An internal underlay for ceramic tile finishes that helps protect against movement that occurs naturally in timber, particleboard and plywood substrates. Able to be used on top of these substrates and under ceramic tiles, in residential wet and dry areas. Pre-marked nailing pattern to reduce time working out where to nail. Larger sheet size is ideal for bigger bathrooms and large floor areas. Pre-sealed sheets increases cement-based tile adhesive working time by 50%. Can be used in internal wet and dry areas when installed and maintained correctly. Minimises tile movement to help reduce the potential for tile cracking.