Abstract: A stairway construction, specifically, an articulating self-supporting staircase. The staircase comprises a plurality of individual, interconnected elements, each element having a tread and a riser. A new wedge locking means to lock the interconnected elements firmly together is disclosed. This construction allows for a variety of widths, materials and layouts of the elements and is sufficiently strong to comply with building codes yet is light weight and easy to install in a variety of configurations. Modularity of assembly and ease of construction is achieved which provides an improvemenmt over the prior art.