My experience with Green Glue

[Brian R]

hi Eric, everybody,

when we talk cost-effective, we open up a situation that can't be resolved in simple terms.

Rod, for example, thinks that floor space lost should be taken into account when calculating the cost of a wall:

http://www.recording.org/ftopic-20947-15.html

As does at least one commercial company out there... I don't think that is all that great of a consideration, and i've never included it in any cost analysis, and i would hope that audio alloy doesn't include it, either. seems generally unreasonable.


Labor, on the other hand, must be included for approximately 99.9% of constructions. the 0.1% being pure DIY work. But i guess you could turn around and argue that time is money, and if my studio took 2 years to build, i could have made (working at mcdonalds) 50 grand in that time, so add 50 grand to the price tag. or hours*9 bucks or whatever you want to do. get a night job at Mini Mart, etc.



my point is this: any cost analysis ventures away from purely objective analysis, period. there is no limit to how absurd they can be in any direction, either commercial, or anti-commercial.



so i'll leave it up to you folks, we have 3rd party data, including comparisons to same assemblies without Green. there is no same-lab data for the doulbe-stud wall (which is, i think, the best stud wall on record). but, then, I once read a post by one fellow where he stated that 3rd party tests meant nothing, as "If one pays a lab or a study office, they make whatever you like". if someone wishes to be that unreasonable, there will always be opportunity for that.

The last time we were to a 3rd party lab, the majority of the time was spent testing things for specific commercial applications, and only a tiny number of generic tests - just 2x4 walls - were done.

we'll be back to run similar comparisons on at least double stud and RC/RSIC walls, hopefully this summer.


lemme know, could be fun & take care

Brian

i am officially tired of editing this post, take it as it stands

[Brian R]

also, if you like, i will explain in straight-up terms the impact that damping has on any structure, ranging from a single panel to a single studded panel, to a 2x4 all, to a double stud wall, to a staggered stud wall, to an RC wall (i still have question marks about the impact on RC systems, working to fill the knowledge gaps). And, as thus far the 3rd party tests are almost totally in line with what we predicted, so will whatever comments i make in this discussion that i don't have 3rd party data to verify. And i think nobody would suffer from that. :D

[the dreamer]

also, if you like, i will explain in straight-up terms the impact that damping has on any structure, ranging from a single panel to a single studded......

Brian, I think this is very interesting for all of us, so please explain!!!

Thank you.

Florian

[z60611]

the dreamer

Start here
http://www.audioalloy.com/tech_library.htm
(Odds are Brian wrote most of those)

or start here
http://www.avsforum.com/avs-vb/showt...32#post4913932

[the dreamer]

Z, thanks a lot!

[Brian R]

hey Florian, Z, all

if Rod and/or Steve would like discussion of damping and walls on their forum, i'll offer what i can.

and given my druthers, i'd ask that the convo just be about damping, and not GG in particular, if that seems reasonable.

[Rod Gervais]

Rod, for example, thinks that floor space lost should be taken into account when calculating the cost of a wall:

http://www.recording.org/ftopic-20947-15.html

As does at least one commercial company out there... I don't think that is all that great of a consideration, and i've never included it in any cost analysis, and i would hope that audio alloy doesn't include it, either. seems generally unreasonable.

Brian,

1st Please take it in the context that it was written......... and then it is not unreasonable at all.

In new construction - that real estate costs X per square foot - and if a client needs 3,000 s.f. of usable space and then I have to allocate 500 s.f. for treatments - the client pays for the entire 3,500 s.f.

I note in the thread that you link to - in real terms - new construction costs

I also note in there that in the case of existing buildings - if people can spare the space - no problem.

2nd........ you have to include costs incurred as a part of the equation - this unless a product does something new and exciting that no material has ever done before.

But if it's simply a matter of going from "A" to "B" - with exactly the same results (from an isolation point of view) in the end - then cost is everything.

Why would I suggest to a client that they spend additional funds if they can get the same results for less money?

Sincerely,

Rod

[Rod Gervais]

hey Florian, Z, all

if Rod and/or Steve would like discussion of damping and walls on their forum, i'll offer what i can.

and given my druthers, i'd ask that the convo just be about damping, and not GG in particular, if that seems reasonable.

Brian,

That seems very reasonable...........

So what (exactly) are the benefits of damping between drywall layers?

Rod

[Brian R]

Rod, for example, thinks that floor space lost should be taken into account when calculating the cost of a wall:

http://www.recording.org/ftopic-20947-15.html

As does at least one commercial company out there... I don't think that is all that great of a consideration, and i've never included it in any cost analysis, and i would hope that audio alloy doesn't include it, either. seems generally unreasonable.

Brian,

1st Please take it in the context that it was written......... and then it is not unreasonable at all.

In new construction - that real estate costs X per square foot - and if a client needs 3,000 s.f. of usable space and then I have to allocate 500 s.f. for treatments - the client pays for the entire 3,500 s.f.

I note in the thread that you link to - in real terms - new construction costs

I also note in there that in the case of existing buildings - if people can spare the space - no problem.

2nd........ you have to include costs incurred as a part of the equation - this unless a product does something new and exciting that no material has ever done before.

But if it's simply a matter of going from "A" to "B" - with exactly the same results (from an isolation point of view) in the end - then cost is everything.

Why would I suggest to a client that they spend additional funds if they can get the same results for less money?

Sincerely,

Rod

well, fair enough, if you feel it's reasonable to include floor space @ 200 bucks/square foot for new purchase/assemblies, i can see your logic.

would you apply that logic to remodeling as well? lose 2" of floor space, add 200 bucks/square foot for cost? it seems NOT based on your comments about existing constructions, and i would agree.

nice feedback.


pardon me, i don't think i fully understood the latter half of your post, but i don't think there's grounds for conclusion. :)

[Brian R]

Brian,

That seems very reasonable...........

So what (exactly) are the benefits of damping between drywall layers?

Rod

i'll answer that in stages as i have time, but be warned, this is not a simple answer, but rather a different answer for any of the following:

-free non-studded single panel
-studded single panel
-single stud wall
-stagg stud wall
-RC wall
-double stud wall

each of those represents a mechanially different system, and no blanket answer can (or hardly) be applied to them all.

Brian


PS: for now, i should probably begin by explaining what damping actually is. damping is energy dissipation. that's it, that's all. damping any given structure works to eliminate stored energy. that's it, that's all.

stored energy WRT walls would have two basic forms

1. resonance
2. energy in transit



it is very important that if anybody is curious about damping, that they understand the basic facts given above. The following do not represent damping:

1. stiffening
2. odd constructions, such as gluing tie-rods between the leaves of a double leaf wall




and the following are not accurate descriptions of the action of a damping mateiral in ANY structure

1. a viscoelastic material "isolates" vibration (commonly this is used, i saw a post from a maker of damped sheets once that stated that the two sides of the sheet were "totally isolated" from one another)

2. that the damping generates forces that resist motion in the wall (this is true, in a way, but wildly inaccurate in the context given)

3. that damping materials convert sound to heat (again, this IS true, but the context that this gets used in is always inaccurate)

4. that damping materials "absorb" sound. in some roundabout way, again, this is sort of true, but is again very inaccurate with respect to the topic at hand.