Two great products work great together.
As I've mentioned before, I'm experimenting around with ways to reduce some of the noise problems in my apartment on a tight budget. I think I've found the best combination to date: adding a layer of QuietRock 510 over an existing layer of gypsum drywall with a layer of Green Glue inbetween.This was sort of the best of both worlds: taking a pre-made, sound-dampened drywall and then adding it over a powerful, viscous layer of glue....onto drywall that was already on the wall studs. No demo needed. In this project, I basically added two sound-dampening layers to the original 1950s drywall (one layer in the QuietRock and the other layer created by the Green Glue) to address "flanking noise": feet, furniture, and shoes pounding on the bare floor of my downstairs neighbors' apartment. The amount of banging, bashing, and foot-stomping sounds coming from their very "wooden" apartment has been severe, and I've had a hard time finding information about how to deal with noise that comes from below. Most sound solutions are for people who live underneath noisy upstairs neighbors, while I have the opposite issue.
I found the results very effective. The walls feel as solid as concrete, and the impact noise from my neighbors has been reduced to coming through my floor joists and not through my wall studs. It also muted the sound of their closet door rolling open and shut beneath me. (I still want to solve the floor problem.) The entire room now has Quiet Rock walls in it: two of the walls have a single layer of QuietRock 525 (the 5/8" QuietRock that has a concrete-like layer on it), while the other two walls now have double drywall, with the top layers comprised of QuietRock 510 and Green Glue.
How to buy what you need
I ordered the Green Glue online by the tube from Super Soundproofing, and bought the QuietRock locally (in San Francisco, at SF Gravel Company at Berry and King Streets -- note that in 2018, this company no longer exists). You can also call QuietSolution to find out who sells QuietRock drywall in your area.The cost was relatively low: the sheets of QuietRock were less than $50 apiece, the Green Glue was about $17 per tube (I didn't have to buy an entire case of it), and the process of adding the additional wall, caulking, and mudding over it was less than if I had demolished the existing wall and started over.
What to expect
I've made a short video here to show the difference between the original wall, then the new wall two days later, and again two weeks later. I've read that Green Glue takes 3-4 weeks to "cure," so its dampening powers could potentially improve even more. Highly recommended, and in my opinion, more effective than just screwing QuietRock onto your wall studs.Some people have commented that it seems like I wasn't knocking hard enough on the QuietRock wall to show the difference. I dug up a few other bits of video that hopefully shows more convincing knocks.
Update in 2021: I've made a video that shows measurable results for this room and how it performed during a very loud, external street-construction project. I measured the noise in the QuietRock room and compared it to the decibel levels in the un-soundproofed room. Here's the story:
Thanks. This is awesome. No one does the comparison as all reports are done by the respective companies so they don't want to suggest combining the products. 2 years on are you still happy?
ReplyDeleteVery happy. I wish I could also do the same process in the front room. But due to some design quirks in that room, the effort would be considerable. I also did it in my laundry room. What a difference it made.
DeleteI'm still happy with the results even four years later. There's a lot of construction in my neighborhood and I can go into this room to reduce the noise to a bare minimum. I still have the original ceiling and a non-soundproofed window, but the thick walls, the insulation, and the quality of the materials make a huge difference.
ReplyDeleteFor the green glue, do you still use screws to attach the drywall, or do you let the glue do the work?
ReplyDeleteI'm contemplating doing the same - I have quietrock 510 and GG, planning on using it over existing drywall.
ReplyDeleteI also have a layer of OSB - can I put GG on the quietrock and osb on top of that? So it'll be drywall -> GG -> QuietRock 510 -> GG -> OSB. Or does that not make a big difference?
I'm contemplating doing the same - I have quietrock 510 and GG, planning on using it over existing drywall.
ReplyDeleteI also have a layer of OSB - can I put GG on the quietrock and osb on top of that? So it'll be drywall -> GG -> QuietRock 510 -> GG -> OSB. Or does that not make a big difference?
Hi - you mentioned in your post comment section here that you also have insulation? Do you have insulation in the walls you soundproofed? thanks!
ReplyDeleteSorry about my delay in comments here. Yes, I have insulation in the walls. In some walls, I "blew in" fire-retardant cellulose between the studs and kept the original wall intact. Afterwards, I added the QuietRock on top of the original drywall (with Green Glue). On other walls, I did a demo and replaced the original walls with QuietRock. In those cases, I used fiberglass batts. I did the demo a few years ago. If I was to do it again now, I would use Roxul Safe 'n' Sound, a product that wasn't as easy to find a few years ago. I think it's denser, more effective, and more fire-resistant.
DeleteGreat post. Would this be effective without insulation? I've a large space and am trying to contain costs, so I'm thinking of doing QuietRock and GreenGlue on the walls and ceilings even though there's no insulation beyond that.
ReplyDeleteYou could do it, but I can't cite the difference (in STC) between insulated double-drywall and uninsulated double drywall with Green Glue. This chart from Super Soundproofing Company outlines the STC difference between similar options.
DeleteMy feeling is this: if you have the opportunity to insulated when there's only a single layer of drywall on the studs, do it then. If you add the QuietRock and then wish you had filled those hollow cavities, you'll end up having to put holes through your beautiful new walls.
You could approach this in a couple of ways.
1) Rent some equipment from Home Depot (or hire a company to do it), cut round holes into the original layer of drywall between each stud, and blow cellulose fibers into the wall cavities. Cellulose will give you more value -- avoid blowing in fiberglass. Then cover the holes with the circular cutouts and mud over them. If they're not cosmetically perfect, it won't matter -- you're about to cover them with a second layer of drywall.
2) If you don't have access to a blower or to a company that can do it for you, you could cut out horizontal strips of drywall and push insulation batting (like Roxul) through the openings between each stud, then recover the drywall cutouts. I did this in a smaller area -- it's more of a hassle, but it provided some insulation without having to do a whole demolition. And, of course, you're about to cover this area up with a second layer of drywall.
I'm less sure that simply adding QuietRock and Green Glue to the existing layer of drywall on the ceiling will effectively reduce impact noise or TV/music/conversation between floors without doing anything else. It's a bigger cavity and also floors create a lot of impact noise.