Cut Edge Corrosion
What is cut-edge corrosion?
Cut edge corrosion is a common issue that often begins as edge peel at the cut edges of metal sheets. This typically happens when sheets are sheared to length, leaving the base metal unprotected. Interestingly, older generations of plastisol coatings used to fail across the entire roof. However, with the development of more durable coatings that have extended life expectancies (initially 25 years and now 40 years), cut edge corrosion has emerged as a distinct problem.
In recent years, various commissioned reports have drawn attention to the escalating levels of environmental pollution. Consequently, contaminated rainwater tends to accumulate in the exposed overlap joint due to capillary action and surface tension. This trapped rainwater eventually seeps into the coating, whether it's PVC, Plastisol, or Polyester, and leeches into the protective zinc oxide layer, thus exposing the bare metal. As more zinc becomes exposed higher up on the substrate, the factory-applied coating loses adhesion to the steel, resulting in lifting and curling. Ultimately, once both the top and reverse sides of the metal are exposed, corrosion takes place.
Cut Edge Corrosion Solutions: Cut edge corrosion occurs when the protective coating on metal roof sheets deteriorates over time, leaving the exposed edges vulnerable to rust and corrosion. At Cure Roofing, we offer a range of effective solutions to address this issue: