What is the Difference between Open-Cell and
Closed-Cell Polyurethane Foams?
When it comes time to actually put the foam product in your home or commercial building structure, you must identify whether you will use open cell foam or closed cell foam. This makes a big difference in cost, application methods, and performance. With the open-cell vs. closed-cell issue, there are two major factors to understand and consider. The first is the nature of the foam. It is either open-cell foam, where the tiny cells of the foam are not completely closed. They are broken and air fills all of the “open” space inside the material. This makes the foam weaker or softer feeling than closed-cell foam. Closed-cell foam differs in that all of its tiny foam cells are closed and packed together. They are filled with a gas that helps the foam rise and expand and become a greater insulator. These cells can be formulated to obtain many characteristics, the most common being size and density. Density is measured by weighing one solid cubic foot of foam material. Open cell foams typically weigh in at 0.4 to 0..5 lb./cu. ft. Closed cell foam for insulation applications range in density from 1.7 lb./cu. ft. to 2.0 lb./cu. ft. The higher the density the foam, the heavier, or stronger it becomes.The advantages of closed-cell foam compared to open-cell foam include its strength, higher R-value, and its greater resistance to the leakage of air or water vapor. The disadvantage of the closed-cell foam is that it is denser, requires more material, and therefore, is more expensive. Both types of foam are commonly used in most building applications, and the choice can depend on many of the factors discussed above.
