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Difference Between Open Cell Foam And Closed Cell Foam

Feb. 02, 2023

Trying to decide which type of spray foam insulation you should use for your job? It's trickier than it looks - while both closed-cell and open-cell foam insulate homes, they do so in different ways. In this guide, we'll examine open cell foam versus closed cell foam and help you choose the best product for your project.


What is the difference between open cell foam and closed cell foam insulation?

Open cell foam and closed cell foam are two different types of spray foam insulation. They have different strengths and weaknesses, and one is not necessarily better than the other. It comes down to deciphering the advantages of open cell foam vs. closed cell foam and choosing the type that fits your needs.


Let's start by looking at the differences between open cell foam and closed cell foam.

EVA Open Cell Packing

 EVA Open Cell Packing


Spray insulation is called open cell or closed cell because of the differences between the small bubbles (vesicles) that make up the foam.


Open cell foam is filled with cells that are not fully encapsulated. In other words, the cells are intentionally open. This makes the foam a softer, more pliable material.


As the name implies, closed-cell foam consists of completely enclosed holes. The cells are pressed together so that air and moisture cannot get inside the foam. As a result, closed-cell foam is stiffer and more stable than open-cell foam.



Closed-cell foams are much denser than open-cell foams. Most open-cell foams have a density of about 0.5 pounds per cubic foot. Closed cell foam is more than three times as dense, with a density of 1.75 pounds per cubic foot or higher.



The R-value of a foam is its resistance to heat flow, or in other words, how well they insulate.

Closed-cell foams have a higher R-value than open-cell foams, typically about 6.0 per inch. but some closed-cell foams, such as Tiger Foam's E84 closed-cell formulation, have a higher rating, almost 7 per inch. this higher rating allows closed-cell foams to better retain heat in and out of the structure.

Open-cell foam has an R-value of about 3.5 per inch, which is significantly lower than closed-cell foam, which can limit the utility of open-cell insulation in extreme temperature conditions.

EVA Filter Foam With Open Cell

 EVA Filter Foam With Open Cell



From an application standpoint, this is one of the most important differences. Closed cell foam is designed to expand when sprayed to a thickness of approximately 1 in. Providing an r-value of 7 per inch, multiple applications can be applied to achieve higher total r-values. Open cell foam is designed to expand to a thickness of 3 inches, which means that only one application can be made on most standard walls.


What do all these terms and ratings actually mean?

At this point, you may still be trying to decipher which type of foam insulation is right for your project. Here is a quick summary of the strengths of open cell vs. closed cell foams and the best applications for each.


Benefits of closed cell foam Closed cell

foam is the best choice for robust insulation where space is an issue, as it can achieve up to 2x the R-value of standard in-wall open-cell foam. Its rigid properties also increase the structural integrity of the building and it is available in an E84 fire rated version. The closed cell also acts as a vapor barrier, so water and moisture are less likely to enter the room, and the foam itself is not subject to water damage.

Polyurethane Foam Tray

Polyurethane Foam Tray           

Benefits of open cell foam Open cell foam

One of the biggest benefits of open-cell foam is that it expands a lot after application, which means it can insulate hard-to-reach nooks and crannies. These types of areas are difficult to insulate with closed cell foam. Open-cell foam is great for soundproofing and can completely fill the area between double-ended studs in a single application.


Open cell foam is also more affordable than closed cell foam, but this foam will not insulate a home as well as closed cell foam, so it is not suitable for places with extreme weather temperatures.


So which type of insulation should I use?

Ultimately, it depends on the location of the home, what the insulation goals are, and of course how big the budget is. Need more help deciding between open cell or closed cell foam? Welcome to contact us.

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