When sourcing used carports, the structural integrity is paramount. You must verify the material composition, prioritizing galvanized steel frames for rust resistance or high-grade aluminum for lightweight durability. Check the gauge thickness of the metal (typically 12-gauge or 14-gauge); a lower gauge indicates thicker, stronger steel. Additionally, inspect the roofing panels for signs of oxidation or structural fatigue, and ensure the truss system is intact to handle local snow and wind load requirements.