Each tread and the top landing of a stairway, where risers are used, should have a nose which extends 1/2 inch to one inch beyond the face of the lower riser. Noses should have an even leading edge. You must ensure that all treads are reasonably slip-resistant and the nosings are of nonslip finish. Welded bar grating treads without nosings are acceptable providing the leading edge can be readily identified by personnel descending the stairway and provided the tread is serrated or is of definite nonslip design. You must ensure that rise height and tread width are uniform throughout any flight of stairs including any foundation structure used as one or more treads of the stairs.