Asphalt roofing needs the proper amount of nails for Timberline and architectural shingles to be installed correctly. GAF Timberline 30 year material. When installing shingles it is important that you use the proper roofing nails. The standard size for shingle application is 1 1/4 inch in length. When nailing the shingle it is best to follow manufacturers specifications to the tee. Any deviation from these specifications can result in a void warranty. Galvanized nails are to be used for asphalt shingles and copper nails are to be used for the installation of slate and tile.Your Atlanta roofing company should use nail guns for the installation of your new roof system.