PROVA BOARD® PLUS is a lightweight tile backer that is quick and easy to install over wood stud framing. The 100% waterproof XPS core prevents mold growth and is resistant to vapor pressure. Use PROVA BOARD® PLUS with necessary accessories (PROVA FASTENERS® and PROVA-SEAL™) to guarantee a watertight installation on walls, countertops, showers and tub surrounds.