USG Durock Tape (50 ft. per roll) Strong, long-lasting glass-fiber tape that provides high-quality joint reinforcement indoors and out. USG Durock™ Brand Tile Backer Tape is specifically engineered to provide a strong, long-lasting hold for interior and exterior cement board joints, corners and abutments. Made from alkali-resistant, polymer-coated glass-fiber mesh, the tape is crack-resistant and can ensure the job gets done right the first time. USG Durock™ Brand Tile Backer Tape can be used for interior and exterior joint reinforcement projects and comes in two different sizes depending on the application. Alkali-resistant glass-fiber construction Reinforces joints and corners of cement board in exterior substrate applications and interior tile or thin-brick applications Reinforces joints and corners of USG Fiberock® Panels in interior tile applications Sizes for interior (2-inch wide) and exterior (4-inch wide) joint reinforcement