A modular access flooring system (100) comprising a plurality of reversible floor panels (103), each panel having a first and second surface suitable for orientation in an uppermost facing direction to provide the floor surface of the modular system. A plurality of support pillars (101) provide elevated support of the floor panels via respective pillar heads (102). Correct alignment of the floor panels is achieved via a spacer projection (106) extending upwardly from each pillar head and about which the floor panels may be arranged to form a tessellated modular flooring system.