What Is Soundproof Drywall? (and Does it Really Work?)

Soundproof drywall sure is one of the cheapest and effective options for blocking sound. But what exactly is a soundproof drywall and how does it soundproof your room?

Essentially, soundproof drywall consists of multiple layers of varying materials used to reduce or eliminate noise from a room. It restricts the sound waves from penetrating the wall by increasing its mass.

Let’s dive into the details of what a soundproof drywall is to better understand how it works and will it be suitable for you. But before that, an understanding of drywall is crucial.

What is Soundproof Drywall? 

Drywall is a construction material that is applied in the form of large sturdy sheets on the interior walls of dwellings for insulation and soundproofing. It can also help to create arches, eaves, and other architectural design features. Some other names for drywall are wall-board, gypsum panels, sheet-rock, buster, or custard boards.   

Drywall comes in various sizes and thicknesses, but is typically around 1.2 meters wide and 2.4 meters long. You will need special drywall nails and screws to attach/apply them to the wall. They hold the heavy sheets firmly in their places and the nails prevent gypsum from shattering when it’s penetrated.

In other words, drywall is a modern-day, easy-to-apply alternative to the old hand-applied wall plasters of the in-home construction world. You can apply it directly to the wall without any plaster or mortar. Gypsum, asbestos-cement board, or wood pulp are some commonly used materials for drywalls.

Gypsum drywalls are more common and also act as a fire-resistant in crystalline form. They have impeccable acoustic (sound-suppressing/absorbing) capabilities, making them a great choice for those looking to soundproof their rooms or studio. The installation is a simple three-step process including cutting, hanging and finishing the drywall.   

How Does a Soundproof Drywall Work? 

Soundproof drywalls work similar to how drywalls work. The only difference is their thickness and the quality of materials used. To completely understand how soundproof drywalls block out sound, it’s crucial that you know the materials utilized and their composition. 

Composition of Soundproof Drywall

Calcium sulfate or Gypsum is the core component of a traditional drywall panel. You can design the panel according to the level of performance you require. You can play with the layers, framing adaptations, and concentration and combination of materials used.

Gypsum is a soft mineral that, if mixed with a binder, can be pressed into hard sheets. The gypsum will take the form of a sheetrock panel when sandwiched between layers of thick paper liners. Mass-loaded gypsum can inhibit low, mid, and high frequencies of sound. But gypsum alone is not enough to block sound out. 

How Soundproof Drywall Works? 

Now that you’re well aware of the materials of a soundproof drywall. it’s time to learn how the work together to provide us soundproofing.

To enhance the soundproofing capabilities of a drywall, viscoelastic, ceramics, and another inner layer of gypsum replace the solid gypsum core. Special mass-loaded polymers and steel sheet metal layers are also sometimes interjected in between layers of gypsum to make them more resilient.

The combination creates a strong barrier against the passage of sound waves through the drywall panels and then the walls. They are loaded with abundant mass to absorb or “sip in” sound frequencies from both ends of the spectrum.

Does Soundproof Drywall Really Work? 

Soundproof drywalls work great. The motion (kinetic) energy of sound waves creates vibrations in the medium (air) and in everything it comes into contact with (unless it’s an absorptive surface that will wear out the vibrations). Gypsum drywall panels are typically around 5/8 inches in thickness and this thickness helps them reduce such vibrations.

The value generated from the installation of soundproof drywall outweighs the cost of investment. But to know how well these walls really work, let’s talk a bit about what ‘STC’ is.

Sound Transmission Class or STC is a method defined by the American Society for Testing and Materials (ASTM) to gauge sound transmission loss through a wall. The higher your STC ratings are, the greater the sound attenuation of the sound barrier. Usually, STC points should be 50 or above to block sound from coming in or going out completely.

That said, soundproofing drywall has an STC rating around 50-55, which is good enough to do the job.

What’s the Difference Between Soundproofing Drywall and Standard Drywall? 

You must be wondering if a standard and soundproofing drywall work on the same principles. And how and to what extent would one be better than the other.

Let’s do a little comparison to find out:

  • A soundproofing drywall can outdo a standard assembly by almost 5 STC points (provided all other design elements are the same). This difference is quite a notable reduction in sound transmission. With soundproofing drywalls, the thicker, the better!
  • A soundproof drywall is more expensive. Increased installation time, labor, and material costs utilized for the wide and heavy panels contribute to the additional costs. Moreover, soundproof drywall is thick and takes a considerable portion of the overall width of the wall or the ceiling.
    The prices can vary from distributors to brands. But you can expect a 4 to 14 times increase from the cost of a standard 5/8” or ½” Type X drywall.
  • Noise dampening and increase in the sound quality of the room is another plus for soundproof drywalls. Resilient layers, decoupling clips to reduce reverberations and absorptive technology placed between framing and building structure help to reduce clutter from the environment.

FAQs About Soundproof Drywall

By now, you must have a pretty good idea of soundproof dry walls. But, if you have any lingering queries, our FAQ section is sure to answer them, as well.

How Thick is Soundproof Drywall? 

A good performing soundproof drywall is somewhere around ½ – ¼ inches in thickness. You can also layer them one above the other to increase their soundproofing capacity. For instance, you can improve the soundproofing by 15 to 20 points on STC rating if you pile four drywall sheets together.  

What is the Ideal Air Gap Between Soundproof Drywall sheets? 

As a rule of thumb, you can keep at least 1/8 inch of space between drywall sheets for optimal sound performance. But that can vary upon various factors, since there is no hard and fast rule regarding gaps. 

What’s Better: a 5/8” Drywall or a 1/2″ Drywall? 

If you want sound dampening and complete blocking of sound then the heavier 5/8” drywall is probably your best option. But if you wish to just reduce noise and back-chatter from a room, a ½” drywall is better.
So, essentially, the answer lies in what you wish to achieve with the drywall installation. 

What Are the Benefits of Drywall? 

Other than excellent soundproofing, the drywalls also act as a weather barrier. They are thin and take up no extra space from the room. They provide an additional layer that can retain the temperature and sound within a room.  
Drywalls are also fire resistant due to the use of gypsum, which prevents fire from spreading. They’re quite easy to install, remove, or cut. The best part? You can layer drywalls one above the other to multiply their properties.

How Much Do Soundproof Drywall Costs? 

A single sheet of soundproofing drywall can cost you around $40. It sure is an investment as regular drywall will cost an estimated $10 per sheet. QuietRock is currently selling ½” thick 4×8 foot panels for $54.  
Whereas a conventional ½” thick drywall sheet is around $8. The extra expense is worth the investment if you take sound and/or insulation seriously.

Soundproof drywalls have an STC rating of 50-55 which means if sound transmission is something that concerns you, these drywalls might be well worth the investment. However, soundproofing is not your main concern, drywalls are a cheaper alternative.