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  • Writer's pictureJulian Rhodes

Is Spray Foam Good For Soundproofing? | Our Verdict

In today's world, noise pollution has become a significant concern for homeowners and businesses alike. One solution that has gained traction in recent years is the use of spray foam insulation for soundproofing purposes. In this guide, we will explore the effectiveness of spray foam insulation in reducing noise, delve into its properties, and provide a detailed comparison with alternative soundproofing solutions.

Is Spray Foam Insulation Good for Soundproofing?

Yes, spray foam insulation can reduce noise by absorbing sound waves and preventing them from travelling through walls and ceilings. However, its primary purpose is to improve thermal insulation.

The Science Behind Spray Foam Insulation and Noise Reduction

Spray foam insulation is a popular choice for thermal insulation and air sealing in residential and commercial buildings. Its effectiveness in noise reduction can be attributed to its composition and properties.

Composition of Spray Foam Insulation

Spray foam insulation is a polyurethane foam, which consists of two main components: polyol and isocyanate. When these two chemicals are mixed, they react and expand rapidly, creating a foam with a cellular structure. This foam can be categorized into two main types:

  1. Open-cell foam: Open-cell spray foam is more flexible and has a lower density, making it ideal for sound absorption. Its open-cell structure enables it to trap air and soundwaves, reducing noise transmission.

  2. Closed-cell foam: Closed-cell spray foam has a higher density and is more rigid, making it an excellent choice for thermal insulation and structural reinforcement. Although it is not as effective as open-cell foam for sound absorption, it still provides a degree of noise reduction due to its mass and density.

Sound Transmission Class (STC)

The effectiveness of a soundproofing material is measured using the Sound Transmission Class (STC) rating. A higher STC value indicates a better ability to block sound transmission. Open-cell spray foam typically has an STC rating of 39-43, while closed-cell spray foam ranges from 35-38. Although these values are lower than some dedicated soundproofing materials, spray foam insulation can still provide a noticeable improvement in noise reduction when installed correctly.

Comparison with Alternative Soundproofing Solutions

To better understand the effectiveness of spray foam insulation in reducing noise, let's compare it with other soundproofing materials.

Mass Loaded Vinyl (MLV)

Mass Loaded Vinyl is a heavy, flexible material specifically designed for soundproofing purposes. It has an STC rating of 26-32, making it less effective than open-cell spray foam insulation. However, MLV can be combined with other materials to create a more comprehensive soundproofing solution.

Acoustic Panels

Acoustic panels are typically made from fiberglass, foam, or other porous materials, and are designed to absorb soundwaves. They have an STC rating of 20-35, depending on their thickness and composition. While they can effectively reduce noise, they are not as versatile as spray foam insulation, which can also provide thermal insulation and air sealing.

Drywall and Green Glue

Adding an additional layer of drywall with a viscoelastic compound such as Green Glue in between can significantly increase the STC rating of a wall. This combination can achieve an STC rating of up to 52, making it a more effective soundproofing solution than spray foam insulation alone.

See our post on the 7 best ways to soundproof your home here.

Maximizing Noise Reduction with Spray Foam Insulation

To get the most out of your spray foam insulation in terms of noise reduction, consider these tips:

  1. Choose open-cell foam: For the best noise reduction, opt for open-cell spray foam insulation, which has a higher STC rating and is more effective in absorbing sound.

  2. Combine with other soundproofing materials: Enhance the effectiveness of spray foam insulation by combining it with other soundproofing materials, such as MLV or acoustic panels.

  3. Seal gaps and cracks: Spray foam insulation can also help reduce noise by sealing gaps and cracks in walls, ceilings, and floors. This prevents sound from travelling through these openings and further improves soundproofing.

  4. Proper installation: Ensure that spray foam insulation is installed correctly by a professional. This will ensure that the material provides optimal noise reduction and avoids any potential issues.

  5. Consider room layout: The arrangement of furniture and other objects within a room can impact the effectiveness of spray foam insulation. Optimize the layout to minimize noise transmission between rooms.

The Benefits of Spray Foam Insulation Beyond Noise Reduction

In addition to its noise-reducing capabilities, spray foam insulation offers several other benefits:

  1. Energy efficiency: Spray foam insulation provides excellent thermal insulation, which can help reduce energy consumption and lower utility bills.

  2. Air sealing: By filling gaps and cracks, spray foam insulation creates an effective air barrier, preventing drafts and improving indoor air quality.

  3. Moisture control: Closed-cell spray foam insulation is resistant to water and moisture, reducing the risk of mould and mildew growth.

  4. Structural reinforcement: Closed-cell spray foam can add structural integrity to walls and other building elements, providing additional support and stability.


Spray foam insulation is an effective solution for soundproofing homes and commercial spaces. The choice between open-cell and closed-cell foam depends on the desired level of soundproofing and the specific application. By following the installation tips outlined in this guide, you can significantly reduce noise transfer and create a more peaceful environment. Remember to consider all available soundproofing methods and consult with professionals to determine the best solution for your needs.

Frequently Asked Questions (FAQs)

Q1: Does spray foam soundproof walls?

Yes, spray foam insulation can help soundproof walls by creating an air barrier and reducing the transfer of sound waves. The effectiveness of soundproofing depends on the type of foam used (open-cell or closed-cell) and the quality of the installation.

Q2: What kind of foam is best for soundproofing?

The choice between open-cell and closed-cell foam depends on your specific soundproofing needs. Open-cell foam is more effective at absorbing sound waves, making it suitable for residential applications, while closed-cell foam provides better sound-blocking capabilities, making it ideal for commercial and industrial use.

Q3: Can you soundproof a room with just foam?

While spray foam insulation can significantly reduce noise transfer, it may not completely soundproof a room on its own. For optimal results, consider combining foam insulation with other soundproofing techniques, such as adding mass to walls, using resilient channels, or installing acoustic panels.

Q4: What are the disadvantages of soundproof foam?

Some potential disadvantages of using soundproof foam include:

  • Higher cost compared to traditional insulation materials

  • Professional installation is required for optimal results

  • May not provide complete soundproofing on its own

  • Potential off-gassing of volatile organic compounds (VOCs) during the curing process

Q5: Will soundproofing a wall work for noisy neighbours?

Soundproofing a wall can help reduce noise from neighbouring spaces, but its effectiveness depends on the type of soundproofing materials used and the quality of the installation. For best results, consider using a combination of soundproofing techniques, such as spray foam insulation, mass-loaded vinyl, or resilient channels.

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