Expert: Richard Taylor, AIA - 2/5/2004

Question
I live in an attached house and can hear my neighbours' TV etc. Would cavity wall insulation reduce this nuisance much?
Many thanks, Steve

Answer
Steve:

Thanks for your question!

Sound is transmitted through building materials in several ways, and can be attentuated in several ways.

Insulating the wall cavity will reduce the airborne sound somewhat, perhaps enough to block out the TV next door.  But some sound will still make its way into your home through gaps in the wall construction and space around electrical outlets.  Blocking those with acoustic caulk will help solve that problem.

Sound also gets in by causing the wall materials to vibrate and this can't be reduced by insulation.  If you still hear too much noise after using the techniques above, you'll have to isolate building materials from each other.  Unfortunately, this is a larger-scale exercise.  But if you're planning on opening up the wall to insulate it, it won't be much more effort or expense.

Isolating the materials means creating a separation between your side of the wall and theirs, so that sound can't be transmitted by vibration.  The easiest way is to remove the drywall (or other wall surface) on your side and attach resilient channels to the studs on your side of the wall.  These channels are flexible and will hold the new drywall away from the studs - so that when the TV sound vibrates the wall materials on your neighbor's side, the vibrations are attenuated by the channels before it reaches your side.

There are other techniques but they're much more involved.  For more information about sound insulation and attenuation, go to www.usg.com (United States Gypsum) and look under sound insulation.  They'll tell you about materials and techniques that will do what I've described above.  The materials you'll need should be available from any building supply store.

Hope this helps!

Richard Taylor, AIA
Richard Taylor Architects, LLC
www.rtaylorarchitects.com