A lap siding installation device for spacing and applying lap siding to a surface. Anchoring mechanisms are provided for releasably anchoring the device to a surface, and connection mechanisms are also provided to house the anchoring mechanisms. A first elongate member and a second elongate member extend from the connection mechanism in substantially the same direction. The second elongate member has a length greater than the first elongate member, and includes a protrusion with a ledge to receive and hold a piece of lap siding between the first and second elongate members. Methods are also included for spacing and applying lap siding to a surface.