Soundproofing a Common Wall
The goal with any common wall soundproofing project should be to add density to the surface and disconnect how the wall is assembled. This will force the collapse of the transmitting sound wave inside your common wall, and trigger up to a 90% collapse in sound bleed. This is our most common request for a soundproofing treatment, and targets our top selling product dB-Bloc.
Density. We start with density. Think of the top of a wine glass, the face of a drum, a guitar string or a tuning fork. If these objects are allowed to vibrate, they will produce sound. But if you place your hand against them, the sound dies because the objects can no longer vibrate freely. Adding mass to a surface impedes resonance.
The same holds true for your common wall. Standard construction produces walls that aren't dense enough to kill sound vibrations. Adding density to the surface will increase your wall's ability to force the collapse of the vibration, just like the top of your wine glass. The sound deadening membrane is called dB-Bloc, and can be layered to your existing finished wall.
Disconnection. Next comes your disconnection. The framing inside most walls is a single frame construction supporting drywall on both sides. The frame serves to connect your rooms together much like a string pulled tight between two coffee cans. The same holds true for the common joists in a common floor/ceiling assembly. Sound passes structurally by vibration through your connection points.
The goal with soundproofing your wall is to disconnect your framing, and force the collapse of the transmitting vibrations to happen inside your wall assembly. The equivalent of cutting the string that is otherwise pulled tight between two coffee cans.
Installing This Layering System. The soundproofing treatment is far easier than most clients realize. By simply stapling dB-Bloc to your current surface, running a horizontal set of furring strips up the wall, and adding a new layer of drywall to the face of your furring strips, you've got it. The wall thickens up by maybe 1.5", but can force the collapse now of up to 90% of the noise that wouls otherwise vibrate straight through your wall assembly.
Your Wall Soundproofing Treatment:
Your ultimate goal is to impair the wall's ability to conduct vibration. This is accomplished by adding two components to your wall assembly. The first is density, the second is disconnection. The combination of these two ingredients will help force the collapse of your sound wave inside your common wall, and can trigger up to a 90% drop in sound transmission. Your treatment will depend on your starting point, your results will depend on leakage. Ventilation, plumbing, electrical, floor, ceiling, adjacent walls, windows, stairwells and a host of other flanking paths will seep noise and decay results. For this reason, plesae note there is no "cure" for noise bleed, only better "control". The disconnection you force in your wall system depends on your starting point. For more information, click which is yours:
Your Acoustic Results
As we simulate in our Sound Chamber, this sound insulation treatment can reasonably trigger a 10-12 dB drop in noise levels bleeding through a common wall. Much of the success of a sound isolation wall will depend on the quality of the installation, the disconnected framing techniques, the frequency of the sound source, and the number of holes in your wall surface that will impair your noise reduction efforts. Please note, even if we trigger a 90% collapse in bleed straight through the wall, the overall results will be less due to flanking paths that will allow noise to circumvent your treatment. Think of combatting sound bleed as a step to better "control" the bleed, not "cure" it.
Open air holes in a wall are called "flanking" paths for , and will serve to deteriorate results. They include switch plates, electrical outlets, supply vents, return vents, light cannisters, pipes, windows, doors, and a host of other possible paths that can not block noise bleed. For soundproofing common walls, If you frame the wall properly, line it with dB-Bloc, and minimize the flanking paths, you can trigger up to a 90% drop in noise bleeding through.
Tips for Soundproofing a Wall:
Start by setting your expectation levels accordingly. Nothing will produce a 100% drop in sound transmission through a common wall. If our treatment can deliver a 70-90% drop, you should be more than satisfied. The most difficult sounds to isolate and contain are impact sounds (a drum beat) and low bass tones (subwoofers, jet engines, bass guitars). These sound sources contain long, flat soundwaves that travel over less time and distance than mid to high pitched sounds.
dB-Bloc can be mechanically fastened to your surface, new or existing, with a staple gun or sheetrock screws. The material is too limp and heavy to use adhesives. Overlap the material 1-2" and place a bead of acoustic caulk along the joints where your wall meets the ceiling, floor or adjacent walls.
Firring strips can be simple slats of wood, say 1x4s from your local building supply center, or more mechanical metal channel systems. The RSIC Clips work well to deliver the disconnection you need also. If your wall is concrete, apply the firring strip first, then the dB-Bloc and the sheetrock. This will lift the density of dB-Bloc away from the density of your concrete wall, and create an air gap where the soundwave can collapse. If your wall is wood or metal frame, apply dB-Bloc first, then the firring strip and the drywall.
While our test results are triggered using a single layer of dB-Bloc. many clients opt to double up on the treatment. If you do, be sure to separate the two layers of dB-Bloc, don't place the layers together. You can fasten the material to both sides of the wall, or on both sides of the firring strip layer. This will NOT double your result, but can trigger another 3-5 dB drop, and might be worth the added expense depending on your budget and your goals.
We also recommend that for those clients who want to double up on the drywall, vary the thickness. If you repeat the same thickness of drywall, you attack the same frequency pitch of noise twice. But if you vary the thickness of your drywall, you will attack two different frequency pitches of sound because you are working with two products of different densities. Again, our test results are for a single layer of dB-Bloc and a single layer of drywall. These added steps are not necessary, but can help further lower your sound bleed. Consider lining the popular damping material Green Glue between your two drywall layers for added protection against sound bleed.
Allow 7-10 days to deliver dB-Bloc. The material is very dense, each 54" x 30' roll weighs 150 pounds. If you have more questions after reading the tips for soundproofing your wall, call our help desk at 1-800-638-9355.