Soundproof drywall is a high performance engineered soundproofing product with enhanced noise reducing properties to soundproof interior walls.
These special drywall panels are made up of multiple layers of different materials, meant to increase the mass of the wall, thereby reducing the amount of sound penetrating through to another room.
What Materials are in Soundproof Drywall?
The layers that make up soundproofing drywall panels varies depending on the level of performance it was designed for. Most often the are constructed of thick paper facing, gypsum, steel sheet metal, and special mass loaded polymers.
Gypsum is a mineral with a composition of calcium sulfate dihydrate. It is a soft mineral that when mixed with a binder, can be pressed together into hard sheets, then wrapped with thick paper liners to form a sheetrock panel.
The steel sheet metal and mass loaded polymer layers are typically sandwiched in between the layers of gypsum. This construction forms a rigid, and mass loaded drywall panel perfect for soundproofing a wall in a room. Photo credit: EssG
How to Install Soundproof Drywall
Soundproofing drywall can be installed anywhere standard drywall is used. Before you install the drywall, you should stop and consider first installing some quality soundproofing insulation like rockwool insulation.
You can use normal drywall screws to attach the sheetrock to the studs. Use coarse threaded screws when mounting onto wood stud walls. Use fine threaded screws when attaching panels to metal studded walls.
To prevent unwanted sound leakage, you will want to take the extra steps of sealing with soundproof glue. You should seal all electrical cut outs like light switches and power outlets. Then you need to apply the soundproofing glue to all the seams of the drywall.
Optionally, you can go the extra mile and use resilient channels to get the greatest soundproofing results. Resilient channels are extruded metal forms that attach to the studs, and then the soundproof drywall attaches to the channels.
Expected Performance of Soundproof Drywall
The performance of your soundproof sheet rocked room will vary greatly depending on the overall construction of the walls.
According to QuietRock, a manufacturer of engineered drywall systems, their QuietRock 530 product can deliver an STC rating of 52-53 by itself. The 530 product features 2 layers of gypsum sandwiching steel and polymer layers, forming a 5/8″ thick board. See our QuietRock Review.
Some examples of wall contruction and STC ratings:
A wall with 3-5/8 inch steel studs, 24 inch spacings, with QuietRock on both sides acheived an STC of 55 in laboratory tests.
A wall with 6 inch steel studs, 16 inch spacings, with QuietRock on both sides measured at an STC of 53.
For improved STC ratings, a double stud wall construction should be used. For example, an STC of 66 was acheived with double 2×4 wood stud wall, with 9-1/2 inch batt insulation, and soundproof drywall on both sides.
The maximum performance was acheived with double wood studs, 24 inch spacing, 9-1/2 inch batt soundproof insulation, and double layer soundproofing drywall on both sides. This wall is 12-1/2 inches thick and reached an STC of 74 in lab testing.
Remember to always follow the manufacturers instructions and best practices, and you can also achieve top soundproofing results.
Real Life Test of Soundproofing Drywall
Here is a very cool video where a home builder had installed QuietRock drywall in a bedroom that was adjacent a bathroom. He performs the test by turning on a very loud stereo in the bathroom, walks into the bedroom, shuts the door, and then listens. The radio noise has been all but eliminated through the wall. It really proves how effective a properly built soundproofed wall can be in real life.