Frustrated with my neighbors’ noisy dog barking all hours of the day and night, I needed a way to get some peace and quiet at home. But I also didn’t want to spend a fortune on soundproofing. I’d heard that cork was a good soundproofing material, but I had never used it before, so I went searching for information.
Is cork good for soundproofing? It turns out cork is an excellent natural soundproofing material. It is one of the few sustainable and recyclable soundproofing materials that won’t break your bank account. Cork is such an efficient sound dampener that it is often used in recording studios and theaters.
That all sounded too good to be true, but I admit, I was intrigued. I dug deeper and found a lot more information on cork as soundproofing material, and I was more excited than before. Let me share what I found.[toc]
What Is Cork?
During my research, I was surprised to learn that cork is more than 50% air. Of course, I already knew that you could use air as insulation to prevent heat loss, but I hadn’t realized air was a good sound dampener, too.
Cork is a buoyant, impermeable, cellular material. It is made up of a honeycomb design of air-sealed cells made of the bark of the cork oak. The cells each absorb the vibrations of sound, preventing those sounds from passing through to the other side.
Because cork oak trees are not cut down in order to make cork, the cork industry is considered sustainable and environmentally friendly. That made me feel much better about considering cork for my soundproofing needs.
A nice bonus to cork as a soundproofing material is that it’s also a natural fire retardant. Hey, if I can kill two birds with one stone, I’m going to do it. You have to love the efficiency of a two-in-one product.
Cork comes in panels, underlayment, planks, and tiles to meet your soundproofing needs. It can be used in walls and floors. And since it’s lightweight, it’s super easy to install.
But I’m getting ahead of myself. I’ll cover more on all that later.
Does Cork Reduce Noise?
Yes, cork is an excellent noise-reducer. It doesn’t take much to get effective soundproofing out of cork. From what I found, 3/32” (just three millimeters) of cork can block up to 10 decibels of sound.
It’s time for a quick science lesson. Sound moves in waves. In order for us to hear those sounds, all of the waves need to remain intact. When sound waves are disrupted, sounds are muffled or completely eliminated.
Cork works by breaking down sound waves within the cell walls and diffusing them.
Cork is great for walls as it absorbs about 40% of the sound in the frequency range produced by the human voice. Used on walls or floors cork will deaden vibration and sound transfer by absorbing the noise, not reflecting it like a hard solid surface. Cork will effectively stop echo noise too.
Cork Acoustic Properties
Cork comes from the bark of the evergreen cork oak. 80% of the world’s cork comes from the western Mediterranean area. Once a tree reaches 10” in diameter, it is harvested. Every 9 – 14 years after that, it will be harvested again, making it a sustainable product.
Cork is a great insulator. It ranks second only to felted wool as a thermal insulator, the stuff Mongolian Yurts are made of, and second to solid rubber as an acoustic insulator. It is the cell structure of the cork that gives it its acoustic properties.
- Sound Absorption
The honeycomb-like cell structure of cork and the airspaces trapped in the structure make it an effective soundproofing material. A cubic centimeter, approximately 3/8” cubed, contains about 40 million cells. When sound tries to pass through it, it is trapped and absorbed. A thin layer (3/32”) will absorb 10dB of sound.
- Noise Reduction
Cork reduces sound and noise vibration by trapping it in its cell structure. It reduces the sound transmission of sound through walls and absorbs the impact of feet through the floor to the ceiling below.
- Acoustic Insulation
Cork is used in homes, offices and other buildings to effectively reduce acoustic transmission through walls, floors, and even ceilings. It absorbs the mid to upper frequency ranges and prevents noise transmission and echo.
Advantages of Using Cork
There are many advantages to using cork for soundproofing. It is available in rolls or sheets of different thickness, decorative wall panels, underlay, and ceiling tiles.
It is sustainably renewable, recyclable and lightweight way to insulate against noise. In addition, it is a durable, inexpensive, healthy, and safe way to reduce noise transmission in your home or business.
- Less Expensive
The cost of cork depends on its thickness, size, and the use it is intended for. Cork underlay is less expensive than decorative wall panels or floor boards. Underlay is about 70 cents a square foot and decorative panels $8.50 or higher a square foot. Other comparable products are usually more expensive.
- Health Benefits
Cork is anti-microbial and water resistant, so helps to reduce the growth of mold or mildew. It is antistatic so most dusts and other toxins won’t adhere to it. Cork also has limited off-gassing, so it is good for people who suffer from allergies. It also has a low conductivity so reduces electrical risks.
- Durability and Aesthetic Quality
Cork is available in a variety of colors, textures, and profiles making it an attractive addition to any decor. Aside from reducing noise transfer, it wears well as flooring and resists indenting by furniture. A highly durable product it has many household uses, including hot pads, bath mats, flooring, wall decoration, table coverings, and even furniture.
Cork makes a warm cushiony floor that is easy to clean and care for. The cork has a soft surface that cushions foot falls and impact, making it good for households with children or seniors. The cushioning also reduces the sound transfer and echo of people walking or running.
- Fire Resistant
Cork is fire resistant, not fire retardant. It takes a very high temperature for it to burn or melt and is slow to combust. If it does catch fire, it creates less smoke or chemicals off-gassing than rubber, vinyl or other laminate soundproofing materials.
- Environmentally Friendly
Cork is a sustainably renewable material which is environmentally friendly. It is harvested from trees every 9 to 14 years, and there is very little waste in its manufacture. Carbon trapped in cork doesn’t return to the atmosphere until it is burned or decomposes in landfills; making it even more environmentally friendly.
Cork Noise Reduction Coefficient
The Noise Reduction Coefficient (NRC) measures the average amount of sound an acoustic material may absorb. The scale range is 0 to 1; with 0 meaning no sound was absorbed and 1 that all sound was absorbed. Density and thickness of a material are also factors used when calculating the NRC.
The NRC is usually reported as a percentage. 1-inch thick cork wall tiles have a rating of 0.7, which means 70% of the noise is absorbed and 30% is reflected.
The Sound Transmission Class (STC) is used in the US to rate ceilings, doors, interior and exterior walls, and windows for sound reduction. The ISO (International Organization for Standardization) is similar to the STC, but used outside the US.
Types of Cork Interior Building Materials
Cork has a variety of uses as an interior building material to help reduce sound transfer. Some products are decorative yet functional; others disappear underneath or behind other materials. Cork can also improve the aesthetics and health of your home too.
- Soundproofing underlayment under rigid flooring
Cork is an inexpensive soundproofing underlay. It reduces sound transfer and echo, and is water-resistant. Cork will last for years and doesn’t deteriorate or off-gas noxious fumes like other underlays.
Cork flooring is available in planks, tiles, floating tiles, and rolled sheets. It cushions the floor reducing sound transfer and echo. Combined with cork underlay it will further improve soundproofing. It reduces floor noises plus conversation, TV and other airborne noises.
- Wall Tiles
Wall tiles and panels are available in different colors, thicknesses, textures and decorative styles. They provide acoustic and thermal insulation as well as aesthetically improving the look of a plain drywall interior.
- Ceiling Tiles
Using cork panels or tiles will further soundproof a room. The tiles or panels can be glued to drywall or other rigid material, and then attached to the ceiling or into a drop ceiling grid. It will absorb sound waves and reduce echoes.
Cork Soundproofing Underlayment
Soundwaves radiate from an origin through vibrations which are picked up by the ear as sound. Cork will reduce vibration and decrease noise transfer better than any other material except rubber.
Half-inch thick sheets or panels of cork are used as an underlay to reduce the transfer and echo of noise. The cork goes under other hardwood, laminate, ceramic, porcelain, marble, stone, or cork flooring. It lessens the movement of sound through the floor and within the room itself.
The underlay is secured to the concrete or wood subfloor using a cork underlay adhesive. It not only reduces noise but provides a thermal barrier and helps to prevent cracking from the subfloor transferring through to the finished floor. Use a good cork adhesive and heavy (75 pounds) roller when installing the cork.
A good example of a sound control underlayment is QEP 72003Q 1/4-Inch, 4×25-Foot Cork Underlayment. 100 square feet of coverage to help improve noise reduction and floor heating. With an STC rating of 52 for a 6” concrete floor or an STC of 60 for a 6” concrete floor with a suspended ceiling, it is a great way to reduce sound transfer and echo, plus meet or exceed the building code.
Another good option is Eco Cork Foam Underlayment. It offers 75 square feet of thermal and soundproofing coverage. With a built-in 6 mil vapor barrier, it’s even more resistant to moisture, mold, and mildew.
The cork is 1/8” thick with the vapor barrier so is ideal for radiant heat flooring. With an STC of 66, it will improve noise and thermal reduction.
You may also want to consider QEP 72001Q Natural Cork Underlayment 1/2 inch Sheet. It is available in 25 unit packages of 2’x3’ sheets that cover 150 square feet. With an STC rating of 89, it provides a significant improvement over the minimum rating of 50.
The cork will reduce sound transfer between floor and ceiling, and room to room. It improves in-floor heating effectiveness and room to room sound dampening.
For more information on flooring underlayment, please see our article Best Soundproof Underlayment.
Cork Acoustic Flooring
Cork flooring is a very durable material and has been used for more than 150 years. Many public buildings designed by Frank Lloyd Wright more than 75 years ago, still have their original cork floors. Today it is often used in kitchens and hallways to lessen sound transfer, and cushion feet.
Cork is a sustainable, eco-friendly product. It is water, mold, mildew, and dust resistant which makes a more healthy and natural soundproofing choice. Available in a variety of colors and thicknesses in a roll, plank, tile or floating tile formats, cork is a great choice. It deadens noise transmission and echo helping to sound proof your home or business.The surface nonslip is soft and slightly springy, so feels better on tired feet and legs, or if you fall on it. With proper care it will last for years! An added bonus is it’s also fire resistant.
A good example is the Tasmanian Burl Cork Flooring panels. They are 5/16” thick by 12” by 24”, and packaged to cover 16sqft.
A durable, high-density floor tile that feels soft on the feet. It is easy to cut and fit, light to work with, and is glued to the floor. Resistant to water and fire, it also reduces noise transfer between floors and echo within the room.Another option is a floating cork floor. There’s a gray leather cork Forna plank product made in Portugal. The planks are ½” thick by 11-7/8”x35-7/16” and interlock to form a seamless floor.
With a built-in cork underlay and a finished top cork layer, it reduces impact and noise transfer within a room and between floors. A package will cover about 17-1/2 feet, it’s easy to cut and install, and doesn’t require any glue. It is a non-slip floor and will reduce noise by 23dB.
Acoustic Cork Wall Tiles
Cork wall tiles or panels reduce the movement of sound between rooms and absorb sound within a room to reduce any echo. They also add thermal insulation to a room. Available in a variety of profiles, colors, and thicknesses, they add an aesthetic quality and warmth to any room.The natural material is environmentally friendly and helps improve the air quality for allergy sufferers. Its natural color is dark browns to black but can be lightened with water-based inks or stains. It’s easy to install in any room and will improve sound quality and warmth.
An excellent wall tile product that provides professional level noise reduction is JOCAVI ECOiso Sound Absorbing & Soundproofing Tiles. Available in natural dark brown cork, the tiles are 1.6” thick and 9.8” square; an 18 pack covers 12sqft.
The thicker, high-density cork reduces echo and noise transfer between rooms. The fire retardant tiles also help improve air quality for those who suffer from allergies.You may want to try a larger 12”x36” tile instead of the smaller tile. Forna Cork Wall Tiles are 1/4” thick, and a package covers 66 square feet. With squared edges, it forms a seamless wall that reduces noise transfer, echo, and thermal loss.
Cork absorbs vibration, resists fire, molds, mildew, and insects, and repels dust. The tiles are a great choice for deadening noise and improving the look of a room.
Cork Soundproofing Ceiling Tiles
A cork ceiling will decrease the sound transmission from one floor level to another, and help make the room warmer. It also reduces the echo within a room. There is a wide selection of aesthetically pleasing tiles that can be permanently attached to a drywall ceiling, fitted into a drop ceiling grid, or screwed to open floor joists or an exposed concrete ceiling.
Select a product that is designed for the intended use, or it may not stay on the ceiling; the higher the density, the better. Cork panels that are 13/16” thick will reduce sound transmission by more than 30dB, 1-9/16” more than 40dB, and 2-7/16” by about 50dB. A great way to reduce sound transmission from the TV room, rumpus room, or noisy neighbors!JOCAVI ECOiso Sound Absorbing & Soundproofing Cork Acoustic Panels are a great choice. Made of natural eco-friendly cork, the panels are 19.7”x39.4” and 2.4-inches thick. The extra thick high-density cork suppresses approximately 50dB of sound, making it an excellent noise barrier between floors, and within a room. Available in a 6-pack that covers 32sqft, the square edged tiles can form a seamless soundproofing barrier between you and the tenants above or the kid’s playroom.
Is cork fire resistant? Cork is a very dense material with a high combustion temperature, about 390°F, making it a natural fire retardant. It is slow to spread flames and doesn’t release toxins during combustion. Its low conductivity to heat, vibration and sound also explain why it is used to make engine gaskets.