Corrosion Resistant PPGI PPGL Steel Coils with White Colour and 30-275g/m² Zinc Layer
When selecting coated steel for roofing, construction, or manufacturing, many buyers face the same question: PPGI or PPGL – which is better?
Although both are prepainted steel products, their base materials and performance differ significantly. This guide provides a clear comparison to help you choose the right material based on your project requirements.
PPGI (Prepainted Galvanized Steel) is produced by coating paint layers on galvanized steel (zinc-coated substrate). It offers a good balance between cost, corrosion resistance, and aesthetic appearance.
Widely used in:
- Residential roofing
- Wall panels
- Home appliances
PPGL (Prepainted Galvalume Steel) is made by applying coatings on galvalume steel (55% aluminum + zinc alloy). It provides superior corrosion resistance and longer service life.
Widely used in:
- Industrial buildings
- Coastal projects
- High-end roofing systems
| Product name | Colour Coated Steel Coil |
| Base material | GI /GL coils |
| Thickness | 0.12 – 1.50 mm |
| Width | 600 – 1250 mm |
| Zinc coating | Z30 – Z275 g/m² |
| Paint type | PE / SMP / PVDF |
| Top Coating Thickness | 10 – 25 μm |
| Back Coating Thickness | 5 – 10 μm |
| Colour | RAL Color / Custom |
| Surface finish | Glossy / Matte / Textured |
| Standard | ASTM A653 / EN 10346 / JIS G3312 |
| Property | PPGL | PPGI | GI |
| Corrosion Resistance | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐ |
| Durability | 20~25years | 10~15years | 5~10years |
| Aesthetic Appearance | Excellent | Good | Basic |
| Cost | High | Medium | Low |
| Application Level | High-end projects | Standard projects | Basic structures |
- High durability & large projects → PPGL
- Balanced performance → PPGI
- Cost-sensitive structures → GI
- PE: Cost-effective, general purpose
- SMP: Improved UV resistance
- HDP: High durability for outdoor use
- PVDF: Maximum weather resistance (recommended for coastal projects)
- For roofing, SMP or PVDF is highly recommended
PPGL performs significantly better due to aluminum content, which provides barrier protection and slows corrosion.
PPGL lasts 3–6 times longer than GI-based materials
PPGL reflects more solar heat, helping reduce building temperature.
Ideal for roofing in hot climates
PPGI has a lower initial cost, making it suitable for budget projects.
PPGL, while more expensive, reduces long-term maintenance and replacement costs.
Both materials offer similar paint finishes and color options, suitable for architectural design.
The main difference is the base coating: PPGI uses zinc, while PPGL uses aluminum-zinc alloy, offering better corrosion resistance.
PPGL is better for long-term and harsh environments, while PPGI is suitable for general roofing.
Yes, but it provides a longer lifespan and lower maintenance cost, making it more cost-effective in the long run.
Yes in mild environments, but not recommended for coastal or industrial areas.
PPGL typically lasts 20–25 years, while PPGI lasts around 10–15 years.
Yes, both PPGI and PPGL can be customized with RAL colors and special finishes.
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