If your neighbor thinks that he’s Pavarotti, but he sounds more like a cat in a fight, and you know more about your neighbor’s private life than you care to know, it may be time to consider soundproofing your walls. There are so many different options on the market, such as drywall, but it can become confusing on which option is best to use.
5/8″ thick QuietRock or double type X drywall are two of the best options but should be considered with the entire soundproofing composition. The best drywall for soundproofing is dependent on what kind of wall you have, what insulating material you use, and what soundproofing levels you require.
Check out the best insulation materials for soundproofing.
To understand which drywall best suits your needs, let’s first explore the basics of the soundproofing process. Read on.
How Does Soundproofing Work?
Sound travels at 343 m/s (1,230 km/h; 767 mph) through the air as waves that transfer the energy from its source such as a stereo speaker to its surrounding area.
Unlike light waves with shorter wavelengths, long-wave sounds are tricky to avoid because they can bend (diffract) and travel through the smallest openings and still reach your hearing. Materials such as metal are superconductors of sound, and sound waves travel through metal at a whopping 21,460 km/h (13,330 mph).
Unlike light, which can only pass through specific solid materials, sound can travel most solid materials and emerge as much the same.
These sound waves are vibrating air particles that make your eardrum vibrate when the waves reach your hearing. We perceive this vibration as sound, and the larger the vibration, the louder we will perceive the sound.
What Is STC?
Sound Transmission Class or STC is a rating given to how well or poorly sound waves travel through structural surfaces such as walls or ceilings. The range is at the standard decibel level of 125-4000Hz of human voices, and Most internal walls have an STC average of 40, while hotels and higher-level STC partitions start at around 60 STC.
| Level of Sound | STC |
| Speech can be understood | 25 |
| Loud speech can be understood | 30 |
| Loud speech heard but not understood | 35 |
| Loud speech heard as a murmur | 40 |
| Loud speech not audible, but heard | 45 |
| Loud noises heard faintly | 50 |
| Most noise won’t travel to neighbors | 60+ |
You can lessen the transfer rate of sound by providing greater mass density, placing of air gaps, or sound-absorbing materials.
Type X Drywall
There are various drywall types, but the Type X drywall is the most commonly used for soundproofing. It is a fire-resistant board, and a board of 5/8″ thickness can resist fire for an hour, which concurrently makes it the best drywall to reduce noise.
There is soundproof drywall enhanced for soundproofing, but the STC rating is negligibly higher than a double layer of type x drywall.
The STC Score of Drywall X 5/8″ Thickness
In the same wall assembly of the QuietRock, a double type X 5/8″ drywall with 3-1/2″ of insulation, green glue between the drywall layers, and steel studs on a wood stud wall brings your STC up to 58 with 2 hrs fire resistance.
QuietRock on a single stud wall has an STC rating of 56, decoupled with a double-thick stud wall; the STC rises to 75. Doubling the 545 produces an STC of 80.
What Kind of Drywall Should I Use for Soundproofing?
Drywall is a blanket term that covers, gypsum board, sheetrock, buster board, and plasterboard. It is made up of calcium sulfate dihydrate (gypsum), which may have additives and pressed between two thick sheets of paper. Manufacturers may mix plaster with a variety of fibers, plastics, and foaming agents and additives.
The two main types of drywall commonly used in soundproofing are your regular type X drywall and your soundproof drywalls such as QuietRock drywall. Soundproof drywalls generally use an inner layer of gypsum, viscoelastic, and ceramics to up their STC.
Some of the most popular soundproof drywalls are:
- QuietRock
- CertainTeed’s SilentFX
- National Gypsum’s SoundBreak.
The QuietRock products hold a higher STC rating, but like X type drywall, they need to be measured along with internal insulation, whisper clips, and hat channels. QuietRock uses a three-layer design with viscoelastic polymers that dissipate sound waves optimally.
Best Types of QuietRock Drywall for Soundproofing
There are various types of QuietRock for soundproofing your walls and include:
- EZ-SNAP ($60-$65) – Available in 5/8″ thick 4×8′, 9, or 10″ sheets that score and snap with ease. Because they attach directly to the joists, they take up less space than standard drywall. STC Rating:48-60 (depending on wall construction)
- EZ-SNAP Mold Resistant – It has a mold-resistant covering but has similar soundproofing capabilities as the EZ-SNAP. It is a perfect alternative for damp environments like bathrooms and kitchens. STC Rating: 48-60 (depending on wall construction)
- QuietRock 510 ($105-$110) – This panel is a less expensive thinner option (1/2″ thick 4×8′, 9, 10′, and 12′ gypsum panels), which is great for placing over existing drywall to improve soundproofing. STC Rating: 47-52 (depending on wall construction)
- QuietRock 530 ($105-$110) – A heavier and denser panel available in panels of 5/8″ in4×8′, 9′, 10′ and 12′ sizes. STC Rating: 52-74 (depending on wall construction)
The Best Types of Drywall for Soundproofing
- QuietRock 530 RF – This drywall is similar to the 530 but made to tune out radio frequencies for information-sensitive areas or hospitals.
- QuietRock 545 – This drywall is an 11 layer board made for soundproof studios, theatres, or sound rooms. They are heavy and thick (1-3/8″ thick 4×8′)
Which Is Better: QuietRock vs. Drywall
Obviously, the Quietrock has greater STC capabilities and has the benefit of taking up less space than a double drywall type X (There is quite a price difference for the QuietRock and Drywall, however. Drywall type X 5/8″ regular only costs about $12.
For a 10ft by 10ft room, the costs for a double 5/8″ drywall with green glue would be $487.50. For the same dimensions, EZ-SNAP or QuietRock 530 would be between $600 and $1,100.00
Drywall being double-layered also is a bit more labor-intensive, if that is an essential factor to you.
How Does Drywall Reduce Sound Transfer?
Absorption
Absorption of sound can be achieved using a variety of materials between your drywalls to increase the STC. Sound absorbing materials can be added between your drywalls to soak up sound vibrations such as fiberglass, rubber, viscoelastic foam, and mass loaded vinyl (MLV).
Dampening
Your Barriers, such as drywall, can be turned into the dead panels necessary to cancel sound waves’ vibration. Usually, this would be placing a dampening compound between two layers of drywall, such as Green Glue, which provides a rubber layer that prevents vibration transfer. By adding fiberglass insulation in the cavity in steel stud partitions, you can up your STC by almost 10 points.
Decoupling
The trick nature of soundwaves means they pass quickly through one surface to the other. Decoupling is the process of separating the drywall attachments from the studs and so breaking the direct pathway of sound. Building a staggered stud wall decouples the conduction of sound vibration by forming a break in the rigid connections.
Mass
Mass is essential when it comes to reducing the vibration carried by sound waves. For sound to move through a wall, it has to make the wall vibrate slightly, and the heavier the wall, the less vibration it will carry. Drywall is one of the lowest cost alternatives to provide mass, particularly a double layer of 5/8″ drywall.
Other Factors to Remember
- Vents, heating pipes, light fixtures, and switch boxes can conduct sound frequency vibrations from one room to another. Putty pads can help reduce this transfer of sound.
- There should be a gap between your drywall and the adjacent walls and ceiling. You should fill these areas with acoustic caulking to reduce sound transfer.
- Resilient clips and channels can decrease sound by 12-15 STC points.
Conclusion
QuietRock and Drywall both perform well when you are looking to soundproof your home. Drywall is by far the most cost-effective if you are aiming to cut out general sounds in the average ratios. QuietRock saves you labor and space but not necessarily your pocket. Either way, we wish you silent nights and sweet dreams.
Check out my recommended products for soundproofing.