Open-Cell Spray Foam vs. Closed-Cell Spray Foam

Whether you’re looking to reduce energy costs or keep your home or business at a comfortable temperature, spray foam insulation is the way to go. Once you’ve chosen to go with spray foam, it’s time to decide on which type of spray foam insulation will be best for your property. At MPI Foam, we install both open-cell and closed-cell spray foam depending on the goals you would like to achieve. Learn about the two types of spray foam insulation and the benefits of each here.



Open-cell foam is made up of cells that are slightly open and not completely enclosed. Because of this, open-cell foam is more flexible, soft, and vapor-permeable than closed-cell spray foam. Its soft, spongy, material allows bulk water to pass through–therefore minimizing the chance of condensation and mold growth.

When comparing open-cell to closed-cell insulation, open-cell foam uses significantly less material, making it a prime choice from a resource-use standpoint. It’s suitable for interior insulation and is the less costly option of the two. It’s designed to expand more than closed-cell spray foam, which means you typically only need (and can fit) one application.



Closed-cell foam is made of cells that are completely closed, making it a lot denser than open-cell foam at about 2 lb. per cubic foot (compared to the open-cell foam density of 0.5 lb. per cubic foot). Closed-cell foam is also a vapor retarder and uses a chemical blowing agent, versus the water blowing agent of open-cell. Unlike open-cell foam, closed-cell foam can be used on both interior and exterior surfaces, making it more versatile. It also can be used in both colder and warmer environments. Due to its unique features, we typically use closed-cell foam in places like wine cellars, against masonry basement foundation walls, and when sealing a crawl space.

Compared to open-cell insulation, closed-call has a higher R-value per inch (6-6.5 per inch) and can accommodate code requirements in narrow spaces. It also has a more rigid texture, adding wall-racking strength and impact resistance to your property. While it is the more expensive of the two, it’s a much more stable and rigid option that can be layered more due to its lack of expansion. 


Still looking to do more research? Learn more about open-cell spray foam and closed-cell spray foam to help make the best decision for you and your property.

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