Blisters on insulated metal panels are typically more of a cosmetic concern than a structural one. Technically, a panel with blisters can perform comparably to one without, with minimal impact on the overall thermal efficiency of the building. More significant thermal losses generally occur through doorways and other intentional openings in a building rather than through blistered panels. However, blistering can worsen over time due to temperature changes. If a blister enlarges to cover more than 30% of a panel's surface area, FALK recommends addressing the issue. Such extensive blistering would be eligible for warrantable repair, replacement, or other corrective actions, provided that improper installation or site-specific factors did not cause the problem.