When building exterior walls with stone, stucco, brick, cedar, EIFS, or fiber cement siding, it is important to use an effective rain-screen system that will provide a means for drainage and ventilation. Moisture will find its way into these wall systems by way of cracked mortar joints, gaps or cracks in the surface of the material. Natural absorption of the wood or fiber cement also needs to be considered. Once this moisture penetrates the outer surface of the wall, it becomes trapped in the wall system with no way to escape, creating the perfect environment for toxic mold growth and possible structural failure. Mortairvent is a drainage and ventilation system specifically designed for use with most exterior siding materials.