Have you ever wondered about the cause of a ruptured pipe inside a structure in the dead of winter, and been puzzled because the pipe burst occurred in a heated area? It may seem counter-intuitive, but the cause may have been due to frozen piping.
Conventional wisdom is that pipes rupture from freeze damage when ice forms in the pipe, and since water expands during freezing (unlike most other liquids) by approximately 9%, the rupture occurs at the ice plug. However, that is not always the case.
For example, if a section of the water supply piping is not in the heated zone and is not sufficiently insulated, an ice plug may form in that section of piping. This may occur when the piping is in a garage or attic space. As the ice plug grows, the ice/water combination expands in volume. Since water is incompressible, the expansion will cause a dramatic increase in pressure in the piping. Tests have shown pressures in such situations can approach 2000 psi.
Most piping and fittings will not withstand such high pressures, and the result can be a rupture, which will occur at the weakest area of piping or fittings. That rupture may consequently occur far removed from the ice plug formation, even in heated areas of the structure. Therefore, freeze damage should not be ruled out for ruptured piping in a heated building without further investigation.
Roger Davis, a senior consulting engineer at The Warren Group, is a licensed professional engineer in South Carolina, North Carolina, Alabama, Georgia and Mississippi. He holds a Bachelor of Science in Mechanical Engineering and a Master of Business Administration from the University of South Carolina. He’s also achieved a Certificate in Crane Safety from the Georgia Institute of Technology, Distance Learning and Professional Education Center, Atlanta, Georgia. Roger is a certified fire and explosion investigator and certified vehicle fire investigator. He is experienced with municipal water, sanitary sewer, and storm water system design, construction, and operations. His expertise also includes property damage and personal injury investigations involving municipal utilities. He is an accomplished gas and diesel engine mechanic and has more than 30 years of experience with hydraulic plumbing and piping issues. Roger has investigated claims and injuries ranging from pressure piping system failures and material and personnel handling equipment to large engine failures and fires involving machinery, generators and vehicles.