Abstract: An interconnection system incorporating a sliding locking member facilitating secured interengagement between a purlin and rafter. The sliding locking member is constructed for slip fit engagement within an extruded section of the purlin and for flanged interlocking with a rafter disposed orthogonally thereto. The purlin further includes an overhanging lip for engaging a web region or vent leg or vent wall of a gutter of the rafter and preventing lateral movement in a first direction. The sliding member prevents movement between the purlin and rafter in second and third orthogonal directions to thereby provide a triaxial securement system that is effected by a single sliding member that is easily moved or slid into position.