8 39 9 39 10 39 and 12 39 as will be best observed from fig2 4 the longitudinal mesh wires 23 and 24 will traverse each pair of angularly related sides 16 and 17 of the trusses in spaced relation to their connected apex 18 and in accordance wtih the present invention the longitudinal mesh members 23 and 24 are bonded as by spot welding to sides 16 and 17 to provide a rigid two point triangular support for the outwardly projecting apexes 18 also as will be observed the joinder of transverse wires 25 and 28 to longitudinal wires 26 and 27 are at positions spaced from the joinders of the truss members to the longitudinal wires thereby spacing apexes 18 from any of the transversely extending wires 25 and 28 moreover the several truss members are positioned so that the apexes 18 of transversely adjacent truss members are offset longitudinally from each other with the apexes defining a diamond shaped pattern as seen in the front view fig1 in accordance with the present invention one or more partitions 26 and 27 are carried by truss members 13 between sections 11 and 12 and as a feature of the present invention these partitions may comprise a simple sheet pierced by apexes 18 and mounted interiorly of the adjacent mesh section and supported on.