Exterior Gypsum Sheathing for High Performance Building
In 1986, fiberglass-faced gypsum sheathing was introduced to the marketplace to help with scheduling issues. Especially with EIFS, exposed paper-faced sheathing would either delaminate or show the growth of mold, necessitating the need to replace the sheathing prior to installing the cladding. In contrast, fiberglass-faced products could be exposed for extended periods. Though it grew in popularity over the years, in 2006 it became a go-to product for high-performance exterior wall assemblies.
The 2006 International Building Code called for the addition of a weather resistive barrier to address air and moisture issues over the surface of sheathing. (“An approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls.”) To comply, architects, contractors and subcontractors needed a product that would minimize air leakage and moisture intrusion into the wall cavity. Fiberglass-faced gypsum sheathing, which provides a stable base on which to apply the WRB, became an even greater option (it was always a growing option; with the code changes, it became an even more compelling option). Composed of an inorganic, moisture-resistant gypsum core and fiberglass facers, it exhibits low thermal and hydrometric expansion and is ideal to take on the elements and maintain dimensional stability. It weathers well during construction and is not moisture sensitive.