Rondo conducted a 15-month investigation into imported steel wall and ceiling products. This involved six rounds of independent laboratory testing on steel products sourced from over five Australian suppliers importing from China.

Our investigation revealed several issues with these tested products, including non-compliance with Australian Standards and other requirements, poor quality, incorrect markings, and inadequate coating protection. These problems can compromise the safety, workmanship, and durability of buildings, especially in critical applications like ceilings and fire-rated walls.

Since steel systems are often concealed by plasterboard, it can be challenging to identify the specific steel products used. This report highlights the need to assess and verify the compliance, quality, and durability of steel components prior to construction.

Over the coming weeks we will be releasing findings from our investigation. These findings relate to the more than five suppliers that we investigated covering the following products: Steel Stud, Wall Track, Deflection Head Track, Furring Channel, Top Hat, and angles.

Our first findings release focuses on the steel product’s Base Metal Thickness (BMT) which refers to the thickness of the steel material before any coatings or treatments are applied. This measurement determines the strength, structural adequacy and suitability of the steel for specific applications.

Non-Compliance with to AS/NZS 4600 Light Gauge Steel Design Standard

To comply with AS/NZS 4600, designers of cold-formed steel structures must adhere to the specifications outlined in clause 1.5.1.5 ‘Acceptance of Steels’ of the AS/NZS 4600, which requires that the uncoated minimum steel thickness at any point in the cold-formed product, as delivered to the job site, be at least 95% of the thickness used in its design.

Our investigation revealed a concerning issue with some of the tested imported steel products that were marked as 0.50 BMT but the steel studs had actual measurements ranging between 0.46- 0.47 BMT and furring channels 0.45-0.46 BMT—meaning the BMT was 92-94% and 90-92% respectively of the specified thickness. Furthermore, some steel tracks marked 0.55 BMT showed test results of only 0.47-0.48 BMT, with only 85-87% of the specified BMT.

Consequently, these components would be non-compliant if designers use 0.50 BMT or 0.55 BMT to calculate the load capacities of wall or ceiling systems. This is particularly troubling when it comes to safety-critical fire-rated walls, external walls and ceiling systems.

Test results of some of the wall and ceiling components we tested:

Furthermore, a contractor received a Rondo Installation Guide from an importer’s reseller for installing some of the tested imported steel products. Rondo's technical literature is designed exclusively for use with Rondo products, as our engineers' calculations are based on detailed testing, tolerances, and performance specific to Rondo steel products, which significantly differ from those of the tested imported steel products. This situation highlights how using our technical data with non-Rondo products can lead to non-compliant design and installation outcomes as our wall heights and load tables have been developed using our specified BMT.

Base Metal Thickness Markings:

During our investigations, some of the imported steel products were marked as 0.50 BMT, yet our testing revealed that some stud and track components were instead 0.46-0.47 BMT and the furring channels were all 0.45-0.46 BMT.

Our investigation also found one importer’s product catalogue advertising steel stud as 0.50 BMT and track as 0.55 BMT, yet their own publicly available test data indicates the actual base metal thickness to be 0.468 BMT and 0.484 BMT, respectively. Customers might base their purchasing decisions on the advertised BMT figures, assuming they are getting stronger and more durable wall and ceiling components than they are.

Possible implications of reduced Base Metal Thickness (BMT):

Zinc coatings play a pivotal role in safeguarding the steel against corrosion, as they act as a sacrificial barrier to ensure a longer-lasting product. In some cases, importers may source steel from overseas with a thinner zinc coating as a way of reducing costs, which impacts the protection against corrosion and deterioration of the steel.

Failing to meet recommendations in AS/NZS 2785:2020 Suspended Ceiling Standards:

The Australian Standards for Suspended Ceilings AS2785:2020 recommend in clause F.4 that steel coating protection for all ceilings inside the building envelope that are more than 300m from breaking surf should be a minimum of Z180, and for ceilings outside the building envelope, a minimum steel coating of Z275 should be used in areas more than 1km from salt water.

Our testing program of various steel products from different importers showed a common trend where the Furring Channels were below the recommended zinc coatings outlined in AS2785:2020. Tested Furring Channels ranged between Z100-Z140. As the zinc coating sacrifices itself to protect the steel, these tested imported steel products have less protection to corrosion than Rondo steel furring channels which have a Z275 coating.

Low Zinc Coating impacting Corrosion Protection

The most common sign of steel deterioration is rust, and no one wants rust in their building. Deterioration depends on variables such as the environment and the product properties, which includes the steel’s zinc coating.

Characteristics of wall and ceiling steel components such as the thickness of zinc coating are not always detectable by sight.

Our investigation found the zinc coating mass of a variety of 0.5-0.55 BMT steel stud and track products tested, had a range between 99-122 g/m² of zinc coating applied (sum of both sides), compared to Rondo’s 275 g/m² for the same components. Additionally, in the components that Rondo tested, the heavy gauge deflection head tracks tested which are typically installed in external wall applications, only had a zinc coating of 171-179 g/m² applied compared to Rondo’s 275 g/m² for the same components.

Our investigation uncovered some communications on public platforms where local importers referred to their steel products as “equivalent” or the “same as” Rondo. This is despite differences in steel base metal thickness, zinc coating protection, shape, manufacturing tolerances, and the absence of Rondo's innovative features, such as hemmed edges on steel studs, as well structural ribbing and knurling for stiffening. These differences highlight that the imported products tested are therefore not equivalent and should not be used where Rondo has been specified.

The below guide provides essential insights for evaluating the compliance, quality, and durability of steel components. It outlines key questions and critical factors to consider, especially when comparing with Rondo products, to ensure your walls and ceilings are constructed with high-quality, compliant, and long-lasting steel materials.

• Base Metal Thickness with Comprehensive Test Data?
• Zinc coating steel protection for a long-lasting product?
• Evidence of testing in fire-rated and acoustic plasterboard systems?
• Tested for seismic performance compliance?
• Steel stud with hemmed edges for added strength?
• Structural ribbing on steel stud for added strength?
• Structural knurl on steel stud for stiffening of component?
• Compliance with AS/NZS 4600 using specified design thicknesses?
• Meets AS/NZS 2785:2020 Suspended Ceiling Standards?
• Recommended by Australian Plasterboard Manufacturers?

It is essential that steel products used in walls and ceilings with fire-rated requirements fully comply with the National Construction Code (NCC) Specification C2D9. This ensures that the materials meet the necessary safety standards for fire resistance and provide adequate protection in case of a fire. 

No Evidence of Fire Compliance Testing:

We were unable to find any evidence that the importers we investigated had conducted fire compliance testing with plasterboard in accordance with NCC Specification C2D9 for fire-rated walls or ceilings. In some cases, the imported steel products relied on comparisons to the yield strength and ultimate strength of Rondo steel to claim equivalency.

As detailed, there are numerous differences between Rondo and the imported steel products we tested, particularly in steel base metal thickness, which is critical for fire performance.

Non-compatibility with Knauf and CSR Fire-Rated Systems:

Knauf and CSR are leaders in the Australian plasterboard industry, as well as joint venture owners of Rondo. To ensure optimal performance in an integrated system with their plasterboard, Rondo collaborates with both companies in the research, testing and development of our products. This partnership aims to provide peace of mind and ensure optimal performance.

For fire compliance, Knauf and CSR used Rondo steel in their fire test reports. Our investigation into imported steel revealed some of the steel studs, tracks, and furring channels had differences in the base metal thickness compared to Rondo and the variations between the BMT of the same sized products, may indicate greater differences in their manufacturing tolerances. The variations revealed in the imported products we tested mean they are not equivalent to the Rondo steel used in Knauf and CSR fire-rated systems and are therefore non-compatible.

To ensure a compliant fire-rated system is being installed to prevent the possibility of reputational damage, harm and litigation, it is important to ensure Contractors are installing trusted brands with proven testing.

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