Talking Walls: Just Say No to Noise
QUESTION: Noise seems to pass right through the walls between rooms. I am planning an efficient room addition for a home theater. Should I also insulate the interior walls to block sound? Any other tips?
ANSWER: With the proper wall insulation and construction methods, you can make your rooms whisper quiet, both from outdoors and between rooms. Just packing the wall with standard insulation will not be adequate.
For your home theater or other rooms, you can install attractive acoustical-quality wall coverings (attaches like ordinary wallpaper) to deaden noise. These special olefin-based materials block room-to-room noise somewhat but are most effective for deadening noise within a room.
New attractive wall sound-deadening kits, Snap-Trak and Fabric Wallmount Systems, use channels mounted at the top and bottom to hang any decorative wall fabric. Special insulating pads can be mounted behind the fabric to also even out old wavy walls.
The most soundproof exterior wall designs are also the most energy efficient, so you will protect both your ears and your wallet. The quietest design uses staggered-stud construction.
A staggered-stud wall has a wider base plate. The studs are alternately positioned against the interior or exterior wall surface. No stud actually touches both walls, so there is no direct sound path.
The best staggered-stud design has separate base plates with insulation snaked through the stud-to-wall gaps along the entire length. This leaves no gaps to let noise through.
To build a wall of almost standard thickness, nail long resilient metal channels horizontally on the studs. Attach the drywall to the channels. Because the channels are resilient, they deaden noise transmission.
A wall that is physically heavy blocks bass sounds, like your kids’ CD player. This is easily accomplished by using two drywall layers. Stagger the joints to block any direct sound leaks. This is a simple method to soundproof existing walls without losing much floor space.
The sound transmission class is used to compare quietness of various walls. As a reference, you can hear normal speech through a wall with an class rating of 25. At 42, loud speech is audible as a murmur. A staggered stud wall has a rating of 60, and a resilient channel wall has a rating of 50.
It also helps to run separate heating ducts to each room. This blocks a direct noise path between rooms, and it is more efficient. Stagger electric outlets in common walls so they are not directly opposite one another.
Write for or instant download (https://www.dulley.com) Update Bulletin No. 551 showing 18 soundproof wall designs, class ratings, recommended room-to-room ratings, manufacturers of soundproofing products and soundproofing tips. Please include $3 and a business-size self-addressed envelope and mail to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.
Let There Be Light, and Do It Yourself
Q: My closet has a light fixture with a pull string hanging from the ceiling. It is hard to find the string. I got so frustrated once, I yanked it right off the fixture. How can I attach a wall switch?
A: You have several options. The easiest is to buy a remote switch at your hardware store. You just screw the receiver into the light socket and screw the bulb into it. Mount the transmitter switch anywhere on the wall.
You can also buy a motion-sensing device that screws into the fixture. This will switch on the light whenever you open the door. If you are handy with tools, use grounded two-conductor NM wire and install a regular wall switch.
Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.