Step Apron

A step apron or waterfall flashing must be used where the length of roof cladding is more than can be transported, or exceeds the recommended length for expansion as shown in Roof Cladding Expansion Provisions.

The designer should allow a minimum 20 mm step in the purlin height to accommodate a step apron, giving a total change of height equal to 20 mm plus the profile height. The purlin height can be adjusted at the purlin cleat or by using a different size purlin. 



Clause Number:
Revision Category: 
2 - Editing and rearrangement
Revision Detail: 

Removed reference to "Fortress Fasteners" in drawing A:  Step Apron Details.

Draft Clause: