A Client of mine has two units in an old Victorian and wanted better soundproofing between the ceiling and floors of the two units.  In these old houses, there is usually a crawl space, no insulation and floor boards with a basic framework of  drywall and/or lathe and plaster stuck attached to it.  The end result is that you hear everything.  So some research was done as to what is the best solution out there and being mindful of costs.  It came down between doing a standard drywall ceiling using RC channel vs. a new product called QuietRock™ soundproofing panels…

How Sound Travels

Sound travels in waves and when sound waves hit rigid structures as drywall, it will vibrate and transmit through the framework and radiate throughout.  There is nothing to isolate or to absorb sound waves, in fact, if there is ductwork in between the ceiling joists, those too will transmit the sound.

Two options are out there today that are popular–RC (Resilient Channel) ceiling and QuietRock sound proof panels.  The latter is gaining in popularity but is very costly.  Thus we did the research on both so that an educated Client can make a decision on which type of soundproofing investment they want to make.   My research is a blend of information from the Internet, talking to drywall installers, store vendors and eventually to Serious Materials, the makers of QuietRock™

Option #1: In this corner…RC Channel plus Sheetrock

RC Channel stands for Resilient Channel and its use with sheetrock has been around longer.  The RC system will dampen the sound but not totally soundproof the rooms.  RC channel are inserted between the drywall and the studwork, leaving a small air gap acting as a shock absorber.  This greatly reduces the vibrations from being passed from one material to another.  You can also use an absorbent mat to cushion the channel and drywall to have an extra layer of absorbency.  It is also recommended to put insulation between the studs to do the same.

Cost-wise, there is more labor than traditional installation of drywall.  The RC Channel itself cost is not bad.  It’s best to use someone who has installed this properly before.  Most drywall installers prefer this system because they can easily cut the drywall.  Read more about soundproofing with RC Channels

Option #2: In the Other Corner…QuietRock™

QuietRock panels are made by a company called Serious Materials out of Sunnyvale, CA. and has gained alot of traction for use in home theater systems, commercial spaces, et al and the rub is that it is very expensive.  Here, in SF, a 4×8′ panel of QuietRock 525 costs about $65/panel…ouch.

The QuietRock technology is impressive, and they claim it can muffle up to 90% of the noise with normal insulation accompaniment.  The panels are made of a tough silicate board with a layer of polymer between the board and the gypsum.  It comes in various thickness, depending on the application.  For acoustical barrier between wood studs on ceiling/floor, they recommend the 525 panel.  On their website, they offer a Hear the Difference page–check it out.

Cost-wise, it costs about $65/panel in SF just for material alone.  Additionally, they recommend using QuietSeal which is a soundproof sealant for all joints and QuietPutty to go around junction boxes, etc.  The various sealant and putties costs about $20 and $10 respectively.

Labor-wise, although QuietRock says it is cheaper to install than RC channel, my drywall guy said it is harder to cut because of the thickness of the board.  So, I think it may be a wash on the labor.  But on the material, definitely more expensive and it all depends on what type of investment you want to make towards soundproofing.