Soundproof and drywall is not something that you typically find together in a sentence unless asking how to do so. Have you ever owned an apartment and could hear your neighbor’s tv blaring? That is because you have drywall issues.
How soundproof is drywall as a material for home projects? Drywall alone is not very sound resistant but with the right panels, caulking, and insulation, sound absorption can be enhanced.
The goal is to break up the transmission of sound waves within the walls and absorb them like a sponge. We’ll show you the right recipe for sound control. And though it may cost more upfront, it will be worth it in the long run.
First, let’s look at what drywall is made out of to determine how to make it more resistant against soundwaves. Drywall is made of cheap materials to cut costs and is made out of gypsum plaster sandwiched in between paper, which is why you will also hear it referred to as plasterboard. Did you know drywall goes by many names?[Source]
- Gypsum board
- Buster Board
- Custard Board
- Gypsum Panel
Drywall comes in three different thicknesses.
- 5/8th inch – The heaviest and thickest slab of drywall. Best for sound control.
- 3/8th inch – The happy medium of drywall, good for covering existing walls
- 1/4th inch – The thinnest of drywall, used more for curved or flexible projects
It is a popular choice as it is easy to cut, shape, and install, even for less experienced builders. There is your typical drywall or gypsum or reinforced “soundproof” drywall.
How to Determine Which Products to Use
There is a rating scale for sound transmission called the sound transmission class. This chart will help you determine which building materials used in a wall or other divider can block out the most soundwaves. Each rating scores how much sound may typically travel through certain materials, the higher the number, the better the sound control.
For instance, if you were using 25 gauge metal studs, the studs are 16 inches apart, with 5/8ths thick drywall, your rating would calculate out to about 42.
To find an STC Rating there are a few factors taken into consideration. This would be:
- Sound frequency
- STC Contour adjustment
- Transmission loss
It is all determined by the way sound travels through different materials.
The Drywall Soundproofing Sandwich
The proper installation techniques when initially installing drywall can make a big difference in sound control. If drywall is made like a sandwich of materials, think of it as, the thicker the sandwich the more filling, and the better the sandwich. Drywall soundproofing sandwich recipe comes down to these simple ingredients:
- Plaster (optional)
1. The Drywall
Choosing a tried and true soundproof drywall material even if it costs a few extra bucks, it will be worth it in the long run. Quietrock and Soundbreak are two of the most popular acoustically enhanced brands recommended by construction professionals. and can typically be found at your local hardware retailer.
The caulking or silicone is the filling in your drywall sandwich. The filling between your two layers of drywall pieces helps create a sound absorption area. Placing the silicone caulk on studs and around screws will also help absorb sound. While you can use regular caulking for a cheaper option, the more expensive Greenglue is the way to go.
The great thing about this Greenglue is that it is made to be an acoustic sealant. Which means it will help break up the sound waves as they travel through walls.
There are a couple of different options for purchasing the green glue depending on the size of your project.
Tubes: Easy application with squeeze tubes and a pointed tip to get into cracks and crevices easier.
Bucket: The Bucket would make more sense to use for big projects that require a lot of caulk in between boards, sealing screws, bolts, holes and more.
3. The Insulation
Insulation is another way to absorb sound waves and stop them from traveling through your space. If there is no insulation the sound waves will travel through the wall and bounce around in the open space. There are four different types of insulation to consider.
- Fiberglass – Made up of recycled, compacted glass and other materials, fiberglass is naturally sound absorbent which is why you will often find this in recording studios.
- Wool – Made from the fibers of sheep’s wool, this type of insulation is naturally warm and is good for retaining heat as well as absorbing sound.
- Cellulose – Made from plant fibers combined with flame retardant chemicals. It helps hold in heat and absorb sound.
- Mineral – Made from molten glass or stone and turned into a fibrous material used for superb and very dense insulation
The type of stud used in your construction can also make a difference in sound control for drywall. The studs create the main framing for your walls and are where the planks of drywall will attach. The typical choice is between metal and wood studs. To help locate where they are located, use a stud-finder, otherwise, they are typically 16 to 24 inches apart from each other in the framework.
Metal studs and wooden studs can affect sound absorption differently. A wooden stud has an STC of 35 alone without additives, and a standard metal stud alone has an STC of 44, and since the STC rates sound transmission the higher a score you start with the better. When adding caulk and plasterboard your score and sound absorption will only increase.
Plaster, when compared to the materials of drywall, is much denser and would block the transmission of soundwaves better, but plaster does not have the same thermal capabilities as drywall. However, combining these two materials together could make a powerful barrier. An option would be to cover the drywall with a layer of plaster.
The Drywall Formula Breakdown In Simple Terms
The simple execution of the components of the layering of drywall with added operators, in order to block out soundwaves in the best possible way.
Wear Goggles, a dust mask, and gloves to protect your skin and lungs.
Layer 1: Insulate Walls with Chosen Insulation Type
Layer 2: Apply Silicone/caulk to Metal or Wooden studs
Layer 3: Apply the first Layer of Drywall
Layer 4: Let Dry for 24 hours
Layer 5: Apply a gracious amount of Silicone Caulk to Back of Next Drywall Piece and attach to the first layer of Drywall
Layer 6: Apply Layer of Plaster to the outside of drywall (optional)
Don’t forget to use drywall nails to hang your drywall and tape the joints and openings in between and after hangings. The more seamless, the more soundproof. [Source]
Drywall Hacks for Soundproofing Existing Walls
Let’s say your space is already made with drywall, is there a way to help soundproof the space without tearing down existing walls and starting over from scratch? Yes!
Option 1: Seal any cracks, gaps, or holes in the wall, baseboards, and around windows, This will also help insulate your house.
Option 2: Interior Design. Fill a room with fabric couches, rugs, wall hangings and more to break up and absorb soundwaves
Option 3: Install sound-absorbing acoustic panels. These can be purchased for a reasonable price and hung on the wall in patterns to make an eye-catching design and absorb soundwaves. For example, a music studio will often have acoustic panels on the walls. Some of these panels are now made to be more decorative.
All of these elements together can help to create a soundproof room, a space optimal for quiet and relaxation. It helps to keep in mind if air can flow through, so can the soundwaves, a tight, seamless finish will aid in the reduction of sound travel. The ability to control the redirection and absorption of soundwaves is the key element in creating a quieter space.