External corrosion of underslab, copper, hot water tubing has resulted in a great deal of construction defect litigation. In some cases, failures have been attributed to thermogalvanic corrosion between adjacent hot and cold copper tubing. This paper presents and discusses field and laboratory data gathered on thermogalvanic corrosion of underslab copper tubing. Field data include changes in pipe to soil potentials with increase in temperature, cathodic protection current requirement testing and the effectiveness of polyvinyl sleeving for corrosion control. Laboratory data on thermogalvanic corrosion cells in soil/water systems and 3% sodium chloride are also presented and discussed.
Keywords: Thermogalvanic, copper, hot water, underground, underslab, corrosion, soil