The difference in one paragraph
ZINCALUME® steel is an aluminium, zinc and magnesium alloy-coated steel with a bright metallic silver finish. COLORBOND® steel is that same base, with a baked-on paint system applied over it in a range of colours. COLORBOND® Ultra takes the same paint system and puts it over a heavier metallic alloy coating, giving it the highest corrosion resistance in the BlueScope range - the product BlueScope specify for sites close to breaking surf.
So the three products are not different steels. They are the same BlueScope base, built up in layers - ZINCALUME® with the alloy coating alone, COLORBOND® with an added paint system, and COLORBOND® Ultra with a heavier alloy coating plus the paint system. Which one suits your shed depends on how close you are to the coast and what you want the building to look like.
| ZINCALUME® | COLORBOND® | COLORBOND® Ultra | |
|---|---|---|---|
| Finish | Bright metallic silver | Baked-on paint in a full colour range | Baked-on paint in a full colour range over a heavier metallic coating |
| Colour choice | One — unpainted metallic | Wide range of 22 standard colours and 6 matt colours. | Same wide range of 22 standard colours and 6 matt colours. |
| Cost | Lowest | Higher | Highest - premium coastal grade |
| Corrosion resistance | Alloy coating only | Alloy coating plus a paint system over it | Thicker metallic alloy coating plus paint system - BlueScope's highest-durability coated steel |
| Best suited for | Rural sheds, farm buildings, industrial | Homes, garages, carports, patios - anything visible from the street | Sites close to breaking surf and severe marine environments |
| Heat and glare | Reflective but bright in full sun | Lighter colours reflect more heat; dark colours absorb more | Same thermal behaviour as standard COLORBOND® |
| Matching a house | Difficult | Straightforward - match roof, gutter and trim | Straightforward - same colour range as standard COLORBOND® |
| Common use | Rural sheds, farm buildings, industrial | Homes, garages, carports, patios, anything visible from the street | Beachside homes, coastal garages, carports and sheds within breaking-surf distance |





