Abstract: Disclosed is a simple, easy and efficient metal roof curb system and method for attachment which includes a generally rectangular curb assembly, the edges of which have inwardly facing upper and lower flanges to facilitate secure and waterproof attachment to the roof panels. One end of the curb assembly is designed for attachment at the low or downwardly facing side of the roof, and the opposite end is designed to be attached to the high or upwardly facing side of the roof. The low end of the assembly includes a set of recesses designed for alignment with and attachment to the ribs of the metal roof. The high end includes no such recesses, but is instead designed for direct attachment to the flattened roof panels, the ribs of which are cut and plugged. A pre-attached Z-shaped water diverter is included on the high side, the assembly calling for a water diverting cricket to be installed on the high side in the field.