Sound Transmission Class (or STC) is an integer rating of how well a building partition attenuates airborne sound.
Materials which can improve STCs in walls include mass-loaded vinyl (MLV), standard drywall, “soundproof” drywall (such as QuietRock, Supress, SoundBreak, or ComfortGuard) and damping compounds such as Green Glue.
When researching solutions to soundproof a “paper-thin” wall:
Blow-in insulation / cellulose. Holes are drilled every 6-12 inches in-between each stud on the wall. A hose is inserted into the wall and the material is pumped in. This will not work if there is any existing insulating material in the wall – even if it’s 20+ year old broken down fiberglass.
Additional drywall layer. Simple, just slap up another layer of 5/8″ thick drywall. More material = more soundproofing.
Soundproof drywall. Use acoustically engineered drywall sheets instead of standard drywall. Even more soundproofing at roughly 3x the material cost.
Dampening compound. Add a dampening compound between two layers of drywall to increase the soundproofing.
Depending on who you talk to you will receive a different recommendation. We unfortunately found out about the cellulose limitations during an aborted installation. This led to an evaluation of removing the drywall to change the insulation, or figuring out a plan “C”.
So how do you figure out what to do? First figure out the STC rating that you want to achieve. In my case I’m looking for a rating of at least 50 and anything approaching 60 would be ideal. I found a Wall Assembly Performance guide on GreenGlue’s website with some fantastic comparisons of installations. Additionally on the QuietRock site they list an STC Rating of 53 on their highest performing product.
1 layer of drywall each side: 40
2 layers of drywall + 1 layer of drywall: 42 <– Adding one extra drywall layer to one of the walls
2 layers of drywall on both sides + 1 layer of Green Glue per side: 55 <– Can’t install since there is no access to one of the sides.
1 layer of QuietRock one side: 53 <– This assumes that the original drywall was removed
Unfortunately STC ratings are not additive and increase slowly with each additional layer. In our case we’ve decided to add a layer of GreenGlue and a layer of QuietRock. I’m hoping this achieves an effective rating of 55+.
Install a layer of QuietRock drywall with a layer of GreenGlue to the existing wall.
It never ceases to amaze me how often things in life will turn full circle. This blog is definitely one of those “things” for me. I’ve been wondering what to do with this blog for some time now and think I’ve finally figured it out…
Back to Basics
Longer form writing will be the my focus here. Short thoughts will go to my twitter, and occasional published imagery will go to flickr. There won’t be any specific theme, just the stuff that interests me.
# Quick way to rebuild the Launch Services database and get rid
# of duplicates in the Open With submenu.
alias fixopenwith=/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user
I’ve been off Verizon FiOS for exactly an hour and I already miss it. I would have never guessed that I would consider a 30ms hop to the GPON as good speed, but after seeing what Time Warner Cable is doing anything would be better. I’m going to have to climb on the roof later and figure out what I have line of sight to for a P2P RF link.
For the record I’ve like Apple’s new Maps application. So much so that I’ve stopped using my onboard navigation in my car. Granted I’ve found problems with missing data, typically this surfaces when I am looking for a destination by a common name and not a street address. The speed, GPS, turn by turn navigation, vector tiles, and offline cache have all outweighed the negatives I’ve encountered.
Tonight Google released Google Maps for iOS, and my initial impression is that it’s absolutely fantastic. Early reviews highlight the lack of a on-phone cache (this will be a problem for me when I’m using the phone while using Maps for directions) which I’ll test and find out for sure on my way to the office in the morning. The application seems to be beautifully executed: fast data loading, smooth scrolling, responsive, turn by turn directions, etc…
Like or hate Apple Maps one thing is for certain – without it Google would have never been pushed to release what we have now. A little competition can be a good thing.
It’s actually making me crazy that I’m saturating our office firewall at 822 Mbps. I’m trying to convince myself to not worry about it, and that 822 Mbps is really, really fast, but this might turn into a “thing” that I’m not going to be able to leave alone.
iMac:~ mclark$ iperf -c iperf.phyber.com
Client connecting to iperf.phyber.com, TCP port 5001
TCP window size: 129 KByte (default)
[ 5] local 184.108.40.206 port 58948 connected with 220.127.116.11 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-10.0 sec 980 MBytes 822 Mbits/sec