Soundproofing Made Simple
Many years ago, we were hired to do a construction job for a couple of gentlemen who wanted their offices at the penthouse level of their seven-story commercial building. But, the space was immediately adjacent to a huge “chiller” that supplied air conditioning to this enormous building.
Needless to say, it was noisier than all get out and would make the space uninhabitable.
Fortunately, they engaged the services of an architect and acoustical engineer who designed a soundproofing technique that took the chiller out of play. The gentlemen ended up with dynamic office space and we walked away with our first and most enduring lesson on soundproofing.
Though you may not have a chiller to deal with, a neighbor’s barking dog, a teenage band practicing down the street or even a loud stereo or television in the next room are all potential sources of unwanted noise that could be disturbing. And the prospect of enduring unwanted noise increases significantly if you live in a condominium or apartment and share a wall, floor or ceiling with one or more units.
There are ways to deal with noise pollution. However, keep in mind that soundproofing your home from unwanted noise can range from a few simple improvements to a complex undertaking, depending upon the construction of your home and the origin of the noise. In any case, its important to know that there are only three principles that stop noise — space, mass and dampening.
Space: The more space, the more the noise reduction. For example, you are less likely to be bothered by noise from freeway traffic the farther away your home is located from the freeway.
Mass: All else being equal, the thicker the construction material (or assemblage), the more the mass, the more likely it is to reduce the transmission of noise. For example, a 2-by-6 wall with two layers of 5/8-inch wallboard on either side has more mass than does its 2-by-4 counterpart with a single layer of 1/2-inch on either side. A block or solid concrete wall can have still better soundproofing qualities.
Dampening: This essentially involves preventing sound transmission by inhibiting vibration. Dampening is sort of the “shock absorber” of the soundproofing world.
Keep in mind that as you endeavor to soundproof your home, noise reduction differs from noise absorption. Noise reduction acts to stop the noise before it gets to you (or the room you are in) by utilizing space, mass and/or dampening. Where noise reduction deals with noise outside of a room, noise absorption attempts to change the characteristics of the noise within a room by utilizing sound deadening materials such as carpet, upholstered furniture, acoustic wall and ceiling treatment and fabric window coverings. You may be need to do a little of both.
Noise enters the home through windows and doors. Walls are always better at stopping noise than windows. So, the first place to look is your windows and glass doors. Whether you have the older single pane windows or the newer dual pane windows, you can do more to stop the noise.
Replacing single pane windows with soundproof window treatments will improve both energy efficiency and comfort — and take a step toward soundproofing, albeit small. Storm windows can further improve soundproofing, but results will vary according to style and quality.
An increasingly popular method of soundproofing windows and sliding glass doors involves installing a second window inside your existing window or sliding patio door. This eliminates the need for window replacement and the second window opens and closes just like the existing window for ventilation and egress. However, when closed, the window adds an effective sound barrier and air space that helps cut down on noise and energy costs.
When it comes to walls, adding a layer of wallboard can go a long way in soundproofing a wall by increasing its mass. Before you head out to the home center, consider using 5/8-inch material instead of 1/2-inch or for the ultimate in soundproofing have a look into wallboard with a thin lead core. It can be pricey, but worth the investment.
Before hanging the wallboard, install a continuous, generous bead of silicone caulk where the wallboard attaches to the framing – vertically at all stud locations and horizontally at top and bottom plates. The silicone will act to inhibit vibration and dampen sound. In addition, the silicone will create a shallow air space between the two layers of wallboard that will further improve the soundproofing characteristics.
Attach the wallboard using construction screws rather than nails to minimize the number of holes. Using this technique, a single added layer of wallboard employs all three principles of stopping noise.
If you will be building new walls, “party wall” construction is an excellent means of soundproofing. An example of party wall construction consists of 2-by-6 top and sole plates with 2-by-4 studs that are staggered and held to the outside face of the plates. Often the plates are split to create a space that inhibits vibration and acts to dampen sound. The “additional layer of wallboard” technique described earlier can also be used in conjunction with party wall construction for a super soundproof configuration. Consult an architect or engineer for a party wall detail that best suits your needs.
Soundproofing a ceiling (where there is an attic above) can be as simple as adding a layer of wallboard – provided that the ceiling joist will carry the added load. The ceiling framing may require a bit of beefing-up first. Check with an engineer or you may end up with a sagging ceiling.
Soundproofing a ceiling with a floor above can be a bit more complex. The wallboard trick will work well when installed over resilient channel. This is a piece of continuous metal channel in the shape of a “Z” that is designed to inhibit the transfer of vibration and sound throughout a structure. It can be fastened to raw framing or to an existing ceiling finished with wallboard or plaster. For more information on soundproofing visit Soundproofing101