Winda Beacon · Library
Insulation keeps the heat in, and it can also hold water against the steel, out of sight under the cladding. Take a cut-away line apart in six steps: how water gets in, where it gathers, why it stays and how the damage is found.
Illustrative model, not to scale
Insulation keeps the heat in, and it can also hold water against the steel.
The cladding hides the steel. CUI is a form of external corrosion that cannot be seen from outside.