A critical component of the current Urban Caribou Bed and Breakfast renovation is the soundproofing in the bedrooms. It is also one of the least exciting because at the end of the project it will look nearly identical to before we started.
We are a young family and want to be able to enjoy chasing each other around fighting dragons and rescuing princesses. Understandably, our guests don’t want to be a part of that action when they’re staying with us. We have done some significant research into the science of sound and have installed a soundproofing system in the bedroom ceilings to give our guests the option of sleeping in.
Sound transfer is a two headed monster and unless you have a plan for both types of sound transfer the results will not be good enough.
To limit the transmission of airborne sounds, like a dragon fighting battle cry, mass is your ally. To effectively eliminate this type of sound transmission you need to put mass between the source and the receptor to absorb the sound waves. In our case that is insulation in the space between the joists in the ceiling, three layers of drywall, and a noiseproofing compound called Green Glue between the final two sheets of drywall to absorb sound.
To limit the transmission of impact sounds, like little feet marching across the floor, isolation is the key. We have installed a floating ceiling to separate the bedrooms from the floor above. We ran resilient channel (a thin metal channel designed to isolate drywall from the framing) perpendicular to the joists. On the bottom side of the channel we installed 1×4” strapping (parallel to the framing again but offset into the middle of the joist space). Both the channel and strapping were installed with foam padding tape under each anchor location to further reduce sound transmission. It would have been possible to omit the 1×4” strapping except that the channel is quite narrow and anchoring two sheets of drywall into a narrow channel is challenging. If your screws miss the narrow channel or strike the wrong part of it you run the risk of re-establishing a path for impact sound transmission.
This hybrid soundproofing system involving batt insulation, 5/8″ drywall, resilient channel, 1×4″ strapping, foam padding tape, double 1/2″ drywall and Green Glue noiseproofing compound targets the reduction of both airborne and impact based sounds. A lot of thought and work has gone into giving our guests a great night of sleep. Too bad we’ll never hear about it (pun intended).