and gaps with an acoustical caulk. We stay away from the spray foam as it "pulls" together the joist and floor which allows for easier transfer of sound.

37) heath s: we are in the middle of a small commercial project where we would like to soundproof the walls as much as is reasonable. We have 3-1/2" metal studs and intend on using quiet rock. What would have the most impact on sound transmission through the walls, the use of mass loaded vinyl attached to the metal studs before the insulation is installed or the installation of fiberglass or mineral wool insulation in the wall cavities. We have eliminated the use of the quiet clips because the floor space that we would lose as a result of their projection into the room was not taken into consideration when the architectural plan was being made and we already have the walls in place.

Trademark Soundproofing Reply: You need to start with insulation in the walls. That is a must however it is not enough. A layer of Mass Loaded Vinyl over that on the studs is a good idea.