Double Sheetrock for Soundproofing – (Explained for Beginners)
The availability of soundproofing tips and materials is overwhelming and confusing, and you do not know where to start. With so many options, it’s hard to choose which one really works.
Whether you are planning to do a house remodeling or simply want to enforce effective soundproofing, there is a good chance that you need to add layers to your existing soundproofing drywall.
The science behind soundproofing is inspiring. If you intend to thicken the layers in your walls, doubling the sheetrock is one cost-effective solution in sound deadening.
Let’s see how sheetrock works in soundproofing.
What is Double Layer Drywall Soundproofing?
You are wrong if you think that soundproofing an existing wall using double layers of sheetrock is ineffective. It is actually one of the cheapest ways to add sound-deadening material.
As the phrase implies, double drywall soundproofing means having two layers of standard drywall!
It is pretty intuitive to understand that double walls are more effective in blocking sounds than a single partition.
Damped Green Glue acoustical sealant and double-layer sheetrock acoustic panel will reduce the transfer of sound energy between walls. Adding this sound-deadening compound will help you achieve a solid soundproofing performance.
Pro tip: Always remember to use acoustical caulk to seal the sides of electrical wires, boxes, and receptacles and perimeters on joints, never to leave air pockets as channels of noise.
What is the Purpose of Double drywall?
The purpose of double drywall is to stop sound. Though stopping sound using double drywall alone is near to impossible, it does help in dampening sound.
A sheet of soundproofing drywall serves as a sound barrier to reduce the vibrating effect of sound waves.
Sound is an energy that travels through waves. By installing an object that will block the waves, the patterns of these waves will get distorted once they hit an object, thus, the drywall panel.
And if two drywalls are working with each other, bouncing off the waves through and fro, the sound will weaken once it reaches the room.
Double sheetrock: Is it Worth Soundproofing?
It is like you’re asking if two drywalls are effective in soundproofing. Using two sheetrock is a cost-effective solution in soundproofing.
Sheetrock is often interchanged in usage with drywall. Sheetrock is a name of a brand of drywall and it is used on ceilings and walls.
What is sheetrock made of?
The difference between sheetrock from drywall is the formula built on it for patent purposes. That’s all there is.
Sheetrock drywall is a plasterboard that is made of two paperboards with gypsum in between. Gypsum is the white powdery sulfate mineral that is used on drywall materials but is non-combustible and lightweight.
Benefits of Double Sheetrock for Soundproofing
Adding another layer of soundproof drywall using sheetrock offers enormous benefits in soundproofing. Having two layers of sheetrock reinforced with fiberglass insulation or spray foam and decoupling materials helps prevent sound from passing through by all means.
To sum up, you will achieve the following benefits:
More effective in noise reduction—especially useful when noise is coming from the adjacent room.
Additional mass—for more effective soundproofing, you can add mass-loaded vinyl. But for cost-efficiency purposes, sheetrock double walling will also do the trick. The Green Glue noise-proofing compound will help absorb sound vibration or sound wave movement.
Increases the drywall’s fire resistance—doubling the sheetrock increases the STC rating of the regular drywall panel.
Double sheetrock soundproofing is best when you are converting a room into an entertainment center, theater, voice booth, or recording studio.
With this in mind, you can add sound insulation materials such as the following:
- Acoustic foam
- Soundproof blanket to hang on windows
- Weatherstripping to soundproof window
- Fiberglass insulation for more effective noise reduction
QuietRock vs. Double Drywall
The idea of soundproofing a space is to decrease or weaken sound transmission. That’s why most building wall assemblies have designated sound transmission class (STC) ratings.
QuietRock is an intelligent choice when adding another layer to your room’s existing drywall if you aim to have a quieter room.
QuietRock is a brand of drywall especially designed for reducing sound. It is a type of board that can be used for acoustic treatment in place of generic drywall.
QuietRock makes the difference in space since the material is specially designed and tested for sound transmission.
Single QuietRock drywall does better than double drywall. It also saves you more time in installation.
QuietRock is an excellent choice for soundproofing goals. The sheets are lab and field-tested and come in different layers of STC performance and fire resistance.
Generic gypsum boards usually are fire hazards and combustible. It is the opposite for QuietRock.
So, QuietRock performs better and is an excellent choice over double drywall when you don’t want to compromise on quality.
Decoupling for Enhanced Soundproofing Performance
Decoupling is one crucial element of soundproofing. Other elements are damping, absorption, and mass. While these three have been profoundly immersive in this article, we single out decoupling to emphasize the value of QuietRock drywall.
Decoupling refers to the separation of two layers of drywall. We have two types:
- Decoupled drywalls using no connections
- Decoupled drywalls but insulated
In soundproofing, resilient decoupling mounts are used to thwart the passing of sound through hardwood studs.
| Assembly | STC |
| 2×4 Wood Stud Partition Wall (24” spacing) With 3-1/2” Fiberglass Installed | |
| 1/2-inch layer of drywall on each side (1.6 psf) | 42 |
| 1/2-inch QuietRock 510 panel installed vertically on each side (2.1 psf) | 52 |
| 1/2-inch double layer (1” thickness) drywall on each side (3.2 psf) | 46 |
| 5/8-inch layer of drywall on each side (2.3 psf) | 48 |
| 5/8-inch layer of drywall on each side with resilient channel | 51 |
| 5/8-inch EZ-SNAP QuietRock panel installed on each side (2.6 psf) | 51 |
| 5/8-inch QuietRock 530 panel installed vertically on each side (4.1 psf) | 52 |
| 5/8-inch double layer (1-1/4” thickness) drywall on each side (4.6 psf) | 54 |
| 5/8-inch double layer (1-1/4” thickness) drywall on each side with Green Glue | 59 |
These mounts are also called sound clips. Without them, sound can easily travel from one side of the wall stud to the other drywall. Because sound is being diverted, it will find an air cavity to penetrate. Since there is no air pocket present, soundproofing becomes even more effective.
Pro tip: Be sure to use resilient mounts when decoupling drywalls. The performance of decoupled walls is worse when no decoupling mounts are used, as it will only result in resonance.
Related Questions
Do you have to remove sheetrock from the drywall?
No. Adding a QuietRock panel to the existing drywall makes the soundproofing more efficient because it will add to the STC rating of the old drywall.
Does double insulation help with sound?
Yes. Double drywall means extra mass when two single drywalls are combined. That extra mass means a dense barrier for better sound attenuation.
How thick should drywall be on the ceiling?
The standard thickness recommended for sheetrock panels for ceilings is a one-half-inch gypsum board. But if your purpose is for soundproofing, use QuietRock sheetrock.
To determine the actual thickness you need for your home or building, it is better to seek professional advice since the thickness will depend on many variables—the area of coverage, types of joists, and the materials used in the ceiling.
PRO tip: Get the most soundproofing effect from your QuietRock sheetrock by using the Green Glue compound. It is a damping compound that is important in stopping sound vibration travel between two drywalls.
Conclusion
It is easy to go back to sound 101 to understand how sound travels between walls. Having suitable materials and soundproofing elements on hand will help us build a soundproof room.
Sheetrock, like QuietRock, can increase the STC rating of your wall. And using double sheetrock is an effective soundproofing technique.
But what is extremely powerful is when you use sheetrock of soundproofing grade like QuietRock.
Use this guide the next time you have soundproofing DIYs at home or have room to soundproof for acoustic purposes.