A smooth and stable internal underlay for ceramic tile finishes, James Hardie™ Ceramic Tile Underlay helps protect tiles against cracking caused by the movement that occurs naturally in timber, particle board and plywood substrates. Suitable for wet and dry area floors, the pre-sealed coating guards against moisture, helps tile adhesion and slows the glue adhesion time giving tilers more time to achieve a perfect result. Easily installed, it can be quickly gun-nailed with an underlay gun using the pre-marked nailing pattern on the sheet.