An adhesive-free, generally planar, tile of substantially rectangular cross-sectional shape, composed of substantially resilient, plastic material with respective top and bottom surfaces and a plurality of edge interlock top structures comprising:
- a multi-sided, central portion having integral, elongated first, second, third and fourth peripheral interlock element support edges extending therefrom, said support edges having a generally rectangular cross-sectional shape with top and bottom surfaces and a thickness less than that of said central portion, each of said support edges having respective inner and outer sides with the inner sides thereof integral with different respective sides of said central portion, first and second ones of said support edges intersecting at substantially right angles to form a first pair of said support edges and a first tile corner, third and fourth ones of said support edges intersecting at substantially right angles to form a second pair of said support edges and a second tile corner, the top surfaces of said first pair of said support edges extending substantially flush with the adjoining top surface of said central portion to complete the top surface of the tile and the bottom surfaces of said first edge pair joined to their respective first and second sides of said central portion between the top and bottom surfaces thereof, the top surfaces of said second pair of said support edges extending from and joined to their respective third and fourth sides of said central portion between the top and bottom central portion surfaces, and the bottom surfaces of said second edge pair extending substantially flush with the bottom surface of said central portion,
- a plurality of first sets of female interlock elements spaced-apart on each of said first and second pairs of said support edges, and a plurality of second sets of adjoining male and female disposed between spaced-apart from first sets of elements,
- said first and second sets of interlocks on said first pair of said support edges facing the plane of the top tile surface and said first and second interlocks on said second pair of said support edges facing the plane of the bottom tile surface, said male interlocks and their respective support edges facing their corresponding planes, and being spaced therefrom provide substantially flush top and bottom tile surfaces with contiguous tiles having substantially identical and inverted interlock elements, each of the male elements of said first interlock sets comprising a projection having a sidewall portion depending substantially perpendicularly from an underlying support edge,
- each of the male elements of said second interlock sets comprising a wall member depending substantially perpendicularly from an underlying support edge and having respective inner and outer laterally spaced sidewalls, said wall member extending transversely between said inner and outer edges of said support edge with the outer sidewall thereof spaced laterally therefrom a distance substantially equal to the width of said second element sidewalls, thereby forming contiguous channel sections as the female interlock elements of said second interlock pair,
- said inner sidewall of each of said second interlock set being sized and shaped substantially identically to that of an inverted one of said male interlock elements of said first set to form a plurality of cavitated female interlocks for said first set into which inverted, mating male elements of said first interlock set may be inverted, whereby said tile may be interlocked with contiguous tiles having a substantially identical pattern of interlocks thereon.