Forensic Engineering Research and Testing of Building Copper Tube Water Piping System Freeze Failures

Abstract

Forensic engineers investigating water loss incidents, caused by water leaking from damaged copper tube piping systems inside buildings, are tasked with determining if that damage is from the piping being exposed to subfreezing temperatures or some other cause. This paper provides guidance for such investigations and factual basis for such opinions, including presenting the results of experimental testing of water-filled copper tube piping systems exposed to subfreezing conditions. It also discusses piping standards and building codes. When ice forms a solid plug inside a pipe, the portion of the piping downstream of that plug becomes isolated. As the ice plug grows, the pressure in the isolated portion of the piping system increases dramatically from hydraulic pressure until the strength of the “weak link” is exceeded, which causes a rupture that relieves the pressure. Oftentimes, no significant water flows through the rupture at that time because the ice plug prevents water flow through the pipe. However, significant water flow occurs once the plug melts. This paper demonstrates why it is critically important for forensic engineers to understand this sequence of events.