Primary Fasteners

Primary fasteners are fixings that attach flashings to the structural building frame and which should withstand all the loads applied to the cladding, including expansion provisions. Primary fasteners are relied on for structural performance. Flashings should be fastened at a point within 25 mm from the exposed edges of the flashing, and the primary fastener spacing should be to each structural member it crosses.

Flashings should be fixed on both edges.

Putting bonded or embossed washers under all primary fasteners through the horizontal upper surface of flashings improves weathertightness.