Saw this quote on AVS forums about QuietRock

"A single layer of QuietRock 525 on single studs performs similarly to a double-stud wall (actually, a few points less, but less hassle and much less floor space)."

Personaly i have a hard time believing that, it just goes against the law of physics, let's see what Rod has to say about it....

Maybe it does at 2kHz and beyond.... No chance that it can behave anywhere near a double stud wall (with double drywall and insulation) at low frequencies though. Air gap is the dominant player in the TL of a partition... Cheers, Kris

Test data comparing these two wall types: double stud wall; 24 OC with R13 (test# 93-281) http://irc.nrc-cnrc.gc.ca/pubs/fulltext/ir761/ir761.pdf STC 59 50 Hz - 15.6 (db) 63 Hz - 21 80 Hz - 25.5 100 Hz - 28.4 125 Hz - 35 single stud wall QuietRock 525 each side; 24 OC with R13 http://www.quietsolution.com/QR525_both ... _STC55.pdf STC 55 50 Hz - 16 (db) 63 Hz - 16 80 Hz - 21 100 Hz - 24 125 Hz - 37 Hmm. Close. But what's the price difference? 2 sheets of drywall + R13 + 2x4 studs vs. 2 sheets QuietRock + R13 + 2x4 studs Anyone have a calculator handy?

cjbdrm wrote:

Test data comparing these two wall types: double stud wall; 24 OC with R13 (test# 93-281) http://irc.nrc-cnrc.gc.ca/pubs/fulltext/ir761/ir761.pdf STC 59 50 Hz - 15.6 (db) 63 Hz - 21 80 Hz - 25.5 100 Hz - 28.4 125 Hz - 35 single stud wall utilizing QuietRock 525; 24 OC with R13 http://www.quietsolution.com/QR525_both ... _STC55.pdf STC 55 50 Hz - 16 (db) 63 Hz - 16 80 Hz - 21 100 Hz - 24 125 Hz - 37 Hmm. Close. But what's the price difference? 2 sheets of drywall + R13 + 2x4 studs vs. QuietRock + R13 + 2x4 studs Anyone have a calculator handy?

Those are so very much the wrong tests to look at. Try these on for size.......... The claim was that a wall one sided with quietrock would perform similar to a double stud wall. So to begin with - you have to look @ the test results for a wood frame wall with a single sided quietrock application........ and you'll see that in a minute with it's data below it..... Then - in order to do this intelligently - you look for what in standard construction would be similar to it - and from there it's easy to spot the B**l S**t becasue we all know how that would compare with a double framed - or even a staggered stud - wall. So (without further ado) here is the real deal: Test @ Riverbank Labs............... Test @ National Research Quiet Solutions, Test #............... Council Canada – Test ID# TL07-019 w/ Quietrock............... TL-93-098 w/ 5/8” Type X 525, W.S. wall (2x4) @24” oc,..... Gyp., W.S. wall (2x4) @ R13 FG Insulation, 5/8”...............24” oc, R13 FG Insulation, RC-1 Type X Gyp. – STC – 51............. @ 24" o.c. - 5/8” Type X Gyp. – STC 50 Frequency TL............Frequency TL (Hz)..........(dB)..........(Hz) (dB) 50.............17............50.............18.8 63.............18............63.............12.7 80.............18............80.............16.1 100...........17............ 100...........17.2 125...........31............ 125...........25.7 160...........37............ 160...........30.7 200...........37............ 200...........37.4 250...........41............ 250...........44.9 315...........46............ 315...........49.4 400...........46............ 400...........52.7 500...........50............ 500...........56.6 630...........51............ 630...........58.9 6300.........59............ 6300.........64.5 OK - so there you have it - take the same frame - the same insulation and the same 1st layer of drywall - and what you're really comparing is a layer of quiet rock versus resilient channel 24" oc and a 2nd piece of drywall. SORRY - from a cost point of view - you can't beat conventional construction - the STC values are within a point of one another - and they are fairly average across the board...... and please don't say: "Well look how much better they were at 63Hz.... cause I will respond "Sure but look how they lost by @ 400Hz" Besides which I could take that single frame wall - and beat the hell out of the quietrock TL numbers (by far) just by adding one moire layer of 5/8" drywall - and still be cheaper than their wall costs....... Forget it folks - someone is lying out there........ please give me a link to the thread............ Sincerely, Rod

Test 281 is only single drywall on each face...not a very good construction IMO considering the amount a space used. test 93-272 is more representative...double drywall, seperate studs. 50 Hz 23.7 63 Hz 27.8 80 Hz 32.9 100 Hz 38.0 125 Hz 42.4 160 Hz 49.2 200 Hz 54.4 250 Hz 60.8 315 Hz 65.8 400 Hz 70.1 500 Hz 72.7 630 Hz 75.4 800 Hz 77.9 1000 Hz 81.4 1250 Hz 83.8 1600 Hz 86.4 2000 Hz 86.0 2500 Hz 79.4 3150 Hz 79.8 Almost an 8dB improvement in the low end...sizeable if you ask me. Add a few more dB on there if you use green-glue as a constrained layer damper in between the drywall. Cheers Kris

The claim was that a wall one sided with quietrock would perform similar to a double stud wall.

Rod, I took his post to mean 1 layer of QuietRock on each side of the 2x4 wall. http://www.avsforum.com/avs-vb/archive/ ... 12425.html Poster: Kevin Surace Time: 12-17-05, 01:05 PM BTW- I'm not arguing for or against anyone or anything- just trying to educate myself...and happened upon this older thread...thought it was a little far fetched myself which is why I wanted to bring it up for discussion...

I skimmed the thread and was actually impressed by the QuietRock guy...not enough to pay the big $ for their product, but they do seem to have a decent product, tested by reputable labs, and seem to have a good understanding of who the market for that product is. Thanks for the link Cheers, Kris

drfrankencopter wrote:

I skimmed the thread and was actually impressed by the QuietRock guy...not enough to pay the big $ for their product, but they do seem to have a decent product, tested by reputable labs, and seem to have a good understanding of who the market for that product is. Thanks for the link Cheers, Kris

Kris, LOL- well then perhaps you could fill me in on who their clients are........ I've done well over a billion dollars in construction - last project was 3/4 billion - and I have never even considered using their product - I work with architects and engineers who have offices all over the world - who have never considered specifying their product....... I have friends and business aquaintences - whose firms are similar to the ones I work for - and they have never even considered their products........ So they must be targeting the small architects who sometimes like to think that they can spec anything - just because they're preppy........ those guys don't last too long with me............... BTW - just for the record - I do believe that their product does exactly what they say it does - I just have never been able to justify the cost versus standard materials and construction techniques......... and I've been around this for quiet a while - and have no problem using the lastest and greatest products as long as they save me money in the end and deliever an equivilent or better product for my client. Sincerely, Rod

cjbdrm wrote:

The claim was that a wall one sided with quietrock would perform similar to a double stud wall.

Rod, I took his post to mean 1 layer of QuietRock on each side of the 2x4 wall. http://www.avsforum.com/avs-vb/archive/ ... 12425.html Poster: Kevin Surace Time: 12-17-05, 01:05 PM BTW- I'm not arguing for or against anyone or anything- just trying to educate myself...and happened upon this older thread...thought it was a little far fetched myself which is why I wanted to bring it up for discussion...

cj, nope - read his post - he specifically refers to an STC rating of 51 for their product - Here: 2. A standard 5/8" gypsum wall with insulation is an STC 34. With QuietRock 525, it is an STC 51. These are independant lab tested numbers (NRC). The STC 51 wall is the one I refered to seeing as he's the one quoting that number..... their product is single sided in that test..... that's how they describe it. He's comparing that to an STC 54 double wall assembly - BUT - as I showed you - you don't need to build a double frame to match their numbers.......... single frame with rc-1 does that quite well. Sincerely, Rod

A very timely post to find... My brother and I are going to coordinate the work on our basement for a studio space with isolation. He's socking away spare sheets of drywall for me on the jobs he does. I've shown him Rod's book and some of the principles in construction for isolation that go against standard construction. He and I are both "geeked" out about all this as it were... While on a call for work, my brother left a message - "Hey, I was at x lumber yard and they say they have this stuff called 'quiet rock' and that it's worth n layers of drywall. check it out online and tell me what you think.." So I pop onto this forum and this was the first thread. Clear and to the point - referencing frequency ranges and their levels of isolation at each frequency. So here's a bump and nod to all that posted on this. thanks. marc

Glad we caught you before you wasted your money, cram. Doing a search for "quietrock" (one word) will yield lots of similar testimony. --Keith :mrgreen: