Patent ID: 8309169

Claim:
A method of manufacturing roofing shingles comprising 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 by passing the asphalt-coated sheet through compression rollers configured to compress 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, different from the first thickness wherein compressing the asphalt-coated sheet forms a formed sheet; passing the formed sheet under a film applicator configured to apply a film to the at least one headlap portion wherein application of the film forms a filmed sheet; applying granules onto the filmed sheet such that the granules do not adhere to the at least one headlap portion, wherein application of the granules forms a granule-covered sheet; and cutting the granule-covered sheet into shingles.