The air barrier is one of the most significant items on any building exterior. The installation and process should reflect the importance of the system and its intricate installation and integration of non-air barrier system components, such as waterproofing, structural elements, windows, and roofing systems.
The importance of infection control and the impact of operating conditions on the built environment have taken renewed focus in the wake of the COVID-19 pandemic. As a part of the ongoing response, industry organizations, such as the American Society of Heating and Refrigerating and Air-conditioning Engineers (ASHRAE), have released updated considerations for design and construction professionals, including airflow strategies and temperature and humidity controls, as well as ventilation and pressurization.
Metal can be formed into several shapes, sizes, colors, and textures to meet almost any aesthetic. If specified correctly, the assembly will last for the life of the building with very few issues. Three broad categories—composites, insulated metal panels (IMPs), and single-skin—of metal rainscreens are widely used.
The term rainscreen refers to a building system fulfilling one of the main functions of an exterior wall—to screen out rain and keep a wall dry. While at one time that system would have encompassed moisture control alone, the complexity of exterior wall assemblies now requires a more integrated approach. Multicladding aesthetics with the benefit of continuous control layers are achievable with new rainscreen system designs.
With the variety of cladding materials available today, and designers’ penchants to combine styles and textures, it is essential to specify building envelope controls that are compatible with multiple cladding types. This balancing act between aesthetic preferences and air and moisture management is where gypsum-integrated water-resistive barrier-air barrier (WRB-AB) sheathings shine.