New testing confirms that USG sheathing supports 24-inch on center EIFS construction
USG's Fiberock Brand Sheathing with Aqua-Tough now enables specifiers and contractors to design and build EIFS assemblies using 24-inch on center construction, without compromising building safety or structural integrity.
Historically, the EIFS industry has used 16-inch OC framing to meet wind load capacity and deflection performance requirements. As confirmed by recent independent testing, Fiberock is the first substrate that delivers the needed flexural strength and nail pull resistance to allow for 24-inch OC construction.
The 1/2-inch thick USG sheathing panels, made from a patented gypsum/cellulose fiber formulation, deliver wind loads up to 32 psf before surpassing the accepted EIFS deflection standard of L/240 when installed 24 inches OC with fasteners attached 8 inches OC. When fasteners are attached 12 inches OC, design wind load for Fiberock assembly is reduced only slightly to 31 psf before surpassing L/240 deflection. This deflection criterion meets the requirements for most one- and two-story commercial EIFS projects.
"Going to 24-inch OC construction can significantly reduce EIF system installation costs," said Ron Bruggeman, Fiberock marketing manager for USG. "Specifiers are able to offer reduced project costs by designing for 24-inch OC, and contractors have the potential to increase profit margins through savings on labor time, framing materials and fasteners when using a 12-inch OC screw spacing."