Galvanised Steel
Galvanised sheeting is a high quality hot dipped zinc coated steel with no additional finishes added. Now the base material for Polyester paint and PVC Plastisol coated roofing sheets, galvanised steel sheets have been used for over 100 years.
It is worth noting that galvanised steel will weather over time and become duller. Also galvanised steel can vary in finish and we highly recommend taking a coated sheet if colour is an issue.
As long as the material is fitted and treated properly then it can last a number of years, however the material is very susceptible to corrosion especially the steel underneath the zinc coating. We do not recommend using galvanised sheets within 3 miles of the coast as coastal environments can significantly decrease lifespan.
Galvanised steel sheets can sometimes be confused with stainless steel, however it is important to note these are different products.
Please be aware that galvanised sheets cannot be painted until they have weathered. This usually takes approx 6 months. If a more durable coloured finish is required please consider polyester painted or PVC plastisol sheets
Galvanised steel is not a colour and surface finish is not consistent. As the steel weathers you will see discolouration in areas. Over time the surface will become rougher as the material weathers. If you require a more consistent finish we would recommend using a coated steel finish such as polyester paint or PVC plastisol.
Care should also be taken when storing galvanised sheets. We recommend storing indoors at a consistent temperature to avoid water ingress and weathering whilst still stacked. Also degreasing the sheets is recommended to remove any excess rolling oil as this may cause reactions when the steel begins to weather.
Typical properties
| Property | Unit of measure | Value | Test standard |
|---|---|---|---|
| Standard zinc coating | (g/m2) | 275 (Z275) | |
| Minimum yield stress | (N/mm2) | 220 (S220GD) | EN 10147:2000 |
| Bending and profiling quality | DX51D | EN 10142:2000 | |
| Estimated time to first maintenance¹: Dry and unpolluted Suburban and rural Industrial and urban Coastal |
(years) (years) (years) (years) |
20-50 5-10 2-5 1-5 |
|
| Fire classification | A1 | BS EN 13501 |
Steel gauges
0.5mm (24swg)
0.5mm is a lightweight gauge ideal for use on walls and smaller domestic and agricultural roofs. With a typical weight of only 4.8kg/m². 0.5mm gauge steel cladding is especially useful when weight is a concern. Please be aware that if you are planning to use 0.5mm gauge sheets on your roof then you must support the sheets more often², typically every 0.6m (or 2ft).
0.7mm (22swg)
0.7mm steel cladding is the established standard for roofing applications with a typical weight of 6.8Kg/m². 0.7mm gauge can typically be supported² every 1m.
