PEX, or cross-linked polyethylene, is one of the most widely used materials in modern residential and commercial water supply systems. Valued for its flexibility, corrosion resistance, and lower cost compared to copper, it has largely replaced traditional piping materials in new construction. When a PEX failure leads to a water-loss claim, both the material and the installation warrant investigation, as both are equally responsible for failures observed in the field.
In this episode of Evidence to Answers, forensic engineer Mark covers the three main PEX connection systems: copper crimp, stainless clamp, and expansion poly rings. He explains the critical installation details that affect joint integrity, and well as the most common failure modes, including freeze-related fitting failures, oxidative attack in hot-water systems, improperly seated joints, degraded acetal fittings, and damage from rodents or heat. He also walks through what experts look for at a joint that is separated, including evidence of insertion, cracking, degradation, and pull-out indicators.
This video is for those involved in losses where PEX piping is a factor. Capturing the full manufacturer pin printing on the pipe, which includes the manufacturer, date codes, and pipe specifications, along with in-place documentation before removal, is essential to a complete evaluation.