Double Drywall or QuietRock for Soundproofing?

There are many ways to ensure that soundproofing your home is successful, and one method that I often hear being mentioned is double drywall or QuietRock for soundproofing. So how does it work? And does it have any significant benefit over just using a single drywall?

In this post, I will share the steps on how you can do it, the materials you need, and shed some light on the effectiveness of using such a technique.

Let’s jump right in.

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Double drywall soundproofing is a common method for reducing noise. It’s also called 2-ply drywall or double-stud construction, and it’s used in both residential and commercial projects.

Drywall is a type of wallboard made from gypsum plaster sandwiched between two sheets of paper. It’s a popular building material because it’s lightweight, easy to install, and inexpensive.

Double drywall soundproofing involves installing an extra layer of drywall on either side of the existing wallboard. The extra layers dampen vibrations caused by sound waves passing through the walls and help prevent sound from escaping into other rooms or outdoors through cracks around windows or doors.

You can also use double drywall to create spaces that are acoustically isolated from one another. This can be useful if you want to run cables between rooms without having to drill holes in the walls.

The main benefit of double drywall is its ability to absorb sound waves, making your home quieter and more peaceful.

Next, let’s take a look at some common materials you can use.

Types of Drywall

types of drywalls for soundproofing

Drywall is made out of gypsum sheets coated in paper with tapered edges on long sides for taping and mudding.

Wallboard, gypsum, gypsum board, plasterboard, and Sheetrock – a brand name – are some of the names and brands used to describe it.

For different needs, several thicknesses are available. The denser and greater mass of the materials, the better it does at helping to reduce sound transfer.

There are several varieties of drywall, but Type X is the most typically used for soundproofing. It is a fire-resistant board, and a board of 5/8′′ thickness can withstand a fire for an hour, making it the greatest drywall for noise reduction.

Green Board is a gypsum board that resists moisture. The green covering is more water resistant. Although it is not waterproof, it is commonly used as a backing for tiles in bathrooms, kitchens, and laundry rooms.

Blue Board, which is more resistant to water and mold than Green Board, is commonly used for plaster finishes. It’s designed for plaster finishes and has special absorption capabilities; it’s not designed for tape, mud, or paint.

Paperless Gypsum is covered with fiberglass rather than paper and is far more resistant to moisture, mold, and mildew. Because the fiberglass coating isn’t completely smooth, a slick application of joint compound is required to provide a smooth paint surface. In addition, the boards are more durable than paper-coated gypsum.

Purple covered gypsum panels look like standard sheeting but are more resistant to moisture and mildew. It’s perfect for basements or bathrooms with a lot of water.

And finally, you may also find soundproof drywall sheets such as QuietRock.

A layer of sound-absorbing substance is placed between two layers of gypsum in such drywall sheets where it has a higher density than equivalent thicknesses and hence blocks more sound. They are frequently used in media rooms or other areas where noise intrusion or interruption is a concern.

What is Sheetrock?

The main thing to know about Sheetrock is that it is only a drywall brand name. Both terms are interchangeable and refer to the same thing.

Sheetrock is made by the United States Gypsum Corporation (USG), which is also the country’s leading distributor of wallboard. Sheetrock has been manufactured by the company since 1901. During the Great Depression, USG was profitable every year, and after nearly going bankrupt in 2001, it returned to profitability in 2013.

It’s no surprise that because USG has been the main drywall distributor for over a century, its name has been synonymous with the product.

What is QuietRock?

A viscoelastic polymer sandwiched between two gypsum layers makes up QuietRock, a sound-dampening drywall product, and probably one of the best in the market.

The mass of the gypsum blocks soundwaves, while the viscoelastic substance dampens the oscillations of the waves.

When compared to ordinary drywall sheets, the sheet will minimize sound transmission in or out of a room by between 15 and 20 STC points.

The sheets come in thicknesses of 1/2 inch, 5/8 inch, and 1-3/8 inch, and in sizes of 4’x8′, 9′, or 10 feet.

It can be scored and snapped like conventional sheets, and the lengths are tapered for taping and mudding.

The 5/8″ 48 sheet weighs 83.2 pounds (2.6 pounds per square foot).

Building materials like drywall and QuietRock can sometimes have fluctuating prices, so check with vendors such as Lowe’s for the most up-to-date information.

Types of QuietRock

Right now, there are 6 different models of QuietRock that are available. Each has its own unique characteristics and can be used in many different situations. The one that I feel is most suitable for creating a soundproof drywall is the EZ-SNAP and QuietRock 530 due to a great balance between price and performance.

You may purchase them at Lowe’s.

EZ-SNAP: the first high-performance sound-dampening gypsum panel that scores and snaps just like other gypsum panels. With no paper or metal in the core of the panel, the proprietary EZ-SNAP technology achieves excellent STC ratings. QuietRock EZ-SNAP combines superior acoustic performance with improved workability, allowing for faster installation. (factsheet)

EZ-SNAP Mold Resistant: high-performance sound dampening gypsum panel for your individual design goals. Mold-resistant paper and core can help to create a healthier indoor environment. QuietRock EZ-SNAP Mold Resistant is easier to install than other acoustical drywall brands because to EZ-SNAP technology. (factsheet)

QuietRock 510: 1/2″ sound-dampening gypsum panel that is suited for use in residential and remodeling projects. No special tools are required to install and finish like ordinary gypsum panels. (factsheet)

QuietRock 530: high-performance sound-dampening gypsum panel with excellent noise reduction and impact resistance. This ‘superpanel’ is UL-certified for fire resistance, STC, shear resistance, and impact resistance. (factsheet)

QuietRock 530-RF: high-performance sound dampening gypsum panel with excellent noise reduction, radio frequency shielding, and impact resistance. This UL fire-rated, STC-rated, shear-rated, and impact-resistant “super-panel” (factsheet)

QuietRock 545: A multi-layer gypsum panel designed to give maximum sound absorption across a wide frequency range. Suited for projects requiring high STC performance at low frequencies and may be used in nearly any application. Commercial theaters, studios, and sound rooms should use QuietRock 545. (factsheet)

Benefits of double drywall: Does double drywall reduce sound?

Double drywall is two layers of drywall that are installed on top of each other, creating an air gap between them. This means that there is less sound transmission through the walls, floors, and ceilings of your home, so you won’t have to worry about noise from inside or outside disturbing your sleep.

You can use any type of drywall on the second layer, however it is best to use sound proofing drywall.

Sound proofing drywall is more expensive than standard drywall, and you can find it at many home improvement stores.

Double drywall also makes it easier for people in older homes to maintain their homes’ energy efficiency because it creates a better thermal break between the outside and inside of the house during winter months when heat is being lost through windows and doors.

The most important thing to understand about double drywall is that it’s designed primarily to reduce the sound of voices, music, and footsteps. It’s not as effective at reducing low frequency sounds such as bass sounds from music or from appliances or ventilation equipment. You will still hear your neighbor’s alarm clock or television set through a double drywalled wall.

There are some situations in which double drywall can be effective against low frequency noise if there is some control over the environment where the noise originates.

For example, if you have an adjoining room that shares a wall with your home theater system (or any other source of loud noise) and you want to prevent that noise from getting into the adjacent room then double drywalling could be an effective solution.

If there are no windows in the adjacent room then it may also be possible to use high-density fiberglass insulation between the two layers of drywall so long as this installation does not interfere with any joists or beams that run between them.

How to make your double drywall more effective?

To get the most soundproofing benefits of a double wall, it’s best to go with a staggered stud framing system. This is where your studs are offset from each other by 16 inches.

In some cases, this may mean that you’ll have a stud directly behind an outlet or switch, which means you’ll have to run cable through inside the stud rather than on its face.

But don’t fret—this is actually quite easy: simply find the hole at the top of your box and snake the wire through.

Because staggered stud framing leaves more room for insulation and sound absorption between walls, it’s highly recommended when building a double wall for soundproofing purposes. It will also provide better fire resistance than standard 2×4 framing systems.

If you are building a new house, then the double wall should be built into the framing, not added during construction as an afterthought. The second layer of drywall should be staggered from the first layer, and this is easier to do when you start with a staggered stud framing system.

This is because it is more effective with a staggered stud framing system. You will want to use two layers of 5/8-inch drywall separated by resilient clips that isolate each of the layers from each other.

How to improve the acoustic performance of a room?

Absorption, damping, decoupling, and increasing mass are the four factors of soundproofing that must be addressed to make a room quieter.

Creating a drywall with QuietRock and Green Glue adds mass and dampens airborne noise. Take note that mechanical (impact) or surrounding noise are not addressed by this soundproofing technique.

Sound can get through your drywall soundproofing efforts through outlets, switch boxes, light fixtures, and vents. Unless dampened, frequency vibrations can ricochet from room to room. Putty pads are a viscoelastic substance that can be wrapped around electrical boxes and vents to reduce noise.

Another technique to reduce vibration is to use acoustic caulking. Between the drywall and the floor, ceiling, and surrounding walls, there should be a gap. Caulking the spaces helps to keep sound from moving around.

By decoupling the wall layers with resilient clips and channels, you can further reduce the impact of vibrational sound waves. The STC can be improved by 12 to 15 points just by doing so.

Drywall vs QuietRock

The choice of whether to use a regular drywall or QuietRock really comes down to 3 key factors: use, cost, and installation.

To me, using QuietRock panels is without a doubt the best solution if you want better soundproofing.

They have a higher STC rating than regular drywall materials. In fact, a single sheet of QuietRock is said to offer the same sound dampening ability as eight layers of normal drywall.

When it comes to space, QuietRock will help you save on it since you will use lesser pieces to achieve the same or superior effect.

Installation is simple. Using numerous layers of drywall or other methods such as Green Glue might be difficult.

The cost is probably the only disadvantage in this case, as 1 sheet of QuietRock can potentially get you up to 7 or 8 pieces of drywall.

I still think that the benefits far outweigh the cons though.

How to install QuietRock?

STC rating of various assemblies

Going for double drywalling or using a soundproof drywall sheet like QuietRock are both going to be quite effective for blocking out noise, and you can check out the table below for more information about their STC ratings.

AssemblySTC rating
1/2-inch layer 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 drywall on each side (2.3 psf)48
5/8-inch layer drywall on each side with resilient channel51
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 Glue59

In conclusion: Double Drywall or QuietRock for Soundproofing?

Both methods are excellent ways to soundproof a room, so it really comes down to deciding how you want it done and at what cost.

If you want to improve the sound quality of a room, especially if you have a chance to do so for a new home, you should really consider either double drywalling or investing in a high-quality soundproof drywall like QuietRock.

What to read next:

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Bryant

Bryant Littlewood is the Chief Editor behind SoundproofingHacks. He shares all the lessons he has learned in turning his home and office into quiet sanctuaries across the blog posts here. Bryant is also a part-time audiophile, and some of the posts here will reflect that passion of his too. Connect with him on LinkedIn or read more on the about page.