A compliant insert for flexibly supporting a synthetic floor tile above a ground surface that includes one or more elongate bodies, with each elongate body having a longitudinal axis oriented parallel to a top surface of the floor tile, a top face having an attachment interface for coupling to a tile support structure extending downward from an underside of the floor tile, and a bottom face of having at least one contact flat for contacting the ground surface and at least one upwardly-directed recess for allowing liquids to flow underneath the insert. Each of the elongate bodies also has a thickness and stiffness sufficient, in an unloaded state, to elevate the support structure a distance above the ground surface.