PPGI (Pre-Painted Galvanized Iron) is a pre-painted galvanized steel sheet, which is made of galvanized steel (substrate) coated with multi-layer organic coating (primer + topcoat), which is corrosion-resistant, weather-resistant, and decorative and a PPGI roof is a finished sheet made of PPGI coil or PPGI sheet that is molded to have a concave-convex shape on the surface. PPGI roofing sheet is a finished sheet with a concave or convex surface made of PPGI coil or PPGI sheet after molding.
PPGI roofing sheet combines the characteristics of steel sheet, zinc coating, paint coating and corrugated sheet to provide excellent mechanical, chemical and cost performance.
- Strong corrosion resistance: galvanized substrate + coating double protection, resistant to salt spray, acid rain.
- Light weight and high strength: light weight (5-12kg/㎡), high pressure-bearing capacity.
- Aesthetics and diversity: a variety of colors and surface textures (imitation wood grain, stone grain).
- Convenient installation: can be cut on site, short construction period.
- Low maintenance cost: no need for frequent repainting, long service life.
PPGI roofing sheet is widely used in different climatic environments in the fields of construction, industry, and agriculture.
Construction: industrial plants, warehouses, commercial building roofs, and walls.
Agriculture: greenhouses and farms.
Public facilities: airports, stadiums, and station canopies.
Home: garage, sun room roof.
Currently, Wanzhi Group sells the most popular types of PPGI roofing panels, such as PPGI corrugated panels, PPGI trapezoidal panels, and so on.
| Panel Type | Feature | Applicable Scenarios |
|---|---|---|
| Corrugated Panel | Strong wind resistance, fast drainage | Roofs in rainy areas |
| Trapezoidal Panel | High load carrying capacity, large span | Large-span factory buildings |
| Concealed fastening panel | No exposed screws, aesthetic | High-end commercial buildings |
| Locking Seam Panel | Watertight, suitable for low-slope roofs | Flat roofs or gently sloping roofs |
Wanzhi provides customized color service, you can choose the color according to the color card, or also make the color according to the sample.
Standard colors: Aquamarine, Brick Red, Ivory, Dark Gray, Grass Green.
Customized color: Support RAL color card or Pantone color number customization.
Color: Matte, High-gloss, Wrinkle
Pattern: Wood grain, imitation brick pattern, floral pattern, marble pattern, etc.
The coating of PPGI roofing determines the service life of the sheet; common coating materials are PE, SMP, PVDF, HDP, PVC, PU, etc., with corrosion resistance of 10-30 years.
Coating type Feature Lifespan (Outdoor)
PE (Polyester) Low cost, rich color, general weathering resistance, 10 years
PVDF (Fluorocarbon) UV and chemical resistance, high price, 15-20 years
HDP (Highly Weatherable Polyester) Between PE and PVDF, cost-effective for 15 years
Normal environment (urban, non-coastal): PE coating 5-8 years, PVDF coating 15-20 years.
Highly corrosive environments (coastal, industrial areas): 30%-50% shorter life span, need to choose zinc-aluminum-plated substrate (PPGL) + PVDF coating.
Substrate: Galvanized ≥ Z120 (120g/m² on both sides) or Aluminized Zinc Plated AZ150.
Coating: PVDF film thickness ≥ 20μm (front side), PE ≥ 15μm.
Certifications: Conforms to ASTM A755, GB/T 12754, or EN 10169 standards.
Wanzhi Group’s factory is located in Boxing County, Binzhou City, Shandong Province, China, our company Shandong Wanzhi Steel has passed ISO9001, ISO14001, and other certificates, supports SGS, BV, and other factory inspections. (If you are looking for roofing sheet suppliers, you can check the qualifications, certificates, production capacity, services, and other aspects, multiple suppliers comparison, and choose the most suitable roofing sheet suppliers. )
Qualification: ISO 9001 quality management system certification, environmental protection certification.
Production capacity: manufacturers with monthly production capacity of ≥5000 tons are more reliable.
Service: Provide samples, customization, technical support and after-sales warranty (at least 10 years).
The price of PPGI Roofing sheet is 600-900USD per ton, the price per sheet is 1-10USD, the price is ultimately determined by the substrate, coating, surface treatment, quantity and other factors.
Normal PE coating: low (Z80 substrate).
PVDF coating: medium (Z120 substrate).
Aluminum zinc plated substrate (PPGL): High (AZ150+PVDF).
Substrate treatment: galvanized steel sheet is cleaned, degreased and passivated.
Coating: Roller coating primer → baking → top coating → second baking.
Forming: Processed into wave sheet, trapezoidal sheet, etc. by pressing machine.
Industrial buildings: factories, warehouses, logistics centers.
Commercial buildings: supermarkets, showrooms, stadiums.
Agricultural buildings: greenhouses, livestock sheds.
Public facilities: stations, airports, schools.
Feasible: However, thin sheets (≤0.5mm) and ductile substrates (e.g. DX54D) are required.
Limitations: Bending radius needs to be ≥15 times the sheet thickness to avoid cracking of the coating.
Color coated roof panels can be used in coastal areas, but coastal and high-temperature/high-humidity environments require substrates and functional coatings that are more resistant to corrosion.
Substrate: Aluminized zinc (PPGL AZ150).
Coating: PVDF, film thickness ≥ 25μm.
Cut-out treatment: coated with zinc epoxy primer.
Similarly, the use of PPGI as a roofing material in industrial/salt spray areas requires a high performance paint coating to enhance corrosion and chemical resistance.
Applicable: Choose high plating (Z180+) + PVDF coating for resistance to acids, alkalis and chemical gases.
PPGI steel is popular for wall panels, wall decoration, curtain walls, and other materials.
Concealed fasteners or faux wood grain panels are widely used on building facades for both functionality and aesthetics.
Fixing method: self-tapping screws (with EPDM adhesive pads) or hidden fastening.
Lap requirements:
Horizontal lap ≥200mm (when slope <10°).
Sealant is required for longitudinal lap.
- Feasible: However, thin sheets (≤0.5mm) and ductile substrates (e.g. DX54D) are required.
- Limitations: Bending radius needs to be ≥15 times the sheet thickness to avoid cracking of the coating.
Color coated roof panels can be used in coastal areas, but coastal and high temperature/high humidity environments require substrates and functional coatings that are more resistant to corrosion.
- Substrate: Aluminized zinc (PPGL AZ150).
- Coating: PVDF, film thickness ≥ 25μm.
- Cut-out treatment: coated with zinc epoxy primer.
Similarly, the use of PPGI as a roofing material in industrial/salt spray areas requires a high performance paint coating to enhance corrosion and chemical resistance.
Applicable: Choose high plating (Z180+) + PVDF coating for resistance to acids, alkalis and chemical gases.
PPGI steel is popular for wall panel, wall decoration, curtain wall and other materials.
Concealed fasteners or faux wood grain panels are widely used on building facades for both functionality and aesthetics.
Fixing method: self-tapping screws (with EPDM adhesive pads) or hidden fastening.
Lap requirements:
- Horizontal lap ≥200mm (when slope <10°).
- Sealant is required for longitudinal laps.
PPGI has good corrosion resistance and durability, and does not require special maintenance during application. If you want to extend the service life of PPGI roofing sheet, you can carry out simple cleaning regularly.
Routine Maintenance: Clean the surface 1-2 times a year and check the condition of the screws and coating.
No special maintenance is required: unless the coating is broken or the cut-outs are rusted.
Standard configuration (PVDF+Z120 substrate):
General area: 15-20 years.
Coastal/industrial area: 10-15 years.
Yes . After cleaning the surface, spray fluorocarbon or polyurethane paint of the same color.
PPGI Roof coatings can peel and rust for various reasons, most commonly due to poor manufacturing processes and installation practices.
Causes:
- Installation scratches or cuts are not treated.
- Long-term UV aging + acid rain.
- Insufficient galvanization of the base material (e.g., Z80 for coastal areas).
Solution: Apply special metallic paint and repair the galvanization.
Detect the cause of the leakage first, and then repair it.
Checkpoints:
- Whether the lap length is up to standard.
- Whether the screws are loose or the rubber gasket is deteriorated.
- Whether the board is deformed (needs to be replaced).
- Repair: Use waterproof glue (such as silicone glue) to fill the gap.
- White rust: wipe with 5% acetic acid solution → rinse with water → topcoat with zinc-based paint.
- Discoloration: Spray the same color top coat after cleaning (slight discoloration will not affect the performance).
- Tools: Soft bristle brush/sponge + Neutral detergent (pH 6-8).
- Contraindications: Steel wool, strong acid/alkali detergents are prohibited.
PPGI steel is one of the most cost-effective roofing materials. For short-term projects where you want to save more money, you can choose sprayed and economical coatings as an alternative.
- Alternatives:
Ordinary galvanized sheet + on-site coating: 30% lower cost, but only 3-5 years of life. - PPGI-PE coating: 30%-40% less expensive than PVDF.
| Comparison | PPGI (galvanized) | PPGL (galvalume) |
|---|---|---|
| Corrosion resistance | Suitable for a general environment | Salt spray resistance 2-6 times higher, suitable for coastal/industrial |
| Cost | lower | 20%-30% higher |
| High temperature performance | Temperature resistance ≤120°C | Temperature resistance ≤150°C (Aluminum component antioxidant) |
| Recommended scenarios | Inland cities, non-corrosive industrial areas | Coastal, chemical plants, high-temperature workshops |