FIBEROCK® Brand Panels are manufactured from a unique combination of gypsum and cellulose that provides superior strength. These durable, abuse-resistant panels can be installed and finished using basic drywall techniques. FIBEROCK products that incorporate USG’s patented AQUA-TOUGH™ formulation also offer integral moisture- and mold-resistance. Its uniform composition won’t weaken if the surface is penetrated by moisture. Used in numerous applications, FIBEROCK Brand products include interior, abuse-resistant panels, tile backer board, underlayment and sheathing.