Designers and tradespeople should have an understanding of the mechanism of the corrosion process to comply with the requirements of this section of the Code of Practice. See Corrosion (NZBC: B2 – Durability)

Corrosion is defined as the reaction of a material with its environment, resulting in measurable alteration which may impair the performance of a component or an entire system. Corrosion can result from direct contact with another metal or substance, or as the result of run-off, fall-out, poor design or installation that would allow ponding. In some cases, metal can corrode when it is either exposed to or denied contact with oxygen.

All fittings, such as fans, fitted above a penetration flashing, must be made from compatible materials and there must be no runoff onto penetration flashings from incompatible materials.
Condensate from air conditioning units must not be discharged onto metal roof cladding, but must be separately drained to an inert gutter or downpipe.

Where the roofing contract does not include the over-flashing or installation of the cowlings for a penetration, the designer and the installer assumes responsibility to comply with this COP, as the roofing contractor is not responsible for the work of others.


Revision Category: 
0 - Clause Removed
Revision Detail: 

Incorporated into "Durability".

Draft Clause: