Abstract: A siding application tool and a method for installing siding using the tool is described. The tool includes an overlap portion 14 having upper and lower ends, an L-shaped hook portion 10 with an upper bearing surface 12a that forms a generally right-angle hook with the overlap portion, an L-shaped retainer portion 16 with a lower bearing surface 12b that forms a generally right-angle retainer with the overlap portion, and a plate member 18, which may optionally include a slot 20 configured to accept the tongue of a tape measure.