Patches holes and cracks on WET surfaces, even in a driving rain or under water. Creates a tight seal around chimneys, vents, skylights, and flashings. May be used in wet, dry, hot or cold weather. Made from heavy-bodied refined asphalt, organic fibers, petroleum solvent, and a water displacement agent. Covers 12.5 sq. ft. per gallon at a thickness of 1/8".Meets or exceeds all requirements of ASTM Specification D-4586, Type I except for high temperature sag.