John Sayers' Recording Studio Design Forum Archive

I am having a very, very hard time finding any 3 pcf insulation in my area (NE Arkansas, close to Memphis, TN). I have searched the forums and have called every place I can think of in this area looking for thermafiber, fibrex, rockwool, roxul, mineral wool...etc. No one knows what I'm talking about, it's so frustrating. I've also called a few places like Johns-manville, 1-800-getpink, etc. These people don't want to talk to individuals, you know how that is. There is a home depot and a Lowes close to my home, but all they carry is the typical R-11, R-19, R-30 stuff. My main purpose is to block sound from traveling outside (neighbors). Is there any hope for finding this stuff? or is there anything at Lowes or Home depot that will give similiar results? This insulation will be used for walls and the ceiling. Thanks for any help...

On a positive note, I was having trouble finding acoustical caulk also and I found a dealer online, White Cap, that sells 29oz USG Acoustical sealant for $4.44 a piece. I ordered 12 for around $47.00 before shipping. Here is the URL:

http://www.whitecapdirect.com/store/wor ... thod=exact

I found Roxul very friendly on the phone, and they gave me the name of a distriubuter very quickly.

Since you're desperate, you might give these a try
http://www.johnlsayers.com/phpBB2/viewforum.php?f=6
http://www.spi-co.com/servicecenterdirectory.mv
http://www.insulationworld.com/
http://www.lwsupply.com/centerloc/4_0_centerloc.asp

I did a google for "703 Arkansas", and it turns out that 703 is a telephone area code there.

I did find this though
http://www.buildingtradesdir.com/guilds ... ation.html

I know a place you can order it from but PM me for the number because I don't want to post the sales guy's number on a forum.

But...before you buy anything, you say you want to get the 703 to block sound - the 703 (nor any insulation) will block sound - you will not get any soundproofing from insulation. To stop sound you need mass (drywall)

ok, so here's my question, does the insulation do any kind of soundproofing at all? I am going to do the double wall thing with 2 layers of drywall and everything...but is the 703 (or similiar) going to give me any less noise outside than say r-19 pink stuff would? Because, if it will not, I will just get the cheaper pink stuff. I am first and foremost concerned with keeping neighbors from calling the cops That is the reason why I was considering the 703 (or similiar) because I thought that I understood from what I've read here on these forums that the more rigid insulation would "block" sound better. let me know what you think...

thanks for the replies thus far, helpful as always.

Insulation INSIDE a wall works in tandem with the mass on both sides to form a damped mass-air-mass barrier - remove ANY of the components and you worsen the performance. In a double framed wall with double wallboard on the OUTSIDE of each frame, and insulation between, proper insulation can improve the performance of the wall (over just air space) by at least 10 dB at some frequencies, slightly less at others.

The insulation helps dampen vibrations in the wallboard, so should be snugly resting against the panels on either side - unfaced fluffy fiberglass is cheaper than the heavier stuff but helps a few db when placed BETWEEN two layers of heavier fiberglass. However, it's been found that for music, the optimum density of insulation should be between 2 to 3 pounds per cubic foot - lighter density improves bass TL slightly but worsens higher frequency TL; heavier density does the opposite.

http://www.usg.com/Design_Solutions/2_3 ... onperf.asp

By itself, insulation does nothing to block sound. As part of a SYSTEM it's a different story. Still, you need ALL the components of the system or it doesn't work - there's a HUGE difference in isolation between even a fairly heavy, SINGLE mass wall and a properly designed DOUBLE leaf wall... Steve

Ok, Cool, I think I understand. That link was very helpful as well. I have a couple follow up questions...

1. If I use the 703 (or similiar) insulation on one of the leafs, do I need to put insulation on the other leaf as well (i assume i do) and if so, does it need to be the 703 also or can it be the lower density pink stuff? If so, what side does the 703 need to be on, the leaf closest to the music or the leaf closest to outdoors?

2. What is a good way to secure the insulation in the frame so that it stays pressed against the panel?

anyone?

1 - it's better to use 703 or SAFB's on BOTH sides of a wall, partly for damping - however, if it's too expensive you can use regular spun fiberglass on one side - it will probably cost you a couple of STC points using the lighter stuff. It doesn't matter which side gets which insulation, walls have the same attenuation either direction.

2 - The SAFB's are sized so they exert a little bit of pressure against the sides of the studs, so they bow out just a little - this bow puts them in contact with the panel surface. Same with 703 - it's 24" wide, so 24" centers (minus the thickness of one stud) makes them 1-1/2" too wide. For steel studs, no problem - they have nearly zero thickness. For wood studs, you need to trim nearly an inch off each batt before installing.

In a thicker wall, you can fasten a strip of wood or metal stud across the studs horizontally that will keep the insulation against the panels - this needs to be done before the insulation or panels go on... Steve

*Update*

I found a dealer in Memphis that has some 1" 703 in stock, about 384sq ft for $200. Will this work for me, or is the 1" too thin? Would I be better off with this 1" 703 or 6" R-19 pink stuff? Thanks,

blakemcginnis

You can compare 703 and R19 here
http://www.bobgolds.com/AbsorptionCoefficients.htm

In the case of the 1" 703, I assume you'd place them side by side so that they are effectively 3" of 703.

Wow, unless I'm reading those charts incorrectly, the 6.25" pink stuff is more more effective than the 1" 3pcf 703... in fact, it looks as though you don't start seeing an advantage of using the 703 until you get up to about 3" or 4" thickness!! correct me if I'm wrong....


6.25" R19 on wall------0.64 1.14 1.09 0.99 1.00 1.21 1.05

703 1" on wall 3.0 pcf 0.11 0.28 0.68 0.90 0.93 0.96 0.70
703 2" on wall 3.0 pcf 0.17 0.86 1.14 1.07 1.02 0.98 1.00
703 3" on wall 3.0 pcf 0.53 1.19 1.21 1.08 1.01 1.04 1.10
703 4" on wall 3.0 pcf 0.84 1.24 1.24 1.08 1.00 0.97 1.15


Also...what does the document mean when it has figures for " 16" air "

blakemcginnis

In the room (rather than in the wall), insulation spaced out from the wall a little bit is more effective/absorbtive to lower frequencies on a dollar basis than the same thickness of insulation placed right against the wall. It's not as good as if the same distance from the wall were full of insulation, but it's cheaper.

So 16" of air means that behind the insulation there's 16 inches of air before something hard (wall, ceiling).

The 16" statistic is measured because it's a standard depth for acoustical tile hanging ceilings with fluffy insulation on top of them. I believe it is measured without the acoustical tile there.

You're working on insulation in a wall, so this isn't applicable to your situation.

Bob's right - this 16" thing has its own prescribed set of conditions - when you see a test labeled "E405", that means the material was stood off the wall by 405mm, which is 16" - generally, this condition very noticeably improves low frequency performance over normal "Against the wall" measurements... Steve