Clear Roof Sealer Smartseal roof sealer creates a water repellent barrier and protects against re-growth of moss and algae. The roof tile sealer is a high quality, clear, solvent free acrylic impregnating roof sealer for concrete, clay or slate tile roofs. Once applied, the roof sealer will alter the chemical structure of any roof tile and provide an excellent water repellent surface. The clear roof sealer will also greatly restrict the growth of algae, lichen and moss to the surface of the tile.