A general contactor litigated against a number of his subcontractors when a fire sprinkler piping system in a new condominium building suffered numerous leaks in the CPVC distribution pipes. Exponent’s client, a well-established fire sprinkler system installer, indicated they had done nothing unusual. Exponent staff conducted days of meticulous on-site visual and microscopic examination of piping removed from the building. Failure patterns were characterized and identified as environmental stress cracking (ESC) caused by an external contaminant. The contaminant was compared to the contractor’s list of allowed construction materials and identified by FTIR as soldering flux used to install copper potable water lines. This implicated the plumbing contractor who had installed the copper system after the fire sprinkler installer had completed the installation of the CPVC sprinkler piping.
Exponent was subsequently able to demonstrate ESC failure in a CPVC pipe laboratory coupon exposed to the same soldering flux.