BU627 The impact of geothermal environments on metals and wood (2018)

BRANZ conducted field trials in Rotorua to examine how metals degrade in geothermal environments. Different metals showed very different responses. The scope of NZS 3604:2011 Timber-framed buildings requires a 50 m separation from geothermal hot spots. This will not always reduce corrosion rates to a safe range.

Wood discolouration is likely to be the result of copper sulphide forming on/in wood treated with copper-based preservatives.

This bulletin covers:

• corrosion of mild steel, zinc and copper
• corrosion of aluminium and stainless steel
• the performance of aluminium-zinc alloy-coated steel
• distance effects of corrosion in geothermal environments
• discolouration of wood.