BlueScope Steel conducted the most rigorous testing program in COLORBOND steel's history to verify new enhancements in paint colour durability compared with the previous-generation product, and to support the introduction of six new colours into the range.

BlueScope product development portfolio leader Detlev Mueller explained the newly launched COLORBOND steel product was tested in several outdoor locations across the country for a minimum period of four years to ensure it would perform extremely well in challenging Australian conditions. 

According to Mr Mueller, they employed a unique testing program for COLORBOND steel wherein the test procedures replicated building applications in actual Australian conditions across multiple exposure sites ranging from moderate environments to very severe. 

BlueScope's testing procedure includes modified tests in which samples of COLORBOND steel are subjected to greater exposure than standard outdoor tests by being placed on what are dubbed 'hot racks'. These black, insulated boxes face north at 45 degrees to enable close simulation of the 'skin temperatures' of real insulated roofs.

When replicating actual building applications, the assessment structures featured different roof pitches, profiles and product types and also included unwashed areas.

Mr Mueller comments BlueScope's rigorous outdoor testing is an important distinction between COLORBOND steel and imported alternatives because COLORBOND steel has been designed and tested in Australia to perform well in local conditions. 

The six new colours – Basalt, Wallaby, Gully, Cove, Mangrove and Terrain – were narrowed down from 20 options under consideration, after engagement with specialist colour consultants and industry parties including architects, roll-formers, developers and builders.

Before finalising the final six new colours, many hundreds of panels were scrutinised over the four-year testing period. Testing of the new colours began in 2008 and involved all the 20 different candidate colours with up to 10 variants of each colour tested using different paint technologies and similarly included in the outdoor testing program.

The outdoor samples were examined by BlueScope's Weathering Laboratory, where accelerated testing using cyclic salt fog and ultra-violet light Q Panel machines were also used for complementary analysis. 

The outdoor exposure samples of the new COLORBOND steel were then analysed for degradation using a meter to measure gloss retention by looking at the scattering of reflected light. A colorimeter was used to see the change in colour caused by degradation of paint resin and pigments. The surface breakdown was also examined by removing material from the surface and measuring it.

BlueScope used the performance data to select the final six new colours. Mr Mueller said that all 22 COLORBOND steel colours have demonstrably better gloss retention compared with previous-generation COLORBOND steel sample panels based on testing from the same exposure sites.