How does closed-cell spray foam provide moisture protection, yet still breathe?
Unlike cellulose and fiberglass materials, closed-cell foam is impervious to water absorption and wicking. Yet, like Gortex fabric, the closed-cell structure allows the passage of water vapor (high energy particles) to allow your home envelope to breathe. Liquid water has much larger particles and is unable to pass into or through a closed-cell foam barrier.
