HYDRO-BLOK wallboard products are built with the same high quality construction as the rest of our foam products with a 100% waterproof XPS foam core, covered by fibreglass mesh and then coated in a modified cement coating to provide superior strength and an excellent bonding surface for your tile, stone, glass or mosaics. All wallboards can be easily cut with a utility knife, hand saw or small circular saw. They can be custom cut and can also be cut to bend around inside or outside corners.