Real-world noise test: QuietRock plus Green Glue walls

Can soundproofing hacks reduce loud noise in an old home?

Several years ago, I moved into a 1950s apartment building. And I discovered one of the downsides of living in typical mid-century housing. A lot of wood-framed houses are hollow and noisy. They’re not a solid fortress against weather and noise, but more like living inside an IKEA wardrobe. Although construction requirements have improved in recent years, if you live in an older building, you have some fixing to do.

So I decided to research how to hack the noise problems in my apartment. I focused on the bedroom, since it was essential for sleep. This led to a number of experiments, which I did in increments.

The experiments:

Blowing insulation into just one wall. (Eventually, I insulated all the walls)
Replacing some of the original 1/2-inch drywall with 5/8-inch QuietRock drywall
Adding an additional layer of drywall over some of the other original drywall (in this case, QuietRock 510), with a layer of Green Glue in-between.

At the time, I made a couple of brief (but not lo-res) videos to demonstrate the sonic differences between the hollow drywall and the new, quieter drywall. In 2009, I also wrote about this experience in “Soundproofing for Urban People.”

Did the hacks work?

Fast forward to 2020, where I endured several weeks of major road construction right under my windows. It began at 7 a.m. every morning and continued all day long. The outdoor noise ranged from 80 decibels to over 100 decibels. Would my insulation and upgraded drywall provide me some solace?

I decided to measure the results, which you can see in this video.

And here’s another shorter video, this time focusing on jackhammering in particular, and the difference in noise and decibels between the “unsoundproofed” front room and the room with QuietRock and Green Glue. In this case, the difference between the rooms was 14 decibels:

San Francisco acoustician Nathan Sibon said in Soundproofist episode 13 that apartment hacks like mine “just get rid of a few deficiencies.” My hacks won’t be as fantastic as moving into a brand-new building that was designed to meet modern noise requirements. But they’re definitely an improvement.

And some noises — especially very deep, low-frequency drone sounds — didn’t mute as much as I’d hoped. But the 10-decibel noise reduction made a huge difference, especially working from home! Was it worth it? YES. Would I do it differently the next time? A little, but I’d rather focus on some remaining weak points, like the windows.