BamCore’s bamboo-based hollow Prime Wall System delivers a water vapor transmission rate that matches the range of rates found in commonly used house wraps. Recent independent tests documented that the bamboo-based panel component of BamCore’s Prime Wall System offers a Water Vapor Transmission or permanence rate that is three to six times greater than conventional wood products like OSB and plywood. Modern low-rise construction techniques regularly rely on a variety of wraps to keep air and liquid water from penetrating building walls, while at the same time allowing water vapor to breathe out of the wall. The movement of water vapor across a wall surface allows the entire wall and cavity to dry out if it gets wet, thereby preventing mold. Unfortunately, the “perm” rate of commonly used 7/16” OSB is very low compared to building wraps and can defeat the vapor permanence role of the wrap. In replicated tests conducted by ISO/IEC accredited RADCO Listing and Testing Division in Long Beach, CA, BamCore’s exterior Prime Wall Panels received an average perm rating of 6. This is the beginning of the perm range for building wraps like Grade D Building Paper, #15 Felt and Perforated Wraps. Other wraps start even higher.