Material Thickness

Material thickness has a great bearing on load capacity and buckling resistance. For residential buildings, 0.40 mm thickness material is most commonly used for corrugated and trapezoidal profiles, and this will normally be sufficient to withstand the statutory wind loads at typical spans and fastener spacings in up to High Wind Zones. In higher wind speeds, it is often more effective to use 0.55 mm material, rather than reducing purlin and fastener spacings.

Material with a 0.40 mm thickness is very vulnerable to foot traffic damage in most profile configurations and requires careful and accurate foot placement to avoid buckling. In residential buildings with high foot traffic expectancy or highly visible roofs, eg, multi-level mono-pitch roofs, roofs with UV collectors, flues, aircon devices, chimneys that need servicing, or prestige housing 0.55 mm material should be selected.

For commercial and industrial applications, 0.55 mm is almost universally used on the roof, and 0.40 mm is most common on walls.

In addition to 0.40 mm and 0.55 mm, 0.48 mm G550 steel is often used for high tensile trough sections, which will often compare in strength to similar profiles manufactured from 0.55 mm G300 material. Most roofing profiles can also be manufactured from 0.75 mm G550 material where greater robustness and resistance to foot traffic are desired.

Material is available with other thicknesses; for example, 0.63 mm material is often manufactured for the Pacific islands, and 0.35 mm is sometimes used to manufacture specialist wall cladding.