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How To Soundproof a Room

By March 30, 2012June 24th, 2012No Comments

Soundproofing a room means that we want sound energy that is created in the room to stay in the room and we want sound energy that is generated from outside the room to stay outside our room where it belongs. In order to soundproof effectively, we must address the floors, ceilings, and walls.

Sound Proofing Sealing Process

First, we must seal all openings in the room, no matter how small they are. Openings around light fixtures, electrical outlets, door edges, moldings and window trims. Use a sealer that is silicon based and will seep into the crack or opening and form a complete seal with all edge surfaces involved. Apply the sealer during the warmer temperatures and let it dry thoroughly. Return and reapply to any areas that have recessed during the drying process.

Walls First

Wall thickness is our friend when it comes to soundproofing using our walls. It does not have to be solid, but as a general rule the thicker the better, up to a point of diminishing returns. It depends on how much sound energy is generated in the room we have to keep in the room and how much sound energy is generated from outside the room that we have to block out. It is also about the way we arrange the materials in the wall. Now we are in the area of vibrational acoustics where we have to control the vibrations from one layer of the wall to another layer of the wall. An example would be a 1/2″ piece of plywood with a vibration damping material applied to its backside and then attached to a 1″ piece of multiple density fiber board. This arrangement provides three different materials for vibrations to have to go through and by doing this they lose their intensity or energy. Remember, vibrations produce sound. Do we need more layers to our wall? It all depends on usage and sound pressure levels. Careful sound pressure measurements are a must both inside and outside the chosen room over different time periods and different usage loads, and give one a starting point for material selection and wall thickness.

Don’t Forget the Ceiling

Ceiling structure for soundproofing is similar in design and composition to our wall technology. One particular soundproofing method used is to decouple the ceiling from the rest of the structure by building another “ceiling” and then decoupling or in common language separating the new soundproofing ceiling from the existing ceiling with isolation clips and airspace. Yes, airspace is another material that we can use to reduce vibrations with. If we decouple the new soundproof ceiling from the existing ceiling and leave an air space between the new and old, we have effectively created an isolation barrier technology and a low frequency diaphragmatic absorber which also absorbs bass energy.

Floors and Ceiling

Our floors are just like our ceiling and we must decouple the new soundproofing structure from the existing floor. We float the new floor over the existing floor and use isolation pads to place the new structure on. The rigidity and construction of the floor system can also contain a calculated air space which can absorb internal bass energy. Any decorative inside the room treatment can be added, and thickness is our friend most of the time when it comes to keeping sounds inside, in and sounds outside, out.

Not Easy Or Cheap

Soundproofing a room is not easy and to do it well is not cheap either. One must first determine how much a noise issue one has and then what is our budget available to deal with this issue. Most of the time, the noise problem can not be resolved with the existing budget and one has to re think the amount of solution versus available dollars and make it go as far as it can and accomplish as much of the noise objective we can. One can do it in steps over time to achieve the desired results.


I am a structural engineer as well as a master furniture maker. I design cabinets for low frequency, activated carbon absorbers. Connect with me on Google+

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