A concrete flooring system for outdoor urban contexts destined for community use, shared enjoyment and joie de vivre. The Exa project is based on the concept of “problems and opportunities” associated with the industry of surface coverings. Wherever a grout between one tile and another presents a “problem”, Exa creates an “opportunity” by transforming it into a sort of modular calligraphy, a neverending loop which links the textural pattern of the surface covering with its “grout”. The project is therefore subdivided into 3 hexagonal modules, each one of which may be further split into two or three parts or left intact. In this way, the modules enable highly customizable configurations, whilst creating a graphic design that is always original and “tailor-made”. In brief, the technical grout becomes an aesthetic element in its own right, thus enhancing the overall decorative effect.