I’m always looking for new and accessible products to use in soundproofing projects. Someone recently asked me, “Does cork flooring absorb sound?” I was curious to know, so decided to research it further. Here’s a quick answer:
Cork flooring absorbs sound very well. Its open structure and soft composition means it has a noise reduction coefficient of 0.7. When used correctly, it can absorb up to 70% of airborne and impact noise. A simple 3mm layer of cork can reduce sounds by up to 10dB.
In this article, I’ll go into a bit more detail about why cork is so good for soundproofing, and how you can easily use it in your next project. Hopefully, by the end, you’ll see why cork flooring is so good.
Cork Flooring’s Sound Absorption Coefficient
Sound absorption is measured in something called the Noise Reduction Coefficient (NRC), or sound absorption coefficient. For the purposes of this discussion, it’s enough to know that they’re essentially the same thing.
NRC is measured on a scale of 0-1, with 0 meaning the material reflects sound waves and 1 meaning it completely absorbs sound waves. For a material to be worth using in soundproofing, it has to have an NRC of over 0.4.
As I mentioned, cork flooring has an NRC of 0.7, which means it absorbs up to 70% of sound waves and reflects the remaining 30%. Mass loaded vinyl (Amazon link) has an NRC of 0.8, so you can see how effective cork really is.
But why is cork so good at absorbing sound?
You may already know, but cork is made from the bark of the Cork Oak tree. It’s widely used in a number of industries because of its lightweight and open structure.
This makes it great for thermal insulation, but also for sonic insulation.
Cork can be up to 50% air. While this is lower in cork flooring tiles, which are usually made from chipped and compressed cork, they still contain enough air to effectively absorb sound.
When something makes contact with cork, such as footsteps or an airborne sound, the cork compresses.
This deadens the impact, which reduces the amount of noise it makes. Similarly, the air pockets in cork work in much the same way as acoustic foam panels.
Sound waves are able to enter the material’s open structure, but can’t get out. They bounce around off multiple surfaces and expend their energy in the process. This is what makes cork a sound absorber.
In short, cork is excellent for absorbing and dampening sounds because of its open structure and air pockets. Along with this, there are several other benefits to using cork in your soundproofing projects.
The Advantages of Using Cork Flooring
Cork panels (Amazon link), whether designed for flooring or walls, are a great addition to almost any soundproofing project. Here’s why.
Cork is a massively sustainable product. It’s completely natural and doesn’t require cutting down the tree during harvest.
The bark is simply stripped off the tree and grows back in roughly 9 years. In fact, cork trees can live up to 300 years!
Compared to specialist soundproofing materials, cork is very inexpensive. Like for like, it costs roughly half the price of mass loaded vinyl, and is cheaper by area than foam panels.
Better for your health
Some soundproofing products use chemicals during production, which can be problematic if you have allergies. Even if you don’t, they can smell when you first unpack them.
Cork, however, requires little or no other materials during production. There might be some glue, but that’s about it.
What’s more, cork is water-resistant and anti-microbial. This means it won’t develop mold or mildew, even if it’s used in damp environments.
Finally, cork is incredibly durable. It can withstand very heavy impacts, doesn’t tear easily, and will last a long time, even in less-than-perfect conditions.
Cork is surprisingly fire resistant and has a combustion temperature of around 390 degrees F. Even if it does catch fire, it doesn’t release any toxic fumes and burns very slowly.
As you can see, there are plenty of reasons why cork is a great addition to your next project. It’s really easy to buy in bulk, so it won’t be long until you’ve covered your whole house in it!
Check out my article: Best Underlayment For Soundproofing A Floor
How to Use Cork Flooring in Your Soundproofing Project
There are a number of different ways you can bring cork into your DIY projects. It works great as thermal and sound insulation and comes in a variety of materials.
Here are my top suggestions for how to bring it into your next project.
1. Cork floor underlayment
Cork floor underlayment (Amazon link) goes under either carpet or hardwood floor.
It’s perfect for providing another layer of insulation and sound dampening.
If you’re relaying a floor, consider using this product because it’ll drastically reduce the amount of impact noise transfer into the floor below.
2. Main floor material
While cork functions perfectly as floor underlayment, you can also use it as the main floor material.
It’s been used as such for over 150 years, and can last up to 80 years in the right conditions.
Some companies provide many different designs, meaning you don’t have to be restricted to just the standard cork pattern.
It’ll still provide the same level of absorption, but you could combine it with cork underlayment for even better results.
3. Cork wall tiles
Along with insulating your floor, you can also use cork for insulating your walls too.
Cork tiles (Amazon link) are perfect for adding to a sheet of drywall to improve its sound dampening properties.
Much like acoustic foam, you’ll need to include it on the outside of the wall. After all, it won’t do a good job if hidden inside the wall cavity.
While this might not be the best look, you can easily turn it into a rustic room design. Also, it’ll double up as a wall-sized pinboard!
4. Using cork on solid surfaces
Many of us will likely have cavities in our wall and ceiling spaces around the home. But if for any reason you have solid walls or floors, such as concrete, cork will be the perfect addition.
Concrete has an NRC rating of around 0.2, which is pretty bad. While sounds will have a difficult time passing through solid concrete, they will reflect off its surface.
This can create horrible echo and reverberation in a space, which is less than ideal.
Luckily, cork panels absorb sound but can also be used to treat a space’s acoustics.
If you attach cork flooring panels to concrete surfaces, whether walls, floor, or ceiling, they’ll help to massively reduce sound reflection.
What’s more, they’re really easy to stick up with some Green Glue, which will improve its sound dampening. Just be careful not to apply too much, as the glue will clog up the cork’s pores.
Some Final Thoughts
In my opinion, cork flooring is a great addition to your soundproofing arsenal. It absorbs sound waves, is sustainable, and is inexpensive.
Hopefully, I’ve managed to convince you of the benefits of cork flooring. Why not try it out next time you need to soundproof a room?