A modular sub-flooring system for supporting an overlayment above a ground surface includes a plurality of sub-floor tiles situated about a ground surface, with each sub-floor tile having a substantially-flat top surface that is adapted to receive and support an overlayment, and a connection interface with opposing engagement surfaces. The sub-flooring system also includes a plurality of removable bridge connectors, with each of the bridge connectors having a plurality of tile interfaces, and with each tile interface having complimentary engagement surfaces configured to engage with the opposing engagement surfaces of the connection interfaces. The tile interfaces of the bridge connectors couple to the respective connection interfaces of any adjacent sub-floor tiles to restrain the relative vertical movement between the adjacent sub-floor tiles while facilitating controlled relative lateral movement between the sub-floor tiles.