the ribs 21 shown in fig2 as with previous embodiments the spaces between the ribs may be filled with a foam material alternatively some or all of the ribs may be excluded completely whilst still using the foam filler as in the configuration shown for a single arch in fig1 in use the structural member may be used with several similar members adjacent to it to form a floor or deck and so on they may also be configured with adjacent members perpendicular or at inclined angles to accommodate this connection portions 41 44 as shown in fig5 amp 6 may be included to facilitate connection to adjacent structural members or to inter connect members as described below fig7 shows an example of two of the members shown in fig5 connected together by connection members 71 the connection members have outstanding portions 74 which are shaped to engage the recess portions 41 provided on the structural member the two members to be connected are bonded together along their abutting surfaces 72 and to the connection members along interfaces 75 and 76 it is also envisaged that the connecting members will be connected to each other via a web portion not shown which rungs between the edges of the members 1 then in order to join.