The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
Flashing details for cladding using profiled metals should:
- have two lines of defence at any point,
- not rely entirely on sealant,
- not unnecessarily bridge the cavity, and
- give water a means of escape when it does get in.
Details from WANZ, cladding suppliers, or bespoke solutions may be used. In the case of bespoke solutions, it is critical that the intersection of the different elements is considered holistically, particularly at the critical head/jamb flashing intersection. Changing one element of a proprietary solution may have unconsidered ramifications on the performance of other elements.