An overview – Industrial coating to AS/NZS 5131

When it comes to protecting structural steel from the harshest environments, the right industrial coating can mean the difference between long-lasting performance and costly failure. Understanding AS/NZS 5131 compliance can ensure your projects stand the test of time. 

Industrial coatings play a vital role in protecting materials from corrosion across diverse environments, while also offering additional benefits such as aesthetics, passive fire protection, abrasion resistance, luminescence, and marine fouling prevention.  Compliance with standards like AS/NZS 5131, which governs the fabrication and erection of structural steel, is crucial to ensuring the durability and performance of coatings for structural steelwork. 

Sections 9 (Surface Treatment and Corrosion Protection) and Section 13 (Inspection, Testing, and Correction) of AS/NZS 5131 emphasise that protective coatings for structural steel should meet defined performance standards. These coatings are typically applied to safeguard steel structures from environmental conditions, including exposure to moisture, salts, chemicals, and pollutants. Coating systems are selected based on the steel’s exposure classification, as outlined in AS/NZS 2312, to ensure appropriate durability. Standards for cleaning, surface preparation, coating application, and inspection—as well as galvanizing requirements—are also referenced within AS/NZS 5131. 

Critical steps – surface preparation and application

For coatings to maintain their protective qualities over time, comprehensive surface preparation—such as cleaning and abrasive blasting to achieve the defined surface profile—is essential. Improper preparation accounts for nearly 70% of premature coating failures. Surface-tolerant paint systems can be an option when ideal surface preparation is not feasible, though stakeholders should carefully weigh the cost-benefit ratio in these cases. 

Industrial coatings can be applied through various methods, including spraying, brushing, or rolling, each offering specific advantages depending on the project. High-performance coatings—used in applications such as bridges, industrial plants, and offshore structures—are often applied using plural component pumps. For rapid-curing products with a short pot life, precise application techniques are critical to achieving consistent results.  

Inspection and innovation in coating technology

Like the welding process, coating inspection is also critical in ensuring that the coating process adheres to specifications, as improper application or curing can lead to premature failure. Coating inspections typically follow a multi-stage approach: pre-application checks, ongoing monitoring during application, and post-application assessments and further tests, and are necessary to ensure long-term durability is achieved.  

Innovations in this area can be followed through the Association for Materials Protection and Performance (AMPP), which was formed in 2021 from the merger of NACE and SSPC. As the largest global community for corrosion and coatings expertise, AMPP provides valuable resources for staying current with technological advancements in the evolving industrial coatings landscape. 

Strengthening inhouse expertise to support heavy engineering

Achieving long-lasting protection for structural steel requires more than just applying coatings; it demands a deep understanding of standards like AS/NZS 5131, thorough surface preparation, and precise application. Combining these with careful inspection ensures that coatings perform as intended and prevent costly premature failures. 

By working with experts who understand the delicate balance between selecting the right coating system and maintaining rigorous application processes, you can be confident that your projects meet standards, but also benefit from the latest advancements in coatings technology. This in turn enhances the durability and performance of your steel structures—ultimately saving time, resources, and future maintenance costs. 

That’s why I’m excited to share, that I recently earned my AMPP Certified Coating Inspector qualification, adding to my qualifications in welding and non-destructive testing. Now, with over 20 years of hands-on experience in coating inspection, I’m able to better anticipate potential issues and ensure compliance with standards like AS/NZS 5131. Moving forward, this capability means I will be able to offer deeper insights into coating systems, inspections, and standards compliance to better support our members and their projects, and I’m looking forward to leveraging these skills to deliver results for those I work with.