Your home is your castle, and the last thing you need is for your son’s stereo or your daughter’s phone to sound like an army of knights crashing through on their way to battle. Noise comes from sound waves, which are vibrations in the air that are generated by any physical action. If you can break, interrupt, alter or otherwise change the flow of those waves, you can change the amount of transmitted noise.
WALL CONSTRUCTION A MAJOR KEY TO QUIET
If you are building or remodeling, you have a lot of opportunities to impact noise transmission that are not available to you after the house is complete. Perhaps the most important consideration is the interior walls. The typical wall is simply a sandwich of drywall sheets over wood studs. Since drywall is a solid, relatively thin material, it does little to break the sound waves, and the air that is trapped in the wall cavities between the sheets does nothing to stop sound transmission.
One obvious solution is to install insulation in the walls between rooms, which will absorb some of those sound waves and greatly deaden the noise transmission. While any insulation is better then none, your best bet is to specify sound-deadening insulation instead of the more common thermal insulation, typically found in attics and exterior walls. Heavier and denser, this type of insulation is specifically designed for this application.
You can make a big impact with how the drywall is installed as well. The majority of drywall is installed by attaching it directly to the studs on each side of the wall, so the sound waves from one room will resonate directly through the drywall-stud-drywall composite right into the adjacent room. Installing double layers of drywall with staggered seams on each side of the wall will help to some degree, providing additional thickness and therefore additional mass to help deaden sound waves. Special sound-deadening sheets can be used as the first layer, directly under the outer drywall layer, or you can use one or two layers of 5/8-inch drywall instead of the standard 1/2-inch.
To better stop this transmission of sound, you need to break up as much of the direct connection between the drywall and the stud as possible. Perhaps the most effective way of accomplishing this is to install resilient channels, also commonly called “hat channels,” prior to installing the drywall. The U-shaped metal channels are attached horizontally across the faces of the studs, and then the drywall is attached to the metal channels instead of the studs. The staggering of the connection points and the sound-absorbing properties of the channel’s design makes a tremendous difference in how much sound transmission occurs between the walls.
Sound deadening insulation is a little more expensive then thermal insulation, but is not a major expense in the overall construction of home and will pay big dividends in peace and quiet without affecting the overall size of the wall. Double drywall layers and resilient channels are also relatively inexpensive in the overall scheme of the things, but remember that they create thicker walls, which will necessitate larger door jambs and other adjustments.
WATCH THOSE WINDOWS AND DOORS
Create an opening in a wall, and you create a pathway for more noise. For that reason, when you’re thinking about how to quiet things down, you want to pay particular attention to your windows and doors. Wood and vinyl frame windows have more sound deadening properties then metal frames, which are more prone to vibration and sound transmission. Also, the thicker the air space between the panes of glass and the better the insulation around operable windows, the better the window will perform from an acoustical as well as a thermal standpoint.
Solid-core doors are also considerably better at blocking noise then hollow-core doors, so you might want to consider upgrading to solid-core interior doors for any room where sound is an issue. Even with solid-core doors, sound can make its way around the door as well. Therefore, keep the door as closely fit to the floor as possible, use resilient materials to seal between the door frame and the wall studs prior to installing the door casing, and consider some type of weatherstripping between the door and the door stops, even on interior doors.
QUIET DOWN THE PIPES
If you have a two-story home, specify cast-iron waste lines for all upper-floor plumbing. This dense, slightly rough material is much better at deadening the sound of rushing water than the more common ABS plastic waste lines, which are smooth inside.