Corrosion protection for steelwork – New technical specification

Hot dip galvanization process

Standards New Zealand has published a new technical specification, SNZ TS 3404:2018 Durability requirements for steel structures and components. It covers the corrosion protection of structural steelwork exposed to New Zealand atmospheric and non-atmospheric environments.

Asset owners, designers (engineers and architects), contractors, specifiers of corrosion protection systems, and the surface coating industry can use this technical specification, which:

  • provides an advanced framework for specifying the durability requirements for steel structures and components in atmospheric and in non-atmospheric environments – this includes above ground and below ground
  • will enable durability requirements to be met without over-specification or under-specification of coating systems.

The technical specification:

  • updates the information contained in section 5 of NZS 3404.1:2009 Steel structures Standard – Materials, fabrication, and construction and is republished as a stand-alone technical specification
  • is a simplification of the design procedure for durability determination given in Heavy Engineering and Research Association Report R4-133:2011 New Zealand Steelwork Corrosion and Coatings Guide
  • is intended to be used to ensure that structural steelwork is sufficiently durable meet the requirements of the NZ Building Code Clause B2; the New Zealand Transport Agency (NZTA) Bridge manual, the NZTA Protective coatings for steel bridges; as well as remain compatible with NZS 3404:1997 Steel structures Standard
  • should be used together with AS/NZS 2312.1:2014 Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings – Part 1: Paint coatings and AS/NZS 2312.2:2014 Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings – Part 2: Hot dip galvanizing. As the fabrication and erection provisions of NZS 3404 are in the process of being superseded by AS/NZS 5131:2016 Structural steelwork – Fabrication and erection and AS/NZS 5100.6:2017 Bridge design – Part 6: Steel and composite construction, the technical specification is also written to be compatible with those documents.

Buy SNZ TS 3404:2018

Image by jimpg2_2015 CC BY-SA 2.0 (, via Wikimedia Commons

Published in engineering.