Designed for repairing leaks in asphalt, metal, and composition roof surfaces. Used for waterproofing and on flashing where a heavy-duty product is required and as an emergency patching compound that provides good water resistance. Also useful for repairing leaks in shingles, concrete, gutters, around chimneys, and eaves. When reinforced with patching fabric or a suitable asphalt roofing membrane, this product provides a permanent patch of unusual strength over most surfaces. Applied with an ordinary trowel. For best results, apply as follows: Small holes: Under 1" place material over and around hole from 3/8" to 1/2" thick, spread down to a feather edge. Large holes: A piece of patching fabric or suitable asphalt roofing membrane is first nailed over larger holes. Nails should be 2" to 2-1/2" apart. Trowel plastic roof cement under and over the patch, spread down to a feather edge. Loose nails, laps, and seams: Drive in loose nails. Trowel plastic roof cement to a thickness of 3/8" to 1/2" over all loose laps and seams, spread down to a feather edge. Apply at a rate of 12.5 sq. ft. per gallon or 1/4" to 1/8" in thickness. Meets performance requirement ASTM D2822 and Federal Specifications SS-C 153C, Type 1. Do not use on shingle roofs. Do not apply over damp or wet surfaces.