Abstract: A method of forming a continuous joint between and along the upwardly projecting side walls of a pair of channel-shaped panels each having a central web with first and second side edges. The first side wall of one panel initially comprises first and second vertical legs and a nail strip connected to the bottom of said first vertical leg. The opposing side wall of the other panel is a vertical leg with an upper, inverted U-shaped channel. The method comprises: a) locating a first panel with said nail strip to overlay a roof support surface, b) driving fasteners through the nail strip into the roof support surface, c) placing the second side wall of a second roof panel into engagement with the first side wall wherein the inverted U-shaped channel is interfitted over the first side wall, and d) deforming the interfitted side walls to form a deformed standing seam.