Common Walls

Preventing noise bleed through a common wall is the goal of one of the most frequently sought soundproofing endeavors. The issue of unwanted noise transmission through common walls occurs in the same way whether the application is residential, industrial, or commercial. To implement the sound reduction techniques that adequately prevent noise from traveling through common walls in a home, office or industrial setting, understanding why noise travels throughout a home or building in the first place is beneficial.

What we interpret as the sound is simply a collection of structured vibrations that travel from molecule to molecule through media such as air and water as well as solids such as wood, concrete, and glass. Untreated common walls between rooms are not generally equipped to prevent noise transmission between the rooms, and in fact, tend to provide an ideal common surface through which sound can easily travel. Therefore, the goal of controlling sound transmission between rooms is to inhibit the ability of sound waves to pass through these common surfaces and into adjoining rooms.

Reducing the transmission of sound waves through the walls of a room involves isolating the room by increasing the density of the structure and establishing a disconnection from the original wall. An effective way to increase density is to line each wall in a room with a mass loaded vinyl such as dB-Bloc, which is a heavy membrane designed to be stapled or screwed over the entire wall surface. Adding density to a wall reduces its ability to vibrate, thus reducing the ability for sound vibrations to pass through.

The second phase of isolating a room to reduce sound transmission through its walls is establishing a disconnection from the original wall surface. The common walls adjoining one room to the next provides a means for sound waves to travel directly through the surface and into the next room. By creating a second surface and thus space between the walls, this treatment can force sound waves to collapse between the walls and significantly reduce the amount of noise that is audible in the next room. Creating a secondary wall surface involves affixing evenly spaced horizontal furring strips from floor to ceiling, and adding a new layer of drywall in front of each wall of the room.

Additional measures, such as sealing joints among walls, floors, and ceilings with acoustic caulk and doubling up on the density + disconnection method described above can increase the effectiveness of a wall sound proofing project. For example, using two separated (not touching) layers of dB-Bloc and creating a third layer of drywall at a different depth than the second can improve the results that can be expected from a wall soundproofing project. The method of increasing density and disconnecting wall surfaces is extremely effective for sound reduction, though no treatment will generate a 100 percent reduction in sound transmission through common walls.

The need for wall soundproofing treatments spans a wide range of applications, such as homes, doctor’s offices, school classrooms, sanctuaries, and countless others. At the inception of any soundproofing project, consulting with a knowledgeable soundproofing professional is recommended to ensure that all variables are considered and the most effective treatment is applied.