Soundproofing a Basement Wall
Q: "Will 5/8-inch drywall provide substantially more soundproofing than
I am adding a 2x4 wall in my basement. A bedroom will be on one side
of the wall, and on the other will be a large recreation/den/TV room.
Will 5/8-inch drywall provide substantially more soundproofing than
1/2-inch drywall? If so, how much more? Should I use R13 insulation or
is there something better to help dampen noise?
— Toby, Orcas, WA
Tom Silva replies: None of the tactics you mention will help deaden the sound
over that short a distance. The best solution is to build two walls out
of 2x3s, staggering the boards so that each seam falls at the center of
the board opposite it, and insulate each wall separately with
sound-deadening insulation, making sure that one wall does not touch the
other. Any outlets, as well as the door between the two rooms, will
transmit vibration and sound but if you use a solid door and
weatherstrip all four sides that should minimize sound transfer.
When the time comes to drywall, stagger the joints here too, and make sure
the panels stay 1/4 to 1/2 inch away from the ceiling or floor, which
will be picking up both rooms' vibrations. Use acoustical caulking to
seal floor and ceiling seams. Above all, keep in mind that these steps
are only sound-deadening, not soundproofing.