Typical sounds that travel through the floor and into the ceiling below are footsteps (impact noise), voices, stereos, barking, and even loud appliances. Noise (vibration) can easily transfer down through the floor / ceiling framing. Soundproofing the floor of your condo, studios or apartment can significantly reduce or eliminate this noisy intrusion and make your space more peaceful and quiet for those around you. Before we recommend a system to block the noise, let’s find out what you’re up against.
Soundproofing Problem – Impact Noise: Impact noise, also known as footfall noise, occurs with an actual physical impact on the floor above. Might be a footstep or a chair dragging on the floor. Impact noise can also be from objects being moved or rolled across the floor, or vibrations such as those from a washer or dryer.
The Only Solution is Decoupling, Mass, Absorption and Damping, four of the 4 Elements of Soundproofing.
The first element is decoupling. Keep in mind that sound is nothing more than a vibration. The vibration will travel (conduct) easily if there is a nice solid direct pathway to follow, like the string between two orange juice cans. If we cut the string, however, we “decouple” the pathway, and the sound vibration stops (no conduction).
Air cavities will resonate. Ever “heard the ocean” in a seashell? Ever blow across the top of a bottle and heard the sound? Both sounds are actually the trapped air resonating. A hollow wall will also trap air that will resonate. When the wall is vibrated by sound (from your neighbor), the air in the wall cavity is also vibrated, just like a drum. This air cavity is another means for sound vibration to travel from one side of the wall to the other
A very important element. In this case we simply mean make the walls as heavy as you can. Common cost effective choices for heavy materials include Drywall, Plywood, OSB, and Cement Board.
For sound to conduct through a wall, it has to actually move the wall ever so slightly . A heavy wall is harder to move than a lighter wall. Simple as that. Drywall is one of the lowest cost sources of mass available. Best to use two layers of 5/8″ drywall. It is very important to note that a heavy wall will still vibrate, just not as easily
The last element for soundproofing. If we could reduce the drywall from vibrating in the first place, it would make the jobs of the mass, the insulation and the decoupling easier and much more effective. After all standard drywall is a HUGE surface area that is vibrating.
This solution finally addresses the noise vibration right at its source by applying mass and damping to the underside of the problematic subfloor. Because this method directly addresses the vibration, there will be much less sound available to travel to the joists as well as your walls below..