Maybe it’s the whine of power tools in your shop, the hum of the Cuisinart in your kitchen, or the ululations of MTV in your kid’s room. Whatever the case, everyone in the family would probably be a lot happier if those sounds were confined to the rooms where they originate.
Unfortunately, the walls in most homes are built for economy, not for confining sounds to their sources. If the noise problem in your home is really severe, you probably need professional help. You can find it in the Yellow pages under acoustical Contractors, acoustical consultants, acoustical materials and noise pollution control.
On the other hand, you may be able to solve your problems yourself by changing the way the walls in your home are built. One way to build a fairly effective noise-reducing wall without exotic materials or techniques is shown in the accompanying sketch. Compared with a standard stud wall, it reduces noise transmission by almost 80 percent, and it does this in four ways:
1. There’s no direct transmission.
With an ordinary wall, noise on one side hits the wall face and is transmitted through the studs to the opposite face. That can’t happen with this wall because it’s actually two separate walls. Notice that the sole plate and the cap are 2-by-6 stock, while the wall studs are only 2-by-4s.
These studs are installed in two sets, one set for each face of the wall, so there’s no direct link through the wall. Noise hitting one face travels through the studs supporting that face, but comes to a dead end inside the wall.
2. The wall is insulated.
Inside the wall is a blanket of two-inch mineral wool insulation. It’s not there to retain it, but rather to absorb sound.
3. The wall faces are extra dense.
Instead of the usual wall face of either paneling or a single sheet of wallboard, this wall has two-layer faces of both drywall and hardboard paneling. Both these materials are dense and effective at blocking sound. Using them together just increases this effect.
You could, if you like, get slightly better performance by using two layers of wallboard on each face instead of the drywall/paneling combo. But by using paneling, you get a prefinished wall, without the bother of taping and painting or papering.
4. Gaps around the perimeter of the wall are caulked to prevent sound from leaking through.
How To Use It
There are three ways to put this type of wall construction to work. You can use it to put a barrier around a noisy room, to build a quiet room isolated from the rest of your house or you can use it throughout your home to help create an entire ”quiet house.”
In any case, the wall alone won’t do the whole job. For it to be effective, you’ll also have to pay attention to a variety of small details that can sabotage much of your efforts to cut noise.
Avoid back-to-back electrical boxes, interconnected heating ducts, ceiling-mounted lamps, recessed wall cabinets or any other gaps that can allow the easy passage of sound. Install the paneling with adhesive, running continuous beads along both edges of the seams in the wallboard, and the paneling. Stagger the joints in the paneling so they don’t coincide with those of the wallboard. Caulking and installing moldings where walls intersect or butt into floors and ceilings will also help.
Sound can easily pass through overhead joist spaces so insulating up there and adding an extra layer of wallboard plus acoustical tile to the ceiling can help block this noise escape route. Carpets, heavy drapes, tapestries, and soft furniture on both sides of the wall can also help absorb sound.
If there is a door through the wall, it should be as thick and as heavy as possible. Avoid hollow core doors. They are like double drumheads, transmitting noise with little attenuation. You can increase the performance of any door by facing it with dense materials, and by weather-stripping.