The aluminum in the coating forms a highly effective barrier that resists oxidation, while the zinc offers sacrificial edge protection. The paint layer (polyester, SMP, or PVDF) adds UV resistance, color retention, and an attractive finish. As a result, PPGL roofing sheets have a significantly longer service life than PPGI sheets of equivalent coating weight.

Key properties:

● Excellent corrosion resistance, even in salt-laden or acidic atmospheres.

● High heat reflectivity, helping reduce building cooling costs.

● Good formability – can be roll-formed into various profiles without cracking.

● Wide range of colors and gloss levels.

● Lightweight (4–8 kg/m² depending on thickness) and easy to install.

● Fire resistance (steel core is non-combustible).

Typical standards: EN 10169 (European), ASTM A755 (American), JIS G3312 (Japanese), and AS/NZS 2728 (Australian/New Zealand). Common base steel grades: DX51D, DX52D, or structural grades like S250GD, S350GD. Aluminum-zinc coating weight is expressed as AZ (e.g., AZ100, AZ150, AZ200). For roofing, AZ150 (150 g/m² total) is typical. Paint systems: polyester (PE) for general use, silicon modified polyester (SMP) for better durability, and PVDF for premium UV and chemical resistance (25+ years).

Applications: residential and industrial roofing, agricultural buildings (sheds, barns, poultry houses), warehouses, carports, and coastal structures.

Main advantage over PPGI roofing sheet: PPGL offers much better corrosion resistance, especially at cut edges and in high-humidity environments. However, PPGL is slightly more expensive than PPGI. For most outdoor roofing applications, especially near the sea or in polluted areas, PPGL is the preferred choice. For inland, dry climates, PPGI may be sufficient and more economical.

Selection guidance: For coastal or industrial zones, choose PPGL with AZ150 or higher and a PVDF topcoat. For standard inland use, AZ100–AZ150 with a polyester topcoat is adequate. Always ensure the profile matches local installation requirements.