Super Soundproofing Community Forum

Soundproofing Forum Topics => Soundproofing your Condo, Townhouse or Bed & Breakfast => Topic started by: Bryant Harden on October 13, 2004, 01:01:30 AM

Title: Gypsum board
Post by: Bryant Harden on October 13, 2004, 01:01:30 AM
Hey ....give me some comments on Gypsum board for soundproofing.
Title: Re: Gypsum board
Post by: Kira on April 26, 2005, 12:35:39 AM
If you are refering to drywall, (sheetrock) it will do little or nothing to stop sound transmission. I live in a older mobile home and I took out the interior paneling and reinsulated with r-13 and 5/8" drywall and there was not real noticible improvement in sound blocking.
Title: Re: Gypsum board
Post by: supersoundproofing on May 10, 2005, 12:50:32 AM
You are right.







Contrary to what you would read on U.S. Gypsums website, which gives glowing praise to the soundblocking qualities of Gypsum Board, (Also known as sheetrock and wallboard), It only has a STC (in practice) of about 8-10 STC points.







That makes sense, as a typical wall is 20 STC points.  (2 layers of 5/8" sheetrock (8+8= 16 plus the wall separation= 20).  This is a typical wall which means conversation can be heard through it.







In practice the DB rating of the sound you wish to block is equal to the STC rating you need to reduce it by 50% or more.  SO traffic noise at 60db would need a wall with a 60 STC rating.







Of course, there will be those who argue this is too simple, but it does work well in practice without getting involved in massive math and acoustical measurements, which never seem to work out anyway!







How to get that kind of wall (or ceiling?) see



http://www.soundproofing.org/infopages/channel.htm



STC?  Sound Transmissibility Class
Title: Re: Gypsum board
Post by: John Rice on May 14, 2005, 09:23:13 PM
You guys have really got to get your facts straight. 5/8" drywall has an STC in the low 20's, not great by any means, but not 8.

Also, YOU CAN’T JUST ADD THE STCs of two products on a wall to give you the overall wall STC. Even if the STC of a sheet of drywall was 8 (Which it isn’t), you don't add 8 + 8 to get your STC, it is simply more complicated that that. The best way is to look at tested ratings for a variety of wall and ceiling assemblies, which are available.

If you are going to give advice on this board, you need to hit the books and quit dispensing this uninformed opinions to people who need help solving their problems.
Title: Re: Gypsum board
Post by: supersoundproofing on May 14, 2005, 09:42:49 PM
Thanks John, for YOUR opinion.  Of course there is always more that can be explained and explained and explained again.



While the purists argue about simplified explanations such are ours, it does work in the field and is a good rule of thumb for the uninformed.  



We're not running MIT here, just trying keep things as simple as we can and still get over the basics of sound control so they don't have to hire a consultant to explain it to them, (much like we have to have a lawyer explain the law).



OUR SOUNDPROOFING RULES



Rule one: deal with the sound as close to the source as possible.



Rule Two: put something between the source and the target as close to the source as possible.



Rule Three: more is always better.



Rule Four: soumetimes the lab reports are wrong and the field results are right.



Rule Five: Someone will always be willing to argue about it.





John, you would probably be more at home on the newsgroup for professionals at:

alt.sci.physics.acoustics

(This is not a link- it's the address of the usegroup) newsgroup.    The regulars there are mostly professional and academic and are located in the UK so look down on us common Americans or anyone not willing to spend a fortune on consulting fees to generate a impressive but, mostly useless report,  or who, (God Forbid!),  might happen to try make a buck.

Title: Re: Gypsum board
Post by: John Rice on May 15, 2005, 07:08:33 AM
You don’t have to be a “purist” or scientist to understand the basics of soundproofing. If you are going to dispense advice, it needs to be grounded in fact. The reality is, you can’t just purchase a layer of MLV (from you of course) and “presto”, you get another 26 STC, problem solved!!!! People need to understand that you get diminishing return as you add material, so you need to combine adding mass (MLV, more drywall, whatever..) with proper disconnection (resilient channel or clips), and the use of damping material (viscoelastic) to form an assembly that properly resists sound transmission.

More may always be better, but more is also more expensive. If you do it right, you don’t need to spend thousands on material.

I wouldn’t be so quick to discount detailed work that has been done out there that can help people understand which assemblies work and which don’t. Why not try to learn from others? If someone has run tests, can’t we gain something from that? Maybe the STC won’t be exactly the same in the field, but so what, you still have an idea of what works and what doesn’t.

Try reading “Noise Control Manual for Residential Buildings” by David A. Harris or check out sites like the following:

http://www.cmhc-schl.gc.ca/publications/en/rh-pr/tech/90246.htm

The fact is, your products can play a role in these types of assemblies, but people need read advice grounded in fact. Trying to chalk up simplistic and misguided advice to the fact that you aren’t MIT is lazy . There are simple concepts that need to be understood and don’t require sophisticated knowledge, just the willingness to do a little homework.
Title: Re: Gypsum board
Post by: supersoundproofing on May 23, 2005, 12:08:10 AM
We  DO know what works in the field and know that glowing lab reports are meaningless, having countless customers recount the expensive acousticians report and project plan not working.  



We have been out there and worked with contractors who are very effective in their work, who also discount the "detailed work" and wonderful lab reports and have even talked with U.S. Gypsums techincal experts who admitted privately that their claims are exaggerated and hinge on the demands of their sales department.



Tell me, if gypsum board really has such high ratings, how come you can hear conversation through a wall with it.  How come fiberglass batting doesn't work either?  Gypsum board at .25 a sq ft is certainly much cheaper than real sound control products, why not just use lots of it?  ('Cause it don't work is why).



Don't accuse us that just because we over-simplify that we are  doing a disservice to our cliental, who mostly could give a rodents rear end about the specs, but would just like to understand enough not to be taken for a ride by some numbers spouting "expert" and perhaps be able to do a soundproofing job to a level they expect.
Title: Re: Gypsum board
Post by: John Rice on May 23, 2005, 08:04:37 PM
You need to give facts, plain and simple. Quit stating things that aren't true and I will quit calling you on it. I am not saying that all of your advice is wrong, just that you say some things that aren't true and are misleading. Heck, if you would just stop pretending that STCs are additive it would be a start.

The fact that you don't understand that basic information is very telling about your knowledge.

If you have so many glowing testimonials, let's see some. I don't see an single testimonial on this entire board.  Put up some case studies, real world situations with a description of the problem, photos, specific techniques applied, and some comments from the homeowner.  Isn't that what people really want? They have a problem, what have other people tried and has worked? What are the owners comments about the work? Did it meet their expectations?

Misleading information and a lack of testimonials is a problem for you. You claim it works in the field, so let's have some specifics.
Title: Re: Gypsum board
Post by: John Rice on May 23, 2005, 08:09:24 PM
One more thing, you CAN make a soundproof wall out of Gypsum if you use resilient channel/sound clips and viscoelastic material for dampening.

The main disadvantage is that it is relatively thick compared with MLV.

If you want to learn how to soundproof a wall using Gypsum, check out www.asc-soundproof.com, they can teach you something.
Title: Re: Gypsum board
Post by: supersoundproofing on May 31, 2005, 04:20:15 AM
Of  course,  we can all learn something from anyone-  even those who can teach us what not to do!



Don't you think it's a little audacious to come on a BBS system and plug a competitor?



Makes one wonder about your motives.
Title: Re: Gypsum board
Post by: Vickie on June 07, 2005, 04:33:27 AM
I have found a material called QuietRock soundproof drywall (www.quietsolution.com) that seems to be
very promising and can be mounted directly on top of current/conventional drywall.  It claims to provide better soundproofing than MLV or soundboard
(Hemasote or SoundBarrier) under conventional drywall, and in addition, it cannot be "short-circuited" such as with other techniques because it does not have to
"float."   The site appears to be pretty credible and provides information based on studies performed on the various products (and at least they understand Mass Law).  

If anyone has any comments on this product (John Rice, are you still out there?) I would greatly appreciate it.
Title: Re: Gypsum board
Post by: supersoundproofing on June 12, 2005, 05:53:23 PM
The pros of QuietRock seem to be mostly the efectiveness.

The cons are the massivenessand the cost, weight, which causes handling/shipping problems.

You can obtain the same results with floating walls and ceiling without risk of a hernia.
******************************************

If you are sold on the idea of sandwich visco-elastic wallboard,here's an excerp from the website:

We now have the above green Insulation Tape in the 2' or 4' wide material (yes, that's 2 "Feet" and 4 "Feet" wide!), to cover the underside of an entire subfloor panel.  This will add dampening to the panel, reducing the resonant "boom" when walking on the floor.  All these tapes come with a peel off backing for easy, no-muss application. This also works well for drywall panels, too.  Info about floors.
 

This wide green Insulation tape is also available with peel-off adhesive on both sides! This for quickly adhering drywall panels together with a minimum of fasteners into the studding. (For instance, mating together 1/2" drywall with 3/8" with the tape inside is superior to using one thickness of 5/8" drywall).  It is a replacement for messy liquid "visco-elastic adhesives" that changes the sound characteristics of mated wall paneling.  This double-sided adhesive tape can also be used for quickly mounting thick foam to the wall without a liquid adhesive.  No muss, no fuss.  Mass loaded vinyl is usually too heavy for the tape, but a few staples here and there may be used.
***************************************
This is simpler than hauling in QuietRock and actually when you do the numbers, far cheaper!

BJ
Title: Re: Gypsum board
Post by: John Rice on June 13, 2005, 09:17:39 PM
I do think that QuietRock would be quite effective because it uses mass and viscoelastic properties to reduce sound transfer. They basically roll up some of the ideas on this board into a single product. The 5/8” product looks great since it doesn’t take up more wall/ceiling space than regular drywall.

I must agree that the logistics of shipment and install (it has to be quite heavy and isn’t easy to cut) would need to be worked out before implementing such a solution.  A contractor would probably be a must to do the heavy lifting, cutting, etc..

One thing I am not sure of is how well QuietRock would be at reducing impact sound through a ceiling. You may still need to hang it on sound clips to get a true disconnection, though I am not sure. If you use their entire system with QuietWood on the top and QuietRock below, it wouldn’t be an issue. If you live in a condo and can’t change the floor above you, sound clips may still be necessary.

BTW – If you make your own system with a viscoelastic sandwich, I would use Wall Damp squares between two layers of drywall , but that is just my opinion.

John Rice
Title: Re: Gypsum board
Post by: Simon Ley on June 22, 2005, 02:07:45 PM
Hey John,

I am a contractor, in a band, and just in the final stages of soundproofing a rehearsal room in the basement of my duplex house.

My plan is to fill the wall and ceiling cavities with 'Fill-a-foam' (I was going to use a cellulose 'blown- in' insulation but it would not stick in the ceiling with out first closing the ceiling and I was not comfortable with not being able to see that the entire cavity would be filled) then I will use two layers of 5/8" sheetrock or du-rock (concrete tile backer) then MLV, then resilient channel (no sound-clips) then a single (or double layer, depending on the results) of 5/8" drywall cut a 1/4" short from the ceilings, walls and floor, that joint would then be filled with either a silicone or latex caulk.

Do you think it is absolutely necessary to spend the money on the sound-clips? And do you think sheetrock is as good at blocking sound transmission as concrete-board?

My band is loud and has lots of low-end bass signals, the room is not that big (about 12'x12') do think I'm on the right track?

Thanks you in advance for any of your input.

Simon.
Title: Re: Gypsum board
Post by: William  Nash on June 23, 2005, 01:46:56 AM
You'll find (as many others have) that the "Filler-Foam" will create a hard mass that will conduct sound very well- thereby negating anything else you do.  The dead air space works for you- don't fill it with something that will make it worse!
Title: Re: Gypsum board
Post by: luispa on March 28, 2008, 08:03:59 PM
If you are sold on the idea of sandwich visco-elastic wallboard,here's an excerp from the website:

We now have the above green Insulation Tape in the 2' or 4' wide material (yes, that's 2 "Feet" and 4 "Feet" wide!), to cover the underside of an entire subfloor panel.  This will add dampening to the panel, reducing the resonant "boom" when walking on the floor.  All these tapes come with a peel off backing for easy, no-muss application. This also works well for drywall panels, too.  Info about floors.
 

This wide green Insulation tape is also available with peel-off adhesive on both sides! This for quickly adhering drywall panels together with a minimum of fasteners into the studding. (For instance, mating together 1/2" drywall with 3/8" with the tape inside is superior to using one thickness of 5/8" drywall).  It is a replacement for messy liquid "visco-elastic adhesives" that changes the sound characteristics of mated wall paneling.  This double-sided adhesive tape can also be used for quickly mounting thick foam to the wall without a liquid adhesive.  No muss, no fuss.  Mass loaded vinyl is usually too heavy for the tape, but a few staples here and there may be used.
BJ

Hi,

I'm from Argentina. I'm evaluating alternatives for soundproofing my practice room (I play the saxophone). It seems the visco-elastic is one of the best alternatives. At this time, the best alternative I found is (from the inside to the outside):

Drywall
-------------------------------------------------------------------
visco elastic glue or tape
-------------------------------------------------------------------
Drywall
-------------------------------------------------------------------
Resilient Channel
-------------------------------------------------------------------
Glass wool
-------------------------------------------------------------------
Original wall

It's impossible to get Green Glue or Green Insulation Tape in my country. What replacement alternative could I use? I'm asking for a more common glue. Otherwise, how perform the polyethylene closed-cell foam between two drywall boards as a dampening material?

Thank you very much in advance.
Title: Re: Gypsum board
Post by: Mark Daveis on March 29, 2008, 06:10:16 PM
Use wall damp squares or build a brick wall so that it gives you plenty of mass and its cheap plus you dont have to mess about with any viscous glues.
Other products wont work as it has to be a specially made viscous compound. :)
Title: Re: Gypsum board
Post by: johnbergstromslc on March 29, 2008, 10:25:57 PM
I would even advise to skip the viscoelastic layer altogether.  In your wall assembly, the resilient channel will be doing most of the work in killing the noise and a drywall interlayer won't add much, relative to the money you'd have to spend. 

But use as thick as possible drywall, 5/8" or 16 mm, and don't forget about sealing.  You can build the most elaborate wall setup, but if you skip the sealing you're wasting your time and money. 
Title: Re: Gypsum board
Post by: luispa on March 31, 2008, 02:36:30 PM
Thanks for the replies. The original wall is a 3 inches brick wall. The new wall is supposed to be isolated from the old wall, fixed to door and ceiling using acoustic tape. Does this kind of work justify the use of Green Glue or similar?

Another question: What are the differences between using glass wool and mineral rock wool?

Thank you very much in advance.
Title: Re: Gypsum board
Post by: Mark Daveis on April 01, 2008, 10:49:20 PM
The double wall design wil do most of the soundproofing so using GG will help a bit for LF and resonance problems but you may not need that level of soundproofing unless lots of bass noise.:)
Title: Re: Gypsum board
Post by: joel on May 23, 2008, 03:35:22 PM
There are 4 basic soundproofing elements to keep in mind:
1. Decouple vibrating surfaces from the structurals (isolation tape, resilient channel, sound isolation clips)
2. Absorb and block sound within a contained space (inside wall/ceiling cavity)
3. Barrier remaining airborne sound (MLV)
4.Resonance - damp vibration between multiple layers of dry wall

Quiet rock uses a 15 year old formula "damping" compound that gets hard inside the assembly - I had a can of "Noise Killer" (that is the original name of the patented compound when the smart guys who started Quiet solutions bought the patents, materials, equipment, etc in Arizona and moved it to Silicon Valley) blow it's top last summer (it was real hot in my office) and get all over several sets of plans.  The material is hard in most places and has hardly any flex at all.  Another test sample of Green Glue between "stuff" that is almost 3 years old and more than fully cured is still sticky and flexible to the touch.  How's that for a "field test"
And when you use resilient channel (at least 85% of ALL installations I have either seen with my own eyes or spoken to users over the phone) have been "grounded out" for one reason or the other (installed wrong side up, run into structural at ends, dry wall screwed through to structural begind) - thus rendering it useless and actually increasing sound transmission.  The most common mistake with resilient channel is to use it on top of a layer of dry wall and then attach another sheet of dry wall on top.  For accurate info on this see  http://www.bkl.ca/building-construction/use-of-resilient-channel/
As for resonance - that is where Green Glue is really effective.  See the test results at  http://soundproofing.org/infopages/ggpages.htm