and 1b respectively the tread cap apparatus 100 comprises a stair tread 102 a nosing 104 a riser cap 110 a cove moulding 112 and a shoe moulding 114 in fig1 a the nosing 104 is connects to an edge portion of the stair tread 102 and is placed adjacent to a top portion of the riser cap 110 the cove moulding 112 connects to a bottom portion of the nosing 104 finally the shoe moulding 114 is placed near a bottom portion of the riser cap 110 to apply the tread cap apparatus 100 an existing nosing of the existing stair step is removed along with any cove and shoe mouldings that may exist removal of the existing cove and shoe mouldings provide for the riser cap 106 to be flush against an existing step riser of the stair step when applied the tread cap apparatus 100 is then fitted onto the existing stair step with the stair tread 102 covering an existing step tread the riser cap 110 covering the existing step riser and the nosing 104 the cove moulding 112 and the shoe moulding 114 then being placed accordingly an aspect of this embodiment includes a first substrate layer 106 to provide additional strength and stress absorption to the tread cap apparatus 100 the first substrate layer 106 further can be used to reduce any stress to the nosing 104 and prevent the nosing.