Gallon Rubber Roof Cement 6146-9-34 by Gardner Gibson Black Jack Pro Series Power Seal #11, Rubberized Roof Cement, Thick Trowel/Flashing Grade, Stops Roof Leaks, Use In Wet Or Dry Conditions, Use For Repair Or New Construction. Power-Seal #11 Is An All-Weather, Asphalt Based Patching Compound Designed To Repair Cracks, Seams & Holes In Roofing Materials, Works Great In Setting Flashings, Drip Edges & Roofing Material Edges, Seals Damaged Areas & Gives Layer Of Waterproof Protection, Use On Roofs Around