Three=dimensional lattice work structure covering - has vertical bars between raised panel portions and nodal points

摘要

The covering is for a three-dimensional lattice-work structure of struts joined at nodal points, and comprises plastic panels each with a raised central portion. There is a vertical tension or thrust bar (7) running between the central portion of the panel (3) and a nodal point. The panels can each be distorted in two opposite directions and can be profiled along their edges so that the surfaces of enclosing joint strips are flush with theirs, typically with flanges extending downwards. The design subjects the panels mainly to tension loads rather than bending loads, so that the amount of material used can be reduced.