Secondary Fasteners

Secondary fasteners are fixings that attach flashings to sheets and one another to transfer loads and provide lap sealing. Rivets and stitching screws are secondary fasteners used to fasten flashing laps. They are subject to shear loading due to expansion and differential movement.

Sealing washers are required on all secondary fasteners, except under rivets which should themselves be sealed or self-sealing.

Revision Category: 
2 - Editing and rearrangement
Revision Detail: 

Completely revised clause.

Draft Clause: