Closed Cell vs Open Cell Foam
In understanding the performance of different types of foam materials, a very important consideration is whether a specified foam is open cell (open cell walls that allow water and moisture to pass through), and closed cell foam (closed cell walls that do not allow water or moisture to pass through).
Generally open cell foams typically are used where moisture is not a consideration, and a quicker compression recovery is desired. Closed cell foams are specified where moisture or water is a consideration or where the closed cell foam can be compressed in application to perform a water barrier as in a gasket application.