Patent ID: 8307603

Claim:
A method for constructing a stair unit, comprising: determining a number of treads and a rise and run of each tread; determining a first angle (“horizontal angle”), a second angle (“vertical angle”) and a hypotenuse of a right template triangle, the template triangle having a first side (“horizontal side”) with a length equal to the run, a second side (“vertical side”) with a length equal to the rise, the horizontal angle being the angle between the first side and the hypotenuse and the vertical angle being the angle between the second side and the hypotenuse; cutting a pair of template triangles for each tread; securing a first of each pair of template triangles to an inside surface of a first stringer with the hypotenuse of each template triangle parallel to and even with an upper edge of the first stringer and in line with the hypotenuse of an adjacent template triangle; securing a second of each pair of template triangles to an inside surface of a second stringer with the hypotenuse of each template triangle parallel to and even with an upper edge of the second stringer and in line with the hypotenuse of an adjacent template triangle; cutting a top end of both stringers whereby a back edge of each stringer will be parallel to a perimeter joist to which the stair unit is attachable; cutting a bottom end of both stringers whereby a front edge of each stringer is be parallel to the back edge and a bottom edge of the bottom end is perpendicular to the front edge and substantially parallel to a lower landing surface; and securing a plurality of tread modules between the stringers, each tread module being in a one-to-one relationship with a corresponding pair of template triangles, a top surface of a tread plank of each tread module abutting a bottom edge of the horizontal side of the pair of template triangles, thereby forming the stair unit.