Main roof: - remove existing roof down to wood decking. Nail 30lb base sheet to remainder of roof. Shingle with a gaf eik hd lifetime timberline demensional shingles as per manufactures specifications. (weathered wood cedar, timberline shape). Work to be done in accordance with philadelphia historical commissions guidelines and approved plan. Install new roof cover as per manufacturers specifications. . New roof coverings shall not be installed without first removing all existing layers when the roof has two or more applications of any type of roof covering. Submit roof certification to inspector for final inspection.