Is Fiberglass Insulation Good For Soundproofing 🤫🔇 Keep It Quiet!

Photo of author

Written by: Mohammad Sameer

Published on:

“Is Fiberglass Insulation Good For Soundproofing?” – a question many of us ponder while seeking peace in our noisy world.

After thorough research, the answer is yes, but with nuances.

Fiberglass, known for its sound-absorbing properties, is effective in reducing noise transmission and enhancing living spaces with tranquillity​​​​.

ceramics online library Wiley (2023) explored the fundamental aspects of heat transfer in fibrous insulation, providing mathematical formulations for the effective thermal conductivity of fiberglass insulation, influenced by factors like insulation density, fiber diameter, and temperature.

Is Fiberglass Insulation Good For Soundproofing?

Yes, fiberglass insulation is widely recognized as a good material for soundproofing. It is especially effective for absorbing airborne noise, like conversations or music, and can also dampen impact noise to some extent.

Fiberglass insulation contributes to improving the Sound Transmission Class (STC) rating of a building structure.

The STC rating is a measure of how well a partition can reduce airborne sound.

While the exact STC rating improvement depends on various factors like the thickness of the insulation and the construction of the wall, generally, adding fiberglass insulation to interior walls and floors/ceilings can enhance the STC rating, making your space quieter and more serene​​.

In terms of a noise reduction percentage, fiberglass insulation can reduce noise levels by up to 5 decibels, which is significant in making a space quieter.

However, it’s crucial to note that fiberglass is more effective at absorbing sound rather than blocking it completely.

For areas where complete sound blocking is needed, additional soundproofing measures might be required alongside fiberglass insulation​​.

The Science of Sound Absorption

Sound travels in waves, and when these waves encounter a material like a fiberglass, the material’s structure plays a crucial role in determining how much sound will be absorbed or reflected.

Fiberglass insulation, composed of a dense web of fine fibers, is particularly adept at trapping sound waves. Here’s why:

  • Density Matters: The denser the material, the more sound it can absorb. Fiberglass insulation comes in various densities, allowing customization based on specific soundproofing needs.
  • Thickness Plays a Role: Sound absorption’s effectiveness increases with the insulation’s thickness. Thicker layers of fiberglass provide better sound dampening.
  • Fiber Arrangement is Key: The random arrangement of fibers in fiberglass insulation creates a maze for sound waves, forcing them to bounce around and lose energy, thus diminishing their intensity.

Airborne vs. Impact Noise – Fiberglass’s Dual Role

image of Airborne vs. Impact Noise – Fiberglass's Dual Role

Understanding the types of noise is crucial when considering soundproofing solutions.

Airborne noise, like conversations or music, and impact noise, such as footsteps or machinery vibrations, are the two main categories.

Here’s how fiberglass insulation addresses each type:

  • Airborne Noise: Fiberglass insulation is a champion at absorbing airborne sound waves, preventing them from travelling through walls and ceilings.
  • Impact Noise: While not as effective as specialized materials, fiberglass can still dampen the vibrations caused by impact noise, especially when combined with other soundproofing techniques.

The Technical Side – STC Ratings Explained

The effectiveness of soundproofing materials is often measured by the Sound Transmission Class (STC) rating.

The higher the STC rating, the better the material is at reducing sound transmission.

For instance, a wall with an STC rating of 40 will allow loud speech to be heard but not understood through it, indicating substantial sound reduction capabilities.

Fiberglass insulation, when properly installed, can significantly improve the STC rating of a wall or ceiling assembly.

Did You Know? A study by the Insulation Institute reveals that adding fiberglass insulation to interior walls and floors/ceilings can enhance the STC rating, making your space quieter and more serene​​.

Advantages and Potential Drawbacks of Fiberglass Insulation in Soundproofing

Fiberglass insulation is often the go-to solution for those looking to create a quieter space, but like any material, it comes with its own set of strengths and weaknesses.

Let’s delve into the pros and cons, giving you a well-rounded view of what to expect when considering fiberglass for your soundproofing needs.

Advantages of Fiberglass Insulation

The benefits of fiberglass insulation are noteworthy, and it’s these advantages that make it a popular choice in the world of soundproofing.

  • Cost-Effectiveness: Fiberglass insulation is known for being affordable, making it an accessible option for many homeowners and builders.
  • Ease of Installation: It’s user-friendly and perfect for DIY projects, allowing you to take the soundproofing of your space into your own hands.
  • Versatility: Suitable for standard stud and joist spacing, fiberglass fits seamlessly into most building structures.
  • Dual Functionality: Not only does it absorb sound, but it also serves as thermal insulation, keeping your space comfortable and quiet.
  • Environmental Friendliness: Fiberglass contains recycled glass and is itself recyclable, contributing to a lower environmental impact.

Fast Fact: According to a report, installing fiberglass insulation can improve the Sound Transmission Class (STC) rating of a wall or ceiling, indicating its robust soundproofing capabilities​​.

Potential Drawbacks of Fiberglass Insulation

While the advantages are compelling, it’s crucial to also consider the potential drawbacks to make an informed decision.

  • Skin and Respiratory Irritation: The tiny particles of fiberglass can cause rashes, itchiness, and respiratory issues if not handled with proper safety gear.
  • Airflow and Moisture Concerns: Fiberglass allows airflow and can trap moisture, potentially leading to discomfort and mold growth if not properly managed.
  • Not a Complete Sound Blocker: While excellent at absorbing sound, fiberglass doesn’t completely block noise, especially from external sources.
  • Low-frequency Limitations: It’s less effective against ultra-low bass frequencies, which may require additional soundproofing measures for optimal results.

Did You Know? Despite these drawbacks, combining fiberglass with other materials, like mass-loaded vinyl or double drywall, can significantly enhance its soundproofing effectiveness, offering a more comprehensive solution to noise control​​​​.

Comparing Fiberglass Insulation with Other Soundproofing Materials

image of Comparing Fiberglass Insulation with Other Soundproofing Materials

When it comes to creating a peaceful and quiet environment, choosing the right soundproofing material is crucial.

Fiberglass insulation is a common choice, but how does it stack up against other materials in the market?

Let’s explore how fiberglass fares against its competitors in terms of soundproofing efficiency, cost-effectiveness, and ease of installation.

Fiberglass vs. Rockwool Insulation

  • Sound Absorption: Both materials are excellent at absorbing sound, but Rockwool has a slight edge, especially for low-frequency sounds.
  • Fire Resistance: Fiberglass and Rockwool are non-combustible, but Rockwool can withstand higher temperatures.
  • Ease of Installation: Fiberglass is generally easier and less irritating to install compared to Rockwool, which requires more protective gear due to its denser fibers.
  • Cost: Fiberglass often comes out as the more budget-friendly option, offering a good balance between performance and price.

Fiberglass vs. Foam Insulation

  • Soundproofing Qualities: Foam insulation, particularly Closed-cell Foam, is more geared towards thermal insulation. However, it provides good sound-blocking capabilities, unlike fiberglass, which excels in sound absorption.
  • Installation: Foam insulation can be more complex to install, requiring professional equipment for spray applications.
  • Cost Comparison: Foam insulation is generally more expensive than fiberglass, considering the material cost and installation requirements.

Fast Fact: Approximately 25% of homes utilize fiberglass insulation to reduce noise, making it one of the most popular soundproofing materials on the market today​​​​​​.


Does Fiberglass Insulation Help With Sound

yes, fiberglass insulation does help with sound. it is a popular choice for soundproofing due to its ability to absorb sound waves, reducing the overall noise level. however, it’s important to note that while fiberglass is good at absorbing sound, it doesn’t block it completely.


In exploring the query, “Is Fiberglass Insulation Good For Soundproofing,” my research confirms its efficacy.

Fiberglass effectively absorbs sound, enhancing tranquillity in your space, though it’s not a total blockage solution​​​​.

For comprehensive soundproofing, it pairs well with other materials, offering a practical, cost-effective choice for noise reduction.

Sharing Is Caring:

About Mohammad Sameer

My name is Mohammad Sameer, the founder of SoundproofGears. My hypersensitive hearing turned me into a lifelong seeker of silence. After years of research, I've become an expert on soundproofing techniques and materials. In November 2022 I launched this site to share my knowledge and help others find acoustic sanctuary. About More