L.H. Boulton, Les Boulton & Associates Ltd. Auckland, New Zealand
Corrosion of building services is sometimes attributed to cost-cutting by the building owner, the constructor, or the building services designer. Lack of proper maintenance is another contributing factor to building corrosion problems. Inadequate weather tightness of the cladding on a building that results in the ingress of water into a building envelope can also contribute to corrosion of building assets. In recent years higher incidences of corrosion in building water piping systems have occurred. Water pipework corrosion experienced in institutional buildings can sometimes be attributed to lower water quality contained in the supply pipework. Lack of a proper water management protocol and incorrect water piping commissioning practices in new buildings have resulted in initiation of microbiological influenced corrosion (MIC) in water supply lines.
Another issue that needs to be addressed is the practice of building service engineers to specify dissimilar metal contacts in heating, ventilation and air conditioning systems (HVAC) water systems. The performance of some HVAC equipment can be compromised from new by the use of dissimilar metal contacts that increase the risk of galvanic corrosion in the plant. Many building owners are unaware that appropriate corrosion prevention measures, such as using more stainless steel, are more cost-effective than replacing building service equipment that has failed due to corrosion. Case studies are presented on corrosion of building assets including HVAC equipment, water piping and building claddings. An outline is given of good industry practices to avoid known types of corrosion encountered in building services.