1. Types of Metals Commonly Used in Construction

Carbon Steel is Iron alloyed with carbon in varying percentage and other metals in small quantities such as nickel or tungsten to suit the strength and behaviour characteristics required.

Stainless Steel is Iron alloyed with a min of 12% chromium (Cr) providing a full depth of protection (isolation) against corrosion. It does this in fact by forming a thin surface layer of chromium oxide which prevents further damage.

Aluminium as a material is largely resistant to damage caused by corrosion though it does corrode. But in doing so this thin layer of ‘aluminium oxide’ creates a protective layer to the elements thus halting further degradation of the base metal. This can be an issue where it is subject to other materials and contaminants.

Copper largely used in pipework but also as a roofing material. The corrosion process of copper is often desired due to its aesthetics. Even though this may be used for aesthetics, the causation of the aesthetic appearance / architectural effect of the works as a result can be classed defective under the BCA and the QBSA Act 1991. Make sure the owner is aware of the consequences of this and ensure that the effect and non-compliance is documented and accepted in writing by the designer and owner prior to commencement.

Zinc used extensively as a sacrificial metal applied to Iron and Steel in the form of paint or galvanising and in its own right in a lesser extent as a cladding material.