soundproofing for urban people

I went out for dinner this weekend at a tapas restaurant. The food was great, and the ambiance could have been great, too, if the restaurant had taken some steps to reduce noise. After all, going out for Spanish tapas should evoke feelings of pleasure, relaxation, great flavors, and a general "chilled out" environment. However, like many trendy eateries, the floors and walls were made of hard surfaces, and the sound just bounced and amplified. Every table was full of patrons -- which was great, of course. But when we walked in, we were greeted to a blast of noise. We had to yell at our table to hear each other. So I pulled out my mobile phone and checked one of my decibel-reader apps. It was 88.8 decibels. This article from Restaurant Engine states that normal conversation ranges from 55 to 65 dB, conversation gets difficult at 75 dB, and noise becomes "damaging" at 85 dB. Yet our table was clocking in at over 88 dB when we were just sitting across from each ot

I liked this video from Roxul because the presenter clearly explains the difference between the two types of noise: airborne and low-frequency noise, which I will add to here. The lower frequencies travel through the wood studs. A low frequency travels from your wall surfaces, floors, and ceilings if they sit directly on those studs. Lower frequencies include bass from your stereo, impact sounds from walking or pounding, trucks driving outside, and maybe the spin cycle on a washer. Roxul  insulation mitigates the other kind of noise -- airborne noise -- which can include talking and TV (without bass). This insulation product is dense and does a really great job of blocking airborne noise. However, if it's used alone, it doesn't stop low-frequency noise. The presenter shows how to insert Roxul batts between the studs, which you've seen before. Then he installs a resilient channel to keep the drywall from touching the wood studs. The resilient channel's job is to r

This short video from builder  Matt Risinger covers a lot of the issues we've discussed in this soundproofing blog. Matt has a show on YouTube that gives examples of successful construction projects. In this example, he shows a soundproofing project in a two-unit condo with a shared wall between them. They did everything right. The used staggered wall studs (with an 8-inch separation between the two units), Roxul batting, QuietRock on the walls, putty pads on the outlets, and Green Glue . As a test, Matt turns on a boom box in one of the rooms and measures the decibel output. Then he goes to the room on the other side of the wall to show how much of that noise leaks through and uses a decibel meter again. It's almost silent. This is what you hope to achieve, especially with new construction. But it won't happen unless you use the type of materials and processes shown here. Here's the video. Great job!

What can you hear through a "normal" wall? The average American home built after the 1940s probably uses gypsum board nailed onto wood studs over a hollow enclosure. The STC rating for that setup is 30 decibels. According to this chart , normal conversation is still audible through a 30 STC wall. That should be no surprise to some of you apartment dwellers. A single sheet of 5/8" drywall with fiberglass insulation provides an STC of about 40. You can still hear loud speech through this setup. If you use Roxul batts, you increase that STC rating to about 45. If you use a soundproof drywall (like QuietRock) and insulation, you increase the coverage to 50 STC.  Double drywall with Green Glue inbetween, plus Roxul insulation increases it to 56 STC. You can read about this at the Welk and Sons Drywall site. The cost difference is noticeable: 5/8-inch "dampened" dry wall is about $80 per sheet compared to $10, but might prevent you from having to do more s

I found a YouTube video posted by Tone N.W. and it annotates the steps he took to soundproof his bedroom ceiling after his upstairs neighbor tore out her carpeting and began walking around on bare hardwood floors above his home. As you know, hardwood floors can be your worst enemy. A hardwood floor that's nailed directly onto a subfloor and then directly on top of wood joists is like a microphone into the rest of the building, and that impact noise travels through all the framing and right into the adjacent rooms (or apartments). He said that he learned everything he needed to know from this document from The Soundproofing Company in Michigan. Here's what they did: They tore off the original drywall ceiling. It looks like a previous owner had added cross strips of wood on the joists already, and they removed those too. (If you read his notes, it sounds like he regrets the extra labor in this step.) He and his wife cut drywall and added it to the upstairs subfloor in

It's not too late to insulate.  A few years ago, most American homes had no insulation in them. When a homeowner did insulate, it was usually with fiberglass batts. Then along came some better products. One of them is blow-in cellulose insulation. Does it work? I can attest to this: YES. I've used it in walls and ceilings, and it works quite well for airborne noise. If you live in an uninsulated home and you hear your neighbors voices coming through your walls or ceilings, cellulose will dampen that noise or mute it entirely. It doesn't work for all types of noise. But it doesn't eradicate impact noise. You might still hear the sounds of someone walking across a bare hardwood floor with their shoes on, for example, or hear wall-mounted cabinets opening and closing. There are other solutions for that, and by combining different solutions you can control most structural noise and create more privacy. Low cost Blow-in insulation is inexpensive. You can hire a

This is yet another video extolling the virtues of using Roxul "Safe and Sound" insulation.  Because Rockwool is fire-resistant, you can insulate with it up to the cans that support the recessed lighting without fear of overheating the lights (and burning out the bulbs) or igniting a spark. However, any time you open a hole in your ceiling, you invite the opportunity to transmit noise between floors. Remember: if you're going to spend money on drywall, get something like QuietRock or Supress that dampens noise. This is your one chance to get it right – don't cut corners on the materials and regret it later!