Understanding Closed Cell Spray Foam

Understanding Closed Cell Spray Foam


Closed-cell spray foam (also known as 2-pound foam) has a density of about 2 pounds per cubic foot and an R-value of 6 to 6.5 per inch. Because it is a denser material, closed-cell spray foam not only provides a vapor and water barrier to a home or structure but also adds additional structural strength. Closed-cell spray foam typically costs more than open-cell spray foam.

Because the cells in closed foam have their own structure and don’t share any structure with other cells, the foam has a higher plastic content and less air.  The industry standard for spray foam to qualify as “closed cell” is that greater than 90% of the cells are closed.

Spray Foam: Open-Cell vs. Closed-Cell | Johns Manville

Advantages of Closed Cell Spray Foam

What is Closed Cell Foam, What is Open Cell Foam, Closed Cell Insulation, Closed  Cell Foam,

While open-cell and closed-cell foams are both polyurethane-based, the main difference between the two is that closed-cell foam is:

  • Denser
    • Two and a half inches of closed-cell foam have a permeance of 0.8 per m.  Less water/air can pass through a closed-cell foam
  • Heavier
    • Because closed-cell foam is denser, it provides added wall/structural strength.   One place that open-cell would be a better fit could be an attic or ceiling, due to weight.
  • Provides better insulation and water barrier
    • Although it is typically more material (and therefore more costly) than open-cell spray foam, closed-cell foam is less permeable and more water-resistant.  This can prevent unwanted mold/moisture in hidden places.

Price Consideration

Although there are many advantages of having a closed spray foam insulation, the price is a drawback simply because there are more materials needed to create the denser insulation.  Closed-cell foam is more expensive per “R,”  so one can expect an R-10 of closed-cell to be costlier than an R-10 of open-cell.   There is more plastic used in closed-cell, and the chemicals used for a blowing agent in closed-cell foam is much more expensive than the water used in open-cell foam.  However, there are benefits of increased effectiveness and strength.  

Looking for a Spray Foam Supplier?

 The specialists at ArmorThane are a good place to go if you are looking for a foam supplier.

1 Response

  1. I really appreciate you stating that closed cell spray foam can provide better insulation and protection from moisture. Moisture is notorious for giving homeowners some trouble, so I want to prevent it as much as possible since our area has some really rainy weather. If I can find a wall insulation contractor in the area, I’ll make sure I ask for closed-cell spray foam.

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