Ever since I moved into my charming yet somewhat aged home, I couldn’t help but notice the irritating noise that seemed to seep through the walls. It made me wonder if there was a simple solution that wouldn’t involve tearing everything down.

Then, I discovered soundproofing spray foam for existing walls – a game-changer, to say the least. This innovative product not only reduced noise levels but also enhanced the overall insulation of my home. I was ecstatic to find a cost-effective and efficient way to make my living space more peaceful.

As someone who’s experienced the benefits of this fantastic product first-hand, I feel it’s my duty to share my insights with you. Through my journey, I have learned the ins and outs of soundproofing with spray foam, and I’m here to guide you every step of the way.

In this blog post, I will be sharing my problem-solving tips and recommendations to help you achieve the serene home you deserve. Join me as we explore the wonders of soundproofing spray foam for existing walls, and trust me, you won’t be disappointed.

📊Top 5 Soundproofing Spray Foam For Existing Walls

RankProductR-valueMy Rating
1.GREAT STUFF PRO Insulation Sealant4.55/5
2.Akfix Thermcoat Spray Foam Insulation5.764.8
3.Loctite Tite Insulating Foam5.765
4.Vega Bond Purplecoat Insulation Spray Foam5.664.8
5.Seal Spray Foam High-Performance Closed Cell4.374.9

🤔How Does Soundproof Foam Work?

Soundproof foam, also known as acoustic foam or sound-absorbing foam, works by absorbing sound waves that travel through the air. When sound waves hit the foam, the waves cause the air particles within the foam to vibrate, which converts the sound energy into heat energy. This conversion of energy reduces the amount of sound that is reflected back into the room or transmitted to other areas.

soundproof spray foam for wall

The effectiveness of soundproof foam depends on its design and placement within a room. The foam is typically made up of open-celled foam, which creates a porous surface that traps sound waves as they enter the material.

The foam’s shape and structure also play a role in its ability to absorb sound. Some foam designs are engineered to diffuse sound waves, redirecting them in different directions to reduce their intensity.

Types of Soundproofing Spray Foam

The two main types of spray foam insulation are open-cell and closed-cell. Both types can be used for soundproofing, but they differ in their density, cost, and installation process.

Open-cell spray foam

Open-cell spray foam insulation is less dense than closed-cell foam, making it more flexible and easier to install. It is also less expensive than closed-cell foam.


Open-cell foam is made up of cells that are not completely sealed, allowing air to flow through the material.

This makes it a good choice for sound absorption, as it can trap sound waves within the material. However, it is not as effective at blocking sound transmission as closed-cell foam.

Closed-cell spray foam

Closed-cell spray foam insulation is denser and more rigid than open-cell foam. It has a higher insulation value and is better at blocking sound transmission.

This makes it an effective choice for soundproofing walls and ceilings. Closed-cell foam is also more expensive than open-cell foam due to its higher density and insulating properties.


The cost and installation process for each type of spray foam insulation can vary depending on the size and complexity of the project.

soundproof spray foam

In general, open-cell foam is less expensive and easier to install than closed-cell foam. Open-cell foam can be installed with a spray gun, which allows for easy application and can cover large areas quickly.

Closed-cell foam, on the other hand, requires a professional installer with specialized equipment to apply the foam correctly. The installation process for closed-cell foam can be more time-consuming and expensive than for open-cell foam.

⚙️Soundproofing existing walls with spray foam insulation: How Easy?

Soundproofing existing walls with spray foam insulation involves injecting foam insulation into the wall cavity to create a barrier that prevents sound transmission. Here is a general overview of the process:

  1. Inspect the existing walls: Before starting the installation process, it’s important to inspect the walls to identify any leaks, gaps or holes. These will need to be sealed before the insulation is installed.
  2. Drill access holes: Access holes are drilled into the walls at the top and bottom of each stud bay. These holes are typically 2 to 3 inches in diameter and spaced about 16 inches apart.
  3. Inject the foam insulation: Using a special spray gun, the foam insulation is injected into the wall cavity through the access holes. The foam expands to fill the cavity and create an airtight seal.
  4. Close the access holes: Once the foam has been injected, the access holes are closed using a sealant.

💡Soundproofing with spray foam insulation Benefits

Soundproofing with spray foam insulation provides a range of benefits, including improved comfort, energy efficiency, and noise reduction.

Improved Comfort: Soundproofing with spray foam insulation can improve the comfort level of your home or building by reducing unwanted noise from outside or other rooms. This can lead to a more peaceful and relaxing living environment.

Energy Efficiency: Spray foam insulation is also an effective thermal insulator, which can help reduce energy costs by keeping the temperature inside the building more stable. The insulation helps to prevent heat loss during the winter and heat gain during the summer.

Noise Reduction: Soundproofing with spray foam insulation can significantly reduce the amount of noise that enters or leaves a room, providing a more private and quiet space.

Increased Property Value: Soundproofing with spray foam insulation can increase the value of your property by making it more appealing to potential buyers or renters. Soundproofing can be particularly attractive to those who live in noisy areas or who need a quiet space for work or relaxation.

Better Quality of Life: Soundproofing with spray foam insulation can lead to a better quality of life by reducing stress, improving sleep, and increasing productivity.

🧾How to Choose the Best Soundproofing Spray Foam for Existing Walls?

Choosing the best soundproofing spray foam for existing walls can be a bit challenging, but by considering a few key factors, you can make an informed decision. Here’s a step-by-step guide to help you find the right product:

Determine your needs

Assess the level of noise you’re trying to block, and identify the type of sound (airborne or impact) that’s causing the problem. This will help you determine the right spray foam product to use.

Types of spray foams

There are two main types of spray foam insulation – open-cell and closed-cell. Open-cell foam is softer and more flexible, making it better at absorbing airborne noise. Closed-cell foam is denser and more rigid, making it more effective at blocking both airborne and impact noise.

Consider the R-value

The R-value of a spray foam insulation indicates its resistance to heat flow. A higher R-value means better-insulating properties, which also translates to better soundproofing. Look for a product with a high R-value for better noise reduction.

Check for Soundproofing Ratings

Soundproofing materials are rated by their sound transmission class (STC) and impact insulation class (IIC). A higher STC and IIC rating indicates better soundproofing performance. Choose a spray foam with a high STC and IIC rating to ensure maximum noise reduction.

Choose a reputable brand

Opt for a well-known and reputable brand that has a history of producing high-quality soundproofing products. This will help ensure you’re getting a reliable and effective product.

Ensure proper installation

Spray foam insulation must be installed correctly to maximize its soundproofing potential. Hiring a professional installer can ensure that the foam is applied evenly and properly, leading to better results.

⭐Best Soundproofing Spray Foam For Existing Walls

Best Overall

GREAT STUFF PRO Insulation Sealant

GREAT STUFF PRO Insulation Sealant
My Rating:

The GREAT STUFF PRO Gaps and Cracks Foam Insulation Sealant is an excellent product that delivers on its promise to fill gaps and cracks around the home, reduce energy loss, and increase energy efficiency.

The product is easy to use, provides excellent value, and comes with an application gun that allows for precise control of the foam flow.

However, the gun may be challenging to use near the ceiling or roof rafters, and the foam may not stick to the walls initially. Overall, this product is highly recommended for anyone looking to improve their home’s energy efficiency.

As a homeowner who’s always looking for ways to improve energy efficiency and cut down on utility bills, I was excited to try the GREAT STUFF PRO Gaps and Cracks Foam Insulation Sealant. The product promised to fill gaps and cracks around my home and reduce energy loss, and I’m happy to say that it delivered on its promise.

I used the sealant to air-seal my 1980s house, and I was impressed with the results. I managed to insulate around all vents, ceiling penetrations, wall headers, plumbing penetrations, and HVAC vents with just a few cans. The fact that it’s fire block rated made it perfect for use around electrical boxes too.

The application gun provided in the kit worked exceptionally well. It allowed for precise control of the foam flow, ensuring that it didn’t come out uncontrollably like with regular spray cans. Although it doesn’t spray upside down, it’s a minor inconvenience considering the overall quality of the product.

One issue I encountered initially was the foam not sticking to the walls properly. To solve this, I heated the cans near a small heater for about 45 minutes, which increased the pressure and allowed the foam to adhere better. I found this tip to be helpful when using smaller canisters like the ones in this kit.

I had no problem with clogging, and the cleaner included in the kit kept the gun in great condition. It’s essential to follow the instructions when changing cans to prevent any issues.

The only drawback I experienced was that the gun worked well when applying foam near the floor and walls, but it was challenging to use near the ceiling or roof rafters. The canister’s size prevented close access, and the straw attachment didn’t work as expected, causing a bit of a mess.

Despite this minor issue, I found the GREAT STUFF PRO Gaps and Cracks Foam Insulation Sealant to be an excellent value. The foam canisters contained a generous amount of foam, and the kit provided everything I needed for the job. The insulation made a noticeable difference in my home’s energy efficiency, and I couldn’t be happier with the results.

In conclusion, I would 100% recommend the GREAT STUFF PRO Gaps and Cracks Foam Insulation Sealant to anyone looking to improve their home’s energy efficiency. It’s easy to use, offers great value, and delivers on its promise. Just be prepared for some minor challenges when applying near the ceiling or roof rafters, and don’t forget to wear old clothes when working with the product.

Best Value

Akfix Thermcoat Spray Foam Insulation

My Rating:

Akfix Thermcoat Spray Foam Insulation is a polyurethane-based foam that provides heat and sound insulation.

It has a quick curing time and two nozzles and can be used on various surfaces. While some users have concerns about the foam’s density and expansion, it effectively sealed the crawl space and attic.

Overall, it’s easy to use, versatile, and suitable for various applications.

Akfix Thermcoat Spray Foam Insulation is a polyurethane-based spray foam designed for heat and sound insulation. It’s advertised as easy to use, with two different nozzles for vertical and ceiling applications, and suitable for various surfaces, including drywall, wood, concrete, and more.

One of the things that drew me to Akfix Thermcoat was the quick curing time. I didn’t have to wait too long for the foam to bond, and I found that gaps and uneven surfaces didn’t cause too much of an issue, as long as I waited 24 hours for a full cure.

I first tried Akfix Thermcoat on my shed’s walls and roof. After a bit of practice, I got the hang of the application speed and overlap. However, I noticed that the foam didn’t expand as much as I expected, so I had to apply multiple coats to fill the 2×4 and 2×6 voids. Some cans also didn’t spray with the same consistency as others, which could be due to temperature or other factors.

One thing that concerned me was the density of the foam. I compared it to a well-known brand, “Great Stuff,” and found that the Akfix foam was significantly less dense. This left me questioning if it truly is a closed-cell foam, as advertised. The foam remained somewhat soft even after five days, which was disappointing.

That being said, I also used Akfix Thermcoat in my crawl space and attic, where it seemed to perform better. The foam provided a uniform, thick first coat when I sprayed it on my rim joist. I didn’t need to use water activation, and I found the spray easy to control, resulting in minimal waste. The foam effectively sealed up the crawl space, and I noticed an improvement in the area’s smell.

So, while Akfix Thermcoat Spray Foam Insulation may not be perfect, it does have its advantages. It’s easy to use, bonds quickly and is versatile enough for various applications. However, the inconsistent density and expansion might be a deal-breaker for some.

Best for Budget

Loctite Tite Insulating Foam

My Rating:

I find it easy to use and paintable. However, the foam did not expand enough and had issues with separation on aluminum surfaces.

The product had inconsistent spraying, and the foam’s density was not as high as expected, remaining soft even after several days.

My first experience with Loctite Tite Spray Foam Insulation was on the shed walls. I was pleasantly surprised by how evenly it sprayed compared to other brands. The product was paintable, and the two nozzle options made application easier.

Nozzle A worked well for vertical applications, while nozzle B was perfect for ceiling applications. In terms of insulation value, the closed-cell foam has an R-value of 5.76, which is decent.

The product cures relatively quickly, which is a plus. However, I found that it didn’t expand as much as I would have liked. This meant that I needed to apply multiple coats to fill the 2×4 or 2×6 voids in my shed’s roof. Despite this, the foam adhered well to the various surfaces I used it on, including wood, concrete, brick, and metal.

I did encounter a few issues, such as the foam separating and leaving bare spots on the aluminum ceiling of my storage trailer. This required multiple applications and ultimately led to some wasted product. It’s also worth mentioning that some cans didn’t spray as consistently as others, which could be due to temperature or other factors.

Based on the reviews I’ve seen, there is some debate over whether this is a closed-cell or open-cell product.

From my experience, the density of the foam wasn’t as high as I would expect from a closed cell foam. I found that the foam remained quite soft even after several days, which could be a concern for some users.

R-value of 5.66

Vega Bond Purplecoat Insulation Spray Foam

My Rating:

Vega Bond Purplecoat Insulation Spray Foam is an alternative to traditional building insulations that can be applied to various surfaces, including wood, brick, stone, concrete, metal, drywall, and glass.

The product has an R-value of 5.66 per inch and a thermal insulation value of 0.025 W/(m.K). The comprehensive kit that comes with the product includes foam, a gun, a cleaner, a paper suit, gloves, a mask, and goggles. However, the product requires careful temperature control during application and may result in a messy process.

Vega Bond Purplecoat Insulation Spray Foam is an alternative to traditional building insulations such as fiberglass batts, blow-in, insulation boards, glass wool, and rock wool. It boasts an R-value of 5.66 per inch and a thermal insulation value of 0.025 W/(m.K). This spray foam can be applied to a variety of surfaces, including wood, brick, stone, concrete, metal, drywall, glass, and more.

One of the standout features of this product is the comprehensive kit it comes with. It includes the foam, gun, cleaner, paper suit, gloves, mask, and goggles – everything you need to get started. The sprayer tips are quite pliable, which I found to make the application process smoother.

When applying the foam, it’s essential to keep the cans at or above 68 degrees Fahrenheit. I learned this the hard way when I noticed a difference in performance as the temperature in my sunroom dropped from 72 to 65 degrees. The foam didn’t accumulate as well as it should have, resulting in a splotchy texture with holes in it. This might have been due to my application technique or the temperature change, but it’s something to keep in mind.

Another tip I’d like to share is to change the sprayer tips with each new can. I found that this made the application smoother and more consistent. Additionally, expect to use about three times the board feet (BF) coverage you’re aiming for when working on a project. This is because most of us DIYers might not have the most consistent spraying technique, and the foam tends to spray out quite quickly.

It’s worth mentioning that the Vega Bond Purplecoat Insulation Spray Foam can be quite messy. I suggest taping off anything you don’t want the foam to get on, even if it’s ten feet away. Moreover, be prepared to layer your applications and give the foam some time to cure before reapplying.

R-value of 4.37

Seal Spray Foam High-Performance Closed Cell

My Rating:

Seal Spray Foam is a compact insulation product that is easy to use and provides an impressive R-value of 4.37 per 1” thick layer.

It sticks well to surfaces, expands to fill gaps and is ideal for smaller insulation projects.

While it may take some practice to control the spray, it is a valuable addition to any DIYer’s toolkit.

The Seal Spray Foam comes in a 27.4oz can that covers approximately 25 board feet (1 board foot = 12″ x 12″ x 1″ thick). It has an R-value of 4.37 per 1” thick layer, which is quite impressive for such a small package. The product is applied by attaching the included spray nozzles to the can, making it simple and easy to use. The compact form factor also means that there’s no large tank disposal, and you can take it anywhere.

I used the Seal Spray Foam to insulate a shed in my backyard. I was amazed at how well it stuck to the surfaces and expanded to fill the gaps. I made the mistake of using a cheaper product on my second attempt, only to realize the difference in quality. The cheaper product didn’t stick or expand as well and left me with an unsatisfactory result. I learned my lesson and went back to the Seal Spray Foam for the remaining areas.

I found that controlling the speed and width of the spray took some practice, and I agree with other users that including a simple instruction card would have been helpful. Once I got the hang of it, though, I was able to achieve decent coverage with just two cans.

I experienced some difficulty when trying to spray the ceiling, as the can had to be held in a precise position to work correctly. This led to a considerable amount of product loss as foam fell to the floor.

Despite these challenges, I believe that Seal Spray Foam High-Performance Closed Cell Insulating Foam is an excellent product for smaller insulation projects where precision and ease of use are priorities. It’s compact size and strong adhesion make it a valuable addition to any DIYer’s toolkit.

💭What are the alternatives to acoustic spray foam?

There are several alternatives to acoustic spray foam that can be used for soundproofing and reducing noise in various spaces. Here are some popular options:

Mass Loaded Vinyl (MLV): MLV is a dense, flexible material that helps block sound transmission. It can be applied to walls, ceilings, and floors to improve sound isolation between rooms.

Fiberglass Insulation: Fiberglass insulation is a common material used for thermal insulation, but it can also provide soundproofing benefits. Installing fiberglass insulation between wall studs, floor joists, or ceiling rafters can help reduce sound transmission.

Rockwool Insulation: Made from mineral wool, rock wool insulation is denser than fiberglass insulation and provides excellent sound absorption and sound-blocking properties. It can be used in walls, ceilings, and floors for soundproofing purposes.

Green Glue: Green Glue is a viscoelastic damping compound that can be applied between layers of drywall, plywood, or other rigid building materials. It converts sound energy into heat, helping to reduce sound transmission between rooms.

Soundproof Drywall: Also known as acoustic drywall, soundproof drywall is a specialized type of drywall designed to block sound transmission. It’s typically denser and heavier than regular drywall and can be used to construct walls, ceilings, and partitions.

Resilient Channels: These are metal channels that can be installed between drywall and the framing structure to create a small gap, which helps to decouple the wall layers and reduce sound transmission.

Acoustic Panels: Made from various materials such as foam, fabric, or wood, acoustic panels can be mounted on walls and ceilings to absorb sound and reduce reverberation in a room.

Soundproof Curtains: Heavy, dense curtains designed specifically for soundproofing can help block outside noise and improve the acoustics of a room. They can be an effective solution for windows or as a movable partition between rooms.

Before You Get Going

Remember, the key to being smart when it comes to choosing the best spray foam for your soundproofing project is checking for the right features and soundproofing ratings that come with each product.

Choose soundproofing spray foam kits with high STC ratings for the best soundproofing results. Also, consider the kit inclusions when buying a spray foam kit to avoid needing to spend more on separate items needed for your project.

Robert Castelao
Robert Castelao

Robert is an electronic engineer with more than five years of experience with a solid affinity for helping people reduce noise. He writes about these silent home appliances and easy soundproofing measures to help everyone avoid the negative effect of extended exposure to high noise levels.

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