If you want to reduce noise in a room, you may be asking yourself the question; “is styrofoam good for soundproofing?” You’ve seen Styrofoam before. It’s that white stuff that takeaway boxes are made from and that provides cushioning in packaging for electronics. It looks like it might be handy for blocking noise – but is it?
Styrofoam is a brand of polystyrene that is used more for thermal insulation than it is for sound insulation. But it certainly has some soundproofing qualities.
In this Styrofoam soundproofing guide, we’ll examine whether Styrofoam should be used for soundproofing. We’ve analyzed Styrofoam’s pros and cons for soundproofing, so that we can present you with the best possible advice on if, and how, it should be used for your soundproofing needs.
We’ve also explained what Styrofoam is, how it is manufactured, and compared it to other types of polystyrene and soundproofing materials.
Want to get straight to Styrofoam’s benefits and best uses? Jump to the section you require below…
Skip to:
- What is Styrofoam?
- How is Styrofoam made?
- How effective is Styrofoam for soundproofing?
- Pros and cons of Styrofoam for soundproofing
- The best uses of Styrofoam for soundproofing
- Alternative soundproofing materials
What is Styrofoam?
You’ve almost definitely seen Styrofoam before. It is used for the white inserts that protect your electronics items (such as TVs or speakers) in the packaging. And you have probably eaten a takeaway burger from a Styrofoam box.
Styrofoam is also commonly referred to as polystyrene. It is a brand of polystyrene that is made by DuPont, the American chemicals corporation formed in 1802. Styrofoam is used for various applications including packaging materials, disposable containers such as burger boxes and coffee cups, and for insulation in construction. Styrofoam is primarily used for heat insulation, but that’s not to say it doesn’t have any sound insulation properties – after all, that’s what we’re here for, right? We’ll come on to its potential for sound insulation in the ‘How effective is Styrofoam for soundproofing?’ section
Styrofoam comes in 2 main types. Expanded polystyrene (EPS) foam is the type that you see in packaging materials and disposable food containers. It is lightweight, consists of fused polystyrene beads, and has quite a rough surface. Extruded Polystyrene (XPS) Foam is the type that is used in construction for insulation. XPS panels are more rigid and have a smooth surface which makes them waterproof.
Unless you work in the construction industry or are a regular DIYer, EPS – the white, lightweight form of Styrofoam – is what you will be most familiar with. XPS typically comes in more rigid pink or blue panels suited to wall, ceiling, or floor installation.
How is Styrofoam made?
EPS Styrofoam, the type commonly used in packaging, is made by infusing heat or steam into a mold that holds polyester beads. This has the effect of causing the beads to expand and fuse, resulting in the Styrofoam you see in many applications.
XPS Styrofoam, the type used in construction, is made by heating and extruding (forcing out) the polystyrene beads, which results in rigid, tough panels that can be used for thermal insulation.
How effective is Styrofoam for soundproofing?
Now we’ve nailed down a definition of Styrofoam, distinguished the different Styrofoam types, and explained how Styrofoam is made – let’s look at whether Styrofoam is helpful for soundproofing.
The truth is, Styrofoam is more suitable for providing heat insulation than it is for soundproofing.
As a sound blocker, it is inferior to materials such as mass loaded vinyl, acoustic mineral wool, or soundproof drywall. The main reason for this is that Styrofoam doesn’t have the density of these soundproofing materials, meaning it doesn’t provide as much mass for soundproofing.
Remember – adding mass is one of the key principles of soundproofing.
As a sound absorber, Styrofoam isn’t as effective as substances such as acoustic foam. That’s because of Styrofoam’s closed cell structure, which doesn’t allow air in. This is why it is dense for a lightweight material, making it suitable for packaging, but is unable to absorb sound waves and reduce echoes in your room.
However, despite not being the best sound blocker, and not being able to absorb sound, Styrofoam can help with soundproofing when used in conjunction with other materials.
Used with partner materials, Styrofoam can be a good decoupler, helping to stop sound transmission in conjunction with other soundproofing layers. The most obvious example of this is the XPS Styrofoam that is used in construction for thermal insulation. It sits in between two layers of drywall in a wall cavity, and in this position, it can have the effect of decoupling the wall and disrupting the sound transmission path between two sides of a wall.
If you want to get a better grasp on the technical side of decoupling, here’s a direct link straight to the info in our How to Soundproof a Wall from Noisy Neighbors article
Styrofoam vs acoustic foam
If you have been tempted to use Styrofoam for soundproofing, or at least consider the idea, it may have been due to its similarity with acoustic foam.
Acoustic foam, often seen with its ‘egg box’ design, is a common sound absorption solution that you can use to improve acoustics in a room. You might have seen it in recording studios. Like Styrofoam, it is lightweight, cheap, and readily available. However, the reason why acoustic foam is much better at absorbing sound and improving acoustics than Styrofoam comes down to its structure.
While widely known as acoustic foam, the full title of acoustic foam is open-cell polyurethane foam. Figured out where we are going with this? Because acoustic foam has an open cell structure, it is a much better sound absorber. Sound waves get trapped in this open cell structure and are absorbed, reducing the echo and reverberation in a room. Many types of acoustic foam has a noise reduction coefficient (NRC) of 0.6 or higher, meaning it will absorb at least approximately 60% of the sound waves that reach it. (This NRC rating varies according to the thickness of the material and the frequency of the sound). Comparably, Styrofoam has hardly any sound absorption capability.
With its absorptive qualities – acoustic foam is better at sound dampening than Styrofoam.
What is sound dampening? Sound dampening is the ability of a material or structure to reduce the vibrational energy of a sound wave. That is, to decrease the amplitude of a sound wave.
We’ve summed up the soundproofing abilities of Styrofoam vs acoustic foam in the table below:
| Attribute | Styrofoam | Acoustic foam |
| NRC rating | up to 0.2 | 0.6 or higher |
| Sound dampening ability? | No | Yes |
| Sound blocking ability? | Some | No |
Pros and cons of Styrofoam for soundproofing?
So to recap, we’ve explained that although Styrofoam is not the best material for soundproofing and can’t absorb sound, you can use it to block sound in combination with other materials.
Here are the pros and cons of using Styrofoam for soundproofing
Pros of Styrofoam for soundproofing
Lightweight – as you know from opening a new electronics product or eating from a Styrofoam container, it is a light material that anyone can handle.
Widely available – boards of XPS Styrofoam are easy to buy online and at your local DIY stores.
Thermal insulation – Styrofoam’s primary use is for heat insulation, so you’ll have a dual benefit if you use it for soundproofing.
Inexpensive – one of the cheapest materials you could find for soundproofing.
Cons of Styrofoam for soundproofing
Negligible sound absorption – you’ll find that Styrofoam is way behind acoustic foam for its absorptive abilities, due to its closed cell structure. So it really won’t be much good for reducing echo and reverberation within a space. Our advice? For sound absorption, don’t bother.
Limited for sound blocking – although it can block some sound, Styrofoam isn’t much use on its own. It doesn’t have the same mass and density as tried and trusted sound blockers such as mass loaded vinyl or mineral wool.
Other materials required – if you are going to use Styrofoam for soundproofing, it needs to be used in combination with other layers for effective soundproofing, e.g. drywall or materials such as mass loaded vinyl.
Limited blocker of low frequencies – Styrofoam is able to catch and dissipate sound much better with mid or high frequencies, than low frequency noises such as traffic or machinery.
The best uses of Styrofoam for soundproofing
Styrofoam can help with soundproofing when incorporated into the construction of a wall. But its main benefit is as a thermal insulator.
If you are constructing a property, or soundproofing the walls in a room, you can use styrofoam as insulation in between drywall. There it can help as a sound blocker by giving a decoupling effect, as well as providing the heat insulation that it is best used for.
Styrofoam is a convenient choice for a general insulator due to its light weight, low price, availability, and versatility. But Styrofoam is not the answer for a peaceful life – you shouldn’t rely on Styrofoam alone to make a significant impact on noise reduction in your home.
And while Styrofoam can help you with blocking sound, it certainly won’t be a good sound absorber. So apologies to all those enterprising DIYers, music producers, or musicians who thought that the white cushioning in their new TV box could help to reduce echo if stuck on a wall. Remember… Styrofoam is completely different from acoustic foam. Acoustic foam has an open cell structure that can absorb sound waves, whereas Styrofoam has a closed cell structure that will not absorb sound and reduce echo.
If you want a material that offers the best soundproofing ability on its own – by this we mean the ability to cut sound transmission between two rooms or properties – turn your attention to other options such as mass loaded vinyl, soundproofing drywall, and mineral wool. These materials have a superior density and more mass, making them more effective for soundproofing.
Alternative soundproofing materials
Below is a bit more information on alternative materials for soundproofing that will probably do a better job than Styrofoam. We will help you understand why these materials will do a better job of blocking or absorbing sound in your room, and detail any other benefits
Mass loaded vinyl – versatile and easy to install; mass loaded vinyl is a great sound blocker, making it a true soundproofing material. Like polystyrene, it is best for soundproofing when installed within a wall, floor, or ceiling. But you will find mass loaded vinyl is much more effective than Styrofoam at reducing sound transmission because it is denser, so adds more mass.
Mineral wool – usually made from slag or basalt, mineral wool is a great choice for noise insulation. It comes in batts that are easily installed in walls, and is an effective sound blocker. It is also an excellent sound absorber, with a noise reduction coefficient as high as 0.8, meaning it can absorb as much as 80% of sound at certain frequencies. This will also depend on the thickness of the mineral wool. Also, it offers much better fire resistance than Styrofoam.
Acoustic foam – if your aim is to reduce echo and reverberation in a room, improving acoustics, then acoustic foam is a much better option than Styrofoam. Due to its open cell structure, it can capture sound waves and stop noise from reflecting off surfaces in your studio, music room, or study. Like Styrofoam, acoustic foam is inexpensive and lightweight.
Cork panels – if you want the heat insulation offered by polystyrene but with the added benefit of sound absorption, consider cork panels. Cork is one of the best sound absorbing materials, with a noise reduction coefficiency rating as high as 0.7, meaning it takes in, rather than reflects, 70% of the sound that hits it. As well as installing wall insulation, cork can be a good choice for tiling or underlayment for floors, giving you better acoustics.
Green Glue – as we’ve mentioned, Styrofoam can offer you some soundproofing capabilities used with partner materials. But if you want a substance to augment the soundproofing materials you are using, Green Glue may be a better bet. You just need to spread a thin layer on drywall to boost the sound absorption and blocking capabilities of a wall. It also fulfills one of the main purposes of soundproofing really well: Filling gaps, cracks, and joints.
