One of the most common soundproofing treatment requests we receive is battling the noise transmission through a common floor/ceiling assembly. Foot noise down through, or noise bleeding up, in either case, the goal with the treatment is to produce more privacy upstairs and down.
The success to treating common floor/ceiling assemby noise surprises most. The key is to sever the connection points as best you can and line with density. The answer does NOT lie in blowing insulation between joists, as it is the joists themselves that are connecting the spaces together, much like a string pulled tight between two coffee cans. Our goal with your soundproofing treatment is actually to help "snip" the string, or disconnect the flooring surface upstairs from the ceiling surface downstairs, and then line the entire assembly with density. Density impedes vibration, much like grasping the prongs of a tuning fork, if vibrations are forced to collapse, sound will die.
The soundproofing treatment for a common floor/ceiling assembly targets "either" a floor underlayment upstairs to help "lift" the floor from the struture, or a "density/disconnection" technique applied to the ceiling down below. Either treatment works well, but we warn all clients new to the art of soundproofing, there is no cure. Even if we deliver a 100% collapse in sound bleed straight through the assembly, noise will still trickle through outlets, light cannisters, plumbing fixtures, ventilation systems, perimeter walls that connect up to down, and a host of other flanking pahts. Do NOT venture forward expecting a "cure"....venture forward expecting more "control" over your environment.
How to Soundproof Your Ceiling
The soundproofing goal with a common ceiling/floor assembly is to disconnect the assembly and line it with more density. This wili force the collapse of the transmitting sound waves, and help sound isolate upstairs from down. The density comes in the form of dB-Bloc or Ceiling Caps, depending on your ceiling setup. The disonnection depends on what kind of ceiling you have before we get started. To combat the bleed of noise through your ceiling, your sound barrier treatment options depend on what your starting point is. Select from the following options or call our help desk at 1-800-638-9355 if yours is not listed:
Remember, the common contact points are your culprit! Joists connecting upstairs to down deliver vibrations back and forth. Soundproofing your floor/ceiling assembly has less to do with blowing insulation between your joists (ignoring the path..think of a string pulled tight between two coffee cans), and has more to do with layering "density" and "disconnection" into your assembly.
A good sound barrier ceiling treatment can deliver up to a 90% reduction in plenum noise, foot noise or noise bleeding into or out of your room through the ceiling. A sound absorption ceiling treatment can restore your room to good quality sound by collapsing your reverberations times down to under 2.0 seconds. Both of these results for soundproofing a ceiling are simulated in our Sound Chamber for your listening pleasure.
As we define in our Academy and review in our Walls section of the Applications Guide, sounds bleeding back and forth through a common structure including a ceiling travel along both airborne and structure borne paths. To combat each, we add density and a disconnected structure to help force the sound waves to collapse inside your ceiling cavity.
The joists in the ceiling are your primary culprit. If they are supporting both your ceiling and serving as the floor joists for the floor upstairs, that direct contact point becomes a conduit for sound transmission traveling in both directions. Your goal structurally is to lower your ceiling and/or raise the floor upstairs to create a disconnect. Then line the disconnected assembly with density to combat airborne noise. The density comes in the form of dB-Bloc featured in our Product Bin.
Soundproofing Finished Ceilings:
For finished ceilings, simply staple a layer of dB-Bloc to your existing ceiling. Then anchor either a set of wooden 1x4 firring strips to your ceiling, or a ISO Clip/Metal Channel system to your ceiling. In either case, be sure to run these strips perpendicular to the direction of your floor joists. Then apply a new layer of drywall to these strips or metal hat channels and finish off your new ceiling. The strips create a dead air gap between the dB-Bloc layer and your new, finished drywall surface.
Soundproofing For Exposed Joist Ceilings:
If your ceiling is unfinished, the joists are exposed and still remain the primary culprit. Follow the same technique. Staple dB-Bloc direct to your joists, then run a set of firring strips or metal hat channels perpendicular to the direction of the joists, and then apply your drywall to the strips. If you're putting a drop-grid ceiling tile system in instead of drywall, staple dB-Bloc to the joists, anchor that weight with the wooden 1x4 firring strips placed perpendicular to the direction of the joists, and then hang your grid. Drop the tiles into place.
Soundproofing For Existing Drop Grid Ceiling System:
If you have an existing ceiling tile system in place, you need to add density to your system to help block the bleed of noise in and out through the ceiling. By definition, your drop grid tile system has already forced the "disconnection" between the floor upstairs and the ceiling down below. What you lack is the density on the grid system...ceilng tlies by themselves are not dense enough to block sound bleed. In turn, we will ship you a corresponding set of Ceiling Caps that are dense, insulation plates that rest atop your existing ceiling tiles. This produces the density you need, and can force the collapse of the transmitting sound wave.
Soundproofing By Replacing Existing Ceiling Tiles:
If you want to replace existing ceiling tiles with more effective tiles, and your goal is to block the noise from bleeding in and out through your ceiling, replace your tiles with the Granite Tiles showcased in our Product Bin. These are tiles lined with dB-Bloc and designed to trigger a drop in sound bleed through the ceiling. All products mentioned here are featured in our Product Bin.
Fiberglass Batting Insulation Myth
Finally, regarding the use of fiberglass insulation, this material contains little density and does not create any disconnection to your ceiling assembly system. Stuffing insulation between your ceiling joists is a good idea for thermal insulation and controlling zone temperatures within your facility, but does little to block noise from bleeding in or out through your ceiling. The material will, however, help absorb energy trapped inside a disconnected ceiling assembly system that has been lined with dB-Bloc. The use of this material is your choice, but do not use it as a substitute for weight or disconnection.
Finally, for new build or remodels, consider more track lighting over recessed cannister lighting to help minimize the number of holes you are cutting into your ceiling.