Sound Isolation Solutions For Walls

Decoupling: Decoupling will always provide superior isolation over all other methods or products. The most cost efficient way to decouple your wall drywall is the use of resilient sound clips. Please note that this option will require the demolition of your existing drywall to attach the clips directly to the studs. This is a requirement to avoid something known as the triple leaf effect which, if ignored, will reduce performance of the clips significantly.

When dealing with airborne noise, the STC and OITC ratings are what should be reviewed. The STC rating (rating measuring isolation of mid and high frequency noise) of a GenieClip system on wood studs with double layer drywall installed is STC 61. This STC rating is roughly a 500% gain over a standard wall with single layer drywall on both sides. Reaching an STC rating above 60 in a wall will resolve the majority of airborne noise transfer complaints. The OITC rating for this same assembly will be OITC 44 which is roughly a 300% gain over a standard framed wall. These increases in ratings far exceed any other increase from a single product or method of sound isolation.

Green Glue Compound: Treating the wall with Green Glue Compound will significantly decrease the airborne noise sound transmission between rooms. The STC rating of a wall with Green Glue Compound is bumped from STC 35 to about STC 52. This is considered to be over a 300% increase in sound isolation performance. Adding an additional layer of drywall and Green Glue Compound will bring the STC rating up to STC 56 with the OITC rating hanging around the high 30's.

Mass Loaded Vinyl: Depending on your expected results, mass loaded vinyl might just do the trick for you. With no gain in isolation for low frequencies, mass loaded vinyl will have beyond double the performance of your wall in the mid to high frequency ranges. Installation is simple on walls and with the 1 LB material you will only lose 1/8th of an inch of space. The STC ratings of 1 LB MLV barrier in a wall is STC 44 with no change in OITC over a standard wall which is typically around OITC 30. Swapping the 1 LB material for 2 LB will double the thickness and weight of the material and increase performance to around STC 50 with likely a minimal boost in OITC performance.

Adding A Layer of Drywall: If you want to cut down on high frequency sound transmission and you are not looking for an 'A' for effort, then adding a layer of 5/8" might suit you. We would not consider this option even remotely effective, but adding mass to a wall that is already semi-resilient will provide a noticeable improvement. Little improvement, but noticeable and of course very affordable. To significantly improve isolation with mass alone you will need to double the amount of mass on your wall. If you currently have two layers total between both sides then you will need to add two more layers to either side. If you currently have four layers total between both sides then you will need to add two more layers to both sides and so on.

Sound Board: Sound board used anywhere other than in a floor has as much benefit as adding a single layer of drywall. The only worthy attribute of sound board is that it provides a slight break in connection between the drywall and the framing. The improvement from this break is quickly lost due to the minimal mass of the sound board. So ultimately a layer of sound board will test as well as adding a layer of drywall.

Insulation Alone: Insulation will cut down on airborne noise that passes between the wall stud cavities. It will of course not treat the wall studs in any way so insulation alone should not be considered a solution for your problems. As always, it is still recommended to fill your drum-like wall stud cavities, but beyond that little improvement can be experienced with insulation regardless of type of insulation.

Foam Strips/Integrity Gasket/Noiseproofing Tape/Green Glue Compound On Studs: All these are novel ideas, but in the end they are not nearly capable of dispersing enough energy to isolate a noticeable level of sound. These products are cheap so they are appealing, but your time and money can be spent much wiser on pretty much anything else.

Option 1

• Resilient Sound Clips: We recommend the GenieClip for the highest STC rating possible.
• Furring Hat Channel: This can be purchased online through our site or locally for much cheaper at any drywall distributor in the United States. Channel currently sells for about .40 cents per linear foot depending on the market and constantly fluctuating steel prices.
• Double Layer Drywall: We strongly recommend using double layer drywall on any clip system. The extra cost is minimal overall and the increase in performance is more than double.
• Green Glue Sealant: Clip systems can only perform well if they are sealed well. The wall drywall should be cut back 1/4" from the perimeter walls and caulked using a flexible acoustic caulk. Any other gaps remaining in the wall after texture must be sealed with an acoustic caulk.

Option 2

• Green Glue Compound: The lower performing option of the two, but definitely the less complicated installation.
• New Layer of Drywall: If you have existing drywall then simply overlay with a new layer of 1/2" or 5/8". We recommend 5/8" to improve performance in isolating low frequencies, but either thickness will be fine.
• Acoustic Caulk: Any gaps in the wall and along the perimeter of the room must be sealed to reduce noise transfer and flanking. Sealing around outlet openings, light openings, doors, windows, and HVAC openings is required.

Option 3

• Mass Loaded Vinyl: Some isolation goals are basic and sometimes mass loaded vinyl installation is preferred. One LB barrier is the most commonly purchased, but the 2 LB will give you a noticeable boost over 1 LB. Install the MLV against your studs for the highest performance.
• New Layer of Drywall: MLV is not a finish product so you will need to overlay it with another layer of drywall. You can use either 1/2" or 5/8" for this with little to no difference between the two.
• Acoustic Caulk: Any gaps in the wall and along the perimeter of the room must be sealed to reduce noise transfer and flanking. Sealing around outlet openings, light openings, doors, windows, and HVAC openings is required.

Option 4

• Framing Studs: You can remove the existing drywall and either retrofit your existing standard 2" x 4" wall to a new 2" x 6" staggered stud wall or build a new stud wall in front of the existing wall. Performance of the staggered stud wall rates between Green Glue Compound alone and a resilient sound clip wall alone. Performance of the double stud wall (with 3" gap) is equal to a resilient sound clip wall. The space lost from a staggered stud wall is just slightly more than a resilient sound clip wall, but a double stud wall will lose at least another 6 1/2". If you have the room to sacrifice the space then a double stud wall is not a bad option at all.
• New Layer of Drywall: You will have to remove the drywall to get to the framing so you will now have to replace that drywall. Double layer is recommended, but of course only a single layer is required.
• Green Glue Compound: Staggered stud and double stud walls isolate airborne noise transfer well, but they do not deal with flanking. We still recommend using Green Glue Compound on staggered and double stud walls to reduce flanking from entering the framing above and below the wall. There are no sound tests showing the benefit of Green Glue Compound on a staggered stud or double stud wall. However, sound tests are done in perfect environments where flanking really does not exist. In the real world, flanking is a major problem so it should still be addressed in a specialty framed wall just like any other wall or ceiling.
• Acoustic Caulk: Any gaps in the wall and along the perimeter of the room must be sealed to reduce noise transfer and flanking. Sealing around outlet openings, light openings, doors, windows, and HVAC openings is required.

Possible Additions

• TotalSeal Putty Pads: Walls typically have many more outlets than ceilings do. Be sure to seal your outlets and apply a putty pad to the back of the outlet if you have several outlets. We would consider several outlets as 3 or more single gang outlets in a 12' x 8' area.
• Combining Methods: Combining decoupling with damping and absorption will increase the performance of a decoupled wall significantly. Adding more mass and absorption to a dampened wall will increase the performance of the dampened wall significantly. Adding more mass on top of more mass does not provide a huge boost in performance and adding more absorption on top of more absorption will also be insignificant. Combining methods (decoupling, damping, mass, absorption) is always the best way to efficiently isolate sound.