Is Fiberglass Insulation Good for Soundproofing?


If you are struggling with a lot of noise in your home, you have probably tried a lot of things to make it quieter.

Noisy traffic being the most common and those neighbors that are playing loud music and having late parties are never helping either.

The noise can also lead to an unhealthy life, and no one wants that for themselves.

Problems like sleeplessness and high level of anxiety are just that common and noise is one of the leading factors.

Apparently, it would be the best to stop it. But how?

A bunch of information is always available on the Internet, but it is rarely certain that that information is actually correct.

Most important question when it comes to sound insulating is always which materials are right to use for this purpose.

fiber glass panels

And if you’re looking for the best pipe insulation – materials are a great place to start with.

One of the most common solutions to the noise problem in your home is suggested to be fiberglass.

But is it really as efficient as they say?

As you know, I dedicated a past few years of my life to finding solutions to noisy homes, cars, and appliances of different types.

Now is the time to find the final answer to the question “Is fiberglass insulation good for soundproofing?”

Is Fiberglass Insulation Good for Soundproofing?

what type of insulation is best for soundproofing?

Most of the materials that are suggested act as some kind of soundproofing barriers.

The thing is the more power a sound wave needs to overcome that obstacle, the quieter it will be on the other side.

If you manage somehow to exhaust all of the sound wave’s power, you are left at peace, and the sound will not be heard on the other side at all.

And let’s be honest here, layers are always additional obstacles for the sound and they can never be wrong when it comes to soundproofing.

However, an utter insulation is not that likely to happen.

If you’re looking to sound proof your home 98% - you would need to rely on sound deadening ceiling insulation so you have your whole place covered.

Some of the materials are good at blocking one type of noise and wavelengths; the others are good with the different type of noise and wavelengths.

Therefore, you’ll need to pay attention to the the acoustic barrier material you’re using – and luckily for you, if you keep on reading, that’s exactly what you’ll find out in this post.

But you will never be able to live in complete silence. Maybe even better, since complete silence can drive you mad.

But then again, so can a lot of noise.

For complete silence, you would need to build anechoic chambers around your house, but some level of soundproofing should be enough after all.

Another thing that you need to know before you start soundproofing is that there are two types of soundproofing:

  • Sound absorbing – this one would mean that the materials used would capture the unwanted sounds in their threads and not let it bounce off of the surfaces that easily, since they are, in most of the cases, a little bit softer;
  • Sound blocking – sound blocking would often mean that the materials used are very thick and not at all flexible, so they will be able to stop the vibrations and expansion of the noise on the other side of the blockade.

Soundproofing with Fiberglass: Yay or Nay

More or less, any material will be able to block the noise to some level, but the question that rises from here is if that level would be high enough for you to have your peace and good sleep restored.

And now that we know a few things about insulation, let us go back to the fiberglass and its strengths.

The simple answer to the question “Is fiberglass insulation good for soundproofing?” would be yes; but still no.

Even though this answer might seem a little confusing, there is a perfectly good explanation. And I will give it to you in a second.

Soundproofing with Fiberglass

So hold on a bit with the fiberglass board purchase just yet!


Let’s start with the “Yay” part.

Fiberglass is very good at absorbing the sound; much better than it is with blocking it.

To be fair, fiberglass is maybe the best material for soundproofing there is when it comes to sound absorption.

If you are wondering where it is mostly used, I would say that fiberglass is used in business buildings where there are a lot of offices and a lot of corporate meetings and phone calls.

It has shown to be good in absorbing the chatter and bringing it to a minimum.

The benefits that you can expect from fiberglass are, again, absorption of the sound, and the reduction rate of noise that you can expect from it would be up to five decibels, and probably not less than three.

The fiberglass layer is often just a few inches thick, and you can’t expect wonders from it.

what type of insulation is best for soundproofing


And this is the “nay” part.

The thing that fiberglass is not capable of doing is a complete blockage of the noise coming from either within the building or from the outside.

Now don’t get me wrong. I am not talking only about corporate buildings; I used it just as an example to show you that it is good in absorbing the buzz of a conversation and chatter.

It will most likely do much better in your own home than it is in a building that is constantly full of people.

If you were thinking about using a thicker layer of fiberglass in order to block the sound completely, I would advise you to give up before you even try.

In order to use it as a sound blockader, and not absorbent, you would need to install something like 3 feet thick a layer, and that is, as you can just imagine, highly impractical; especially if it is your own home that you are trying to soundproof.

Another thing that would place fiberglass in the “yay” answer would be the additional type of insulation that it provides, and that is heat insulation.

Since I already mentioned that it is not so good at blocking the sound, it can be used as a fantastic addition to the material that you choose to use as a blockade.

Mass Loaded Vinyl

To Use It or Not to Use It

If you want to know my opinion on whether to use fiberglass in your sound insulating projects or not, I would always say “yes”.

If you are wondering why when it is not so good at blocking the noise, here is a simple answer.

Blocking the sound is good when it comes to the noise that is coming from the outside, but what will you do with the noise inside of the house?

And once again, it all comes down to sound absorption.

The noise inside of a room has a tendency to jump from wall to wall and echo, and that is something that is making an uncomfortable noise that you are might not even aware of.

If you can find a way to reduce this echo, it will seem to your ear that the level of noise in the room is brought to a much lower level.

Let me explain it once again: if you have a flat and hard surface, it would make a fantastic ground for a sound to jump off of it, and then of the opposite wall, and so on.

This is how the echo is created.

But if you find a way to stop this bouncing by adding something that can absorb the noise, it is certain that you will be able to hear the difference.

Or not hear, to be precise.

Sound waves

However, when it comes to completely soundproofing your home from the outside noise, I wouldn’t advise you to use fiberglass as an only solution, since it would be much better in a combination with some other materials. 

If you want to achieve a fully sound proof box and you rely on fiberglass – you’d end up combining it with plenty of other sound isolation materials.

Fiberglass serves best as just one milestone of the whole soundproofing task.

Materials to Use Fiberglass with

Some materials have always been better in sound insulating than the others, and it is a well-known fact.

Have in mind that soundproofing is a big project, and it would be the best if you chose the right materials from the start.

It is highly unlikely that you can choose only one material and make it work for every type of noise and every wavelength there is.

In the end, it all comes down to picking the right combination of the materials.

The best way to get both sound absorbing properties and sound blocking properties from your soundproofing project is to help the fiberglass insulation with materials that serve as blocking panels.

soundproof foam

Blocking panels can be made of materials such as gypsum boards that you can place both on walls and ceiling, and an additional layer of drywall.

Here are some of the best acoustic panels for your consideration.

But keep in mind that you’ll also want to soundproof your doors and windows as well.

Door sound muffler or rolled insulation are great insulation solutions for this.

Additionally, if you want to go all the way in – you should consider soundproofing floors as well (especially if you live in a building) with the materials such as roockwool sound insulation that is ideal between floors

So, Is Fiberglass Insulation Good for Soundproofing?

Now that I have said everything that I knew about fiberglass and its benefits, I hope that I have answered some of your dilemmas.

To summarize, fiberglass is a fantastic sound absorbent and very good when it comes to reducing echoes inside of a room, but not the best one when it comes to blocking the outside noises.

Additionally, it is a fantastic heath insulator, and it comes in handy when you are using it as an addition to more serious materials in soundproofing business.

But you have to consider the place you live in and what other insulation solutions would you need to combine in order to create a soundproof living space.

Fiberglass panels are ideal for soundproofing, and definitely, use it as a part of your project, and bring your well slept nights back to your life.

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