VARIABLE THICKNESS SHINGLE

摘要

A method of manufacturing roofing shingles comprises the steps of: coating a continuously supplied shingle mat with roofing asphalt to make an asphalt-coated sheet, the asphalt-coated sheet having at least one prime portion and at least one headlap portion, varying the thickness of the asphalt-coated sheet such that the at least one prime portion of the asphalt-coated sheet has a first thickness and the headlap portion has a second thickness, the thickness of the asphalt-coated sheet being varied by passing the asphalt-coated sheet through a secondary coater to form a granule-covered sheet, and cutting the granule-covered sheet into shingles.