HERA R4-133: Setting a New Standard for Steel Durability in Aotearoa

Steel is central to New Zealand’s construction sector — powering everything from high-rise buildings and bridges to transport and energy infrastructure. But ensuring its long-term performance requires more than strength of design. Corrosion protection, durability planning, and fire performance are critical to keeping structures safe, resilient, and cost-effective over time.

That’s where HERA R4-133: New Zealand Steelwork Corrosion and Protection Guide comes in. Recently released in its fourth revision, the updated guide offers the industry a modern, expert-led resource designed to raise the bar on best practice for steel durability and protection.

Expert-led, industry-shaped

The guide — developed by Raed El-Sarraf (Structural Integrity Consultants), Willie Mandeno, and Hanieh Ghominejad (WSP) with Kaveh Andisheh (HERA) — has been refined through a nationwide consultation process. Feedback from corrosion experts, engineers, fabricators, and construction professionals was incorporated into the final version, ensuring it reflects both the latest research and the realities of the job site.

What’s new in the 4th revision?

Key enhancements include:

• Alignment with current standards — providing clear interpretation of SNZ TS 3404 to give designers confidence and consistency.
• Modernised protective coating systems — updated recommendations for coating selection, application, and maintenance, with stronger guidance on life-cycle planning.
• Integration of fire performance — new insights into how galvanised structural systems behave in fire, bridging the link between durability and fire safety.

Why it matters

The revised R4-133 is more than a technical reference. It’s a strategic resource that helps:

• Support resilient infrastructure in coastal and geothermal zones
• Enable life-cycle thinking to reduce maintenance costs
• Extend service life and reduce embodied carbon through reuse and durability

Looking ahead

HERA’s 4th revision of R4-133 represents a collective achievement. By blending technical expertise with industry-wide feedback, it sets a new benchmark for protecting steel in Aotearoa.

As Kaveh Andisheh, General Manager of Structural Systems at HERA, explains:

“This guide is a reflection of the sector’s shared ambition – to deliver steel structures that are durable, resilient, and sustainable for generations to come.”