galvanised steel
Galvanised steel is regular steel that has been coated with zinc to improve its resistance to corrosion. This protective zinc layer shields the underlying steel from rust caused by moisture, humid environments, or high humidity levels. The galvanisation process creates a sacrificial barrier between the zinc coating and the steel, ensuring optimal protection against rust promoting factors. Galvanised steel is a durable and reliable material that has been used for roofing and cladding products for over a century. It is made of high quality hot dipped zinc coated steel, with no additional coatings added. Galvanised steel now serves as the base material for coatings such as Polyester paint, PVDF paint and PVC Plastisol. When installed and maintained correctly, galvanised cladding and flashings can last for a number of years. However, it's important to note that the material is highly vulnerable to corrosion, particularly the steel beneath the zinc coating. For this reason, we advise against using galvanised sheets within three miles of the coast as coastal environments can significantly reduce their lifespan. It is important to keep in mind that galvanised steel will naturally weather and dull down over time. Additionally, the finish of galvanised steel can vary, so if color consistency is a concern, we strongly advise opting for a coated finish such as PCV Plastisol. Notes: It's not uncommon for galvanised steel sheets to be mistaken stainless steel, but it's important understand that these are two distinct finishes. Please note that galvanised sheets cannot be painted until they have weathered, which typically takes around six months. If you require a durable colored finish, we suggest considering polyester painted or PVC plastisol sheets. It's important to keep in mind that galvanised steel is not a colour and its surface finish is not uniform. As the steel weathers, you may notice discoloration in certain areas, and the surface will become rougher over time. For a more consistent finish, we recommend using a coated steel finish such as polyester paint or PVC plastisol. It's important to take proper care when storing galvanised sheets and flashings. We advise that they are stored indoors at a consistent temperature if possible. This is to prevent water ingress and minimise weathering while still stacked. Additionally, we recommend degreasing the sheets to remove any excess rolling oil, as this may cause reactions when the steel begins to weather. to discuss galvanised steel finishes in more detail please contact us.
finish properties
finish property | unit of measure | value | test standard |
---|---|---|---|
bending and profile quality | DX51D | EN 10142:2000 | |
minimum yield stress | N/mm2 | 220 (S220GD) | EN 10147:2000 |
zinc coating standard | g/m2 | 275 (Z275) | |
estimated time to first maintenance* | |||
dry and unpolluted | years | 20-50 | |
suburban and rural | years | 5-10 | |
industrial and urban | years | 2-5 | |
coastal | years | 1-5 | |
fire classification | A1 | BS EN 13501 |
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