A tile support insert of the present invention is used with a conventional tile having an upper portion formed by a plurality of intersecting cross members, and a lower portion formed by a plurality of spaced support legs. The tile support insert has a core plate with a plurality of openings formed therein for receiving support legs of a conventional tile. The insert prevents the support legs from deforming when a heavy, localized load is placed on the tile. The tile support insert will typically extend upwardly a sufficient distance also to support the interconnecting cross members which form the upper surface of tile. When nested together, the tile and the tile support insert can form a generally contiguous tile which dramatically increases the load bearing capacity of the tile.