Home & Garden Columns

About the House: Some Cures for Noisy Neighbors

By Matt Cantor
Thursday October 09, 2008 - 09:50:00 AM

A friend of mine has a bass guitarist living upstairs who has been working out the chords to “In a Gadda Da Vida” for the past 12 years. My friend is a patient person but she’s begun to exhibit something of a tic and often looks dolefully into space for long periods of time, returning from her reverie only when the music has stopped for some short spell. 

Recently she’s begun asking a lot of unwholesome questions about firearms and those CIA poisoning tricks they used to talk about in the sixties (probably while “In a Gadda Da Vida” was playing in the background).  

I have suggested that she might want to try some sound control techniques in the building before moving on to anything more rash. Noise conduction problems can be complex and modifications designed to reduce sound in buildings can be expensive, but if that cute little freckly kid from next door has grown into a 17- year-old drummer in a band called TRåMA, you might also benefit from some of these notions. So here goes. 

If your problem is noise transmitted between the upstairs neighbor’s floor and your ceiling, one of the best techniques is to replace the existing ceiling with new a layer of drywall (I’d use 5/8”), suspended by resilient channel (often called rezi channel). These are Z-shaped pieces of metal that come in 10-foot lengths that are screwed onto the bare rafters of a ceiling (or over an existing ceiling), then covered with a layer of drywall (aka sheetrock).  

To make these, a long strip of metal is taken and folded twice along its length, forming a strong bar that forms a tiny Z-shape when viewed from one end. 

The channels are installed perpendicular to the floor joists so that they run across the bottom edge of the joists from one wall to the other. The new drywall ceiling is then attached to the metal strips, not to the ceiling above. (The “Z” shape of the channel also gives the drywall a bit of bounce.) The result is that your ceiling will transmit far less of the sound emanating through the musician’s or tap dancer’s floor above. 

If you have plenty of ceiling height, it’s fine to leave the first layer of drywall, although testing by National Research Council Canada suggests that this is not a good technique. (Hmm. Is it fine, or not a good technique? If not good, might as well not mention?)  

If you like, you can enhance this methodology in several ways. You can insulate the space between the joists using common insulation. You can install Sound Board, a thick fibrous cellulose matting. You can also install this material across the bottom of the joists prior to installing the resilient channel but remember that you’ll need longer screws. It’s a good idea to use 5/8” drywall on the ceiling if you want to really kill those bad vibes. 

For the really serious isolationist, cement tile-backer can be used as a part of such an assembly, although this is probably more effective for high frequencies than for low ones. You’ll want to remember to bring the launch codes with you when you lock down for the night. 

Sound channel, insulation, or additional layers of drywall can also be used to subdue noise that emanates through walls, but the best method in my opinion involves building one of two types of party walls. My favorite involves actually rebuilding the wall between the two spaces. You build a wall with two sets of studs (upright 2x4’s) on a 2x6 bottom and top member. One set of 2x4’s is built to one edge of the 2x6 facing one room. The other set is built to the other edge facing the other room. The uprights alternate along the length of the 2x6 plates or sills, each one touching only one side of the wall. 

So when you hit the wall on one side (or strike a power chord), one set of 2x4’s will vibrate but not the opposing set of 2x4’s and drywall finish. Although this technique is quite helpful for loud noises and banging, it’s ideal demonstration is in virtually eliminating normal talking and the other sounds of life. 

I used this technique in a duplex in Richmond many years ago and when we were done, we could holler on one side and hear virtually nothing on the other. Great for privacy during marital disputes or intimate moments. 

The second type of party wall is simply a second wall built almost against the first with one or two layers of drywall between. This eats up another few inches of room space and seems less efficient than the staggered technique. Nonetheless, it is simple and can be added to an existing wall while the previous method requires building a new wall from scratch. 

For sounds next door (like TråMA’s weekly band practice), there’s nothing quite like double-glazed windows. It’s impressive how well these advents of modern building science inhibit sound. About 12 years ago, I was inspecting a small house built right beside the 580 freeway. It was up a small hill so that you looked right over onto the freeway and the hill acted like an amphitheater, capturing and funneling the sound right toward the house. Outside the house, the freeway noise drowned our best efforts at conversation, but when we walked into the house—recently fitted with these new-fangled windows—the sound was little more than a distant hum.  

This works equally well for neighbors who fight, dogs that bark all night or whatever drives you to and beyond distraction. If you work nights and sleep days, double-paned windows just might keep you sane. 

I should also mention that carpeting with thick padding is a great sound absorber and requires no significant alteration to the building. 

I’ll add one last measure for the band members. If you live at Mom’s or if the police have now been at your house more than four times, you might try the following technique. 

Drum kits can be placed on a floating floor or even in a hanging room-within-a-room.  

You can build a floor that sits above the primary floor in the room and either place it on rubber isolation bumpers or suspend it from the ceiling by use of cables or threaded rod. The secondary floor need be suspended only a fraction of an inch above the original floor to prevent transmission of the vibration from a drum kit. The hangers (rods or cables) can employ isolation devices like the one mentioned above to connect them to the ceiling.  

Bumpers can be found at industrial supply stores. I suggested these bumpers when my 0steopath and friend, Catherine, was being assaulted by the vibration from a restaurant ventilation system that ran upward through her offices. The intensely close attention required to study her patient’s sounds and movements were simply too hard to achieve with the entire building bombilating like a cicada. This simple and inexpensive method worked wonders by isolating the rooftop ventilator and eased tensions between the resonating parties. 

This was by no means a complete list of sound reduction techniques but, hopefully, one or more of these techniques will get you and your neighbors started on the road to concord.  

So, in closing, if the person you’re sharing the duplex with starts a Herman’s Hermits cover band, remember, don’t get mad; don’t get even; just get resilient.