Structural Zone is a mixture of 40-60 mm clean stones and ScapeSpec Tree Pit media (TP120) which meets engineering requirements for a load-bearing paving base, while allowing tree pits to be extended beneath hard surfacing.An organic hydrogel prevents the soil and stone from separating during the mixing and installation process. The compacted stone and soil mix has 20-30% void space for the storage and dispersal of airand water.
