What is blistering in the context of building panels?

Blistering refers to the formation of raised areas on the surface of building panels, such as exterior walls, façades, or less commonly, roofs. This often happens on parts of a structure that receive the most sunlight, particularly with darker exterior coatings that absorb more heat. Excessive heat can cause the steel in the panels to expand and potentially delaminate from the insulating foam core due to increased tension. Blisters may also form because of poor adhesive properties or incorrect installation procedures. High temperatures can exacerbate the issue by causing off-gassing, which contributes to blistering.