Building owners with gravel roofs have a systematic maintenance answer with Heavy Duty Gravel Roof Preservative. A black, liquid solvent base asphalt product, it penetrates age hardened flood coatings and exposed roofing felts, softens them, makes them more flexible and improves their strength and weathering characteristics. As it penetrates, it seal hairline cracks and forms a new weather surface with increased resistance to moisture, weathering and oxidation. Gravel is redistributed after installing the preservative.