Material, Thickness, & Lifespan Comparison: 840 vs. 900 Color-Coated Steel Roofing Tiles
A comprehensive engineering guide for structural selection, comparing 840, 900, 820, and 760 Klip-Lok profile systems for industrial and commercial projects.
High-Performance Metal Roofing Profiles
Roof corrugated sheets are ribbed, profiled roofing materials crafted from galvanized steel, color-coated steel, or aluminum alloy. Core engineering grades include SGCC galvanized steel, DX51D+Z, and 304 stainless steel. Their signature wavy profile boosts structural rigidity, while advanced surface treatments like hot-dip galvanizing, PVDF coating, or anodizing enhance weather resistance. With thicknesses ranging from 0.3mm to 1.2mm, standard widths from 900mm to 1200mm, and customizable lengths, they satisfy tailored roofing requirements globally.
Their core advantages are well-suited for industrial roofing needs: the corrugated design delivers exceptional load-bearing capacity to withstand heavy snow and wind loads. Coated surfaces provide strong waterproofing and corrosion resistance for long-term outdoor use. They are lightweight yet robust, simplifying transportation and installation while offering outstanding cost-effectiveness compared to traditional tile roofing, balancing performance and budget for diverse building types.
Dimensional & Material Specification Matrix
A detailed comparative breakdown of 840 Model, 900 Model, 820 Model, and 760 Model roofing tiles across mechanical, chemical, and commercial parameters.
| Parameters | 840 Profiled Tile | 900 Profiled Tile | 820 Klip-Lok (角驰) | 760 Standing Seam (角驰) |
|---|---|---|---|---|
| Effective Width | 840 mm | 900 mm | 820 mm | 760 mm |
| Wave Height & Pitch | Height: 25mm | Pitch: 210mm | Height: 15mm | Pitch: 125mm | Height: 50mm | Pitch: 410mm | Height: 76mm | Pitch: 380mm |
| Unfolded Width | 1000 mm | 1000 mm | 1000 mm | 1000 mm |
| Substrate Grade | SGCC / DX51D+Z / Aluzinc | SGCC / DX51D+Z / Aluzinc | DX51D+AZ / G550 Aluzinc | G550 Aluzinc / 304 Stainless Steel |
| Coating Types | PE / SMP / HDP | PE / SMP | HDP / PVDF Fluorocarbon | PVDF / Premium HDP Coating |
| Zinc/Aluzinc Mass | 40 - 120 g/m² | 40 - 80 g/m² | 80 - 180 g/m² | 120 - 275 g/m² |
| Common Thicknesses | 0.30 - 0.60 mm | 0.30 - 0.50 mm | 0.45 - 0.60 mm | 0.50 - 0.80 mm |
| Theoretical Weight (0.5mm) | Approx. 4.25 kg/m | Approx. 4.25 kg/m | Approx. 4.35 kg/m | Approx. 4.45 kg/m |
| Market Price Index | Baseline (100%) | 95% - 98% of Baseline | 115% - 125% of Baseline | 130% - 150% of Baseline |
| Service Lifespan | 10 - 20 Years | 8 - 15 Years | 15 - 25 Years | 20 - 35+ Years |
| Wind & Snow Resistance | Medium-High | Medium | High (Clip Lock) | Extreme (Standing Seam) |
| Primary Application | Industrial roofs & walls | Residential & light wall cladding | Large-span commercial roofs | Heavy industrial & coastal roofs |
Substrate Grades & Anti-Corrosion Coatings
The durability of prepainted steel roofing tiles depends directly on the core substrate and the chemical formulation of the exterior protective coating layers.
Core Substrate Materials
The base metal provides structural strength and primary corrosion defenses:
- SGCC / DX51D+Z: Hot-dip galvanized steel with robust zinc coatings for baseline structural and general outdoor projects.
- Galvalume (Aluzinc): 55% Al-Zn alloy coating that delivers up to 3-6 times the corrosion resistance of standard galvanizing.
- 304 Stainless Steel: The ultimate choice for chemical processing facilities and highly corrosive coastal environments.
Coating Formulations
Exterior paint layers shield the steel core from UV rays, humidity, and acid rain:
- PE (Polyester): Standard option, offering 7-12 years of color stability. Ideal for mild climates.
- SMP / HDP: Silicon Modified Polyester and High Durability Polyester. Excellent UV defense with 15-20 years of fade resistance.
- PVDF (Fluorocarbon): Top-tier fluorocarbon coating. Resists chemical attack, chalking, and UV fading for over 25-30 years.
Zinc Coating Weights
The thickness of the zinc layer determines the sacrificial protection rate:
- Z60 - Z80: Optimized for temporary buildings, interior panels, and dry regions.
- Z120 - Z180: Recommended standard for medium-duty industrial roofs and warehouses.
- Z275 (275g/m²): Heavy galvanizing for extreme outdoor moisture, high humidity, and marine environments.
Typical Project Selection Scenarios
How to choose the correct model, material, and coating thickness based on building functions and structural loads.
Industrial & Commercial Project Configurations
Different structures demand specific structural profiles and coating formulations to balance cost, performance, and long-term durability. Below are five typical selection configurations deployed globally:
Note: For chemical plants or coastal projects within 5km of the sea, we strongly recommend choosing 760 Standing Seam with PVDF coating or 304 Stainless Steel base sheets to prevent rapid edge rust.
Export Standard Packaging & Quality Certification
To ensure that the profiled color-coated steel sheets reach international job sites in pristine condition, Shandong Bamaoxing Steel Co., Ltd. enforces strict seaworthy export packing protocols. Each bundle is wrapped in waterproof paper, protected by a plastic film barrier and heavy-duty steel corner guards, securely strapped with high-tensile steel bands, and mounted on solid wooden or steel pallets designed for containerized ocean freight.
Frequently Asked Questions
Expert technical answers regarding tolerances, installation, structural requirements, and ordering logistics.
Q1: What is the standard thickness tolerance for your color-coated roofing sheets?
According to international standards (ASTM A653 / EN 10143), our standard thickness tolerance is within ±0.02mm. For premium projects, we can supply high-precision sheets with a tolerance of ±0.01mm. We guarantee that the delivered thickness matches the ordered specification without intentional thinning.
Q2: How do you test and verify the zinc coating weight?
We verify the zinc/aluzinc coating mass through third-party magnetic testing instruments and chemical strip-and-weigh methods. Customers receive Mill Test Certificates (MTC) with each shipment. We also support on-site testing by third-party inspection firms such as SGS or BV before loading.
Q3: What rust prevention measures are taken for the cut edges of the tiles?
The zinc or aluzinc layer provides sacrificial protection to the cut edges. However, for highly corrosive environments, we recommend applying edge-sealing anti-rust paint or using protective film during profiling to prevent mechanical scratches that could compromise the zinc layer.
Q4: What is the recommended overlapping and waterproof design for 840 vs. 900 models?
The 840 model requires a minimum lap of one wave crest for roofs with a slope greater than 10%, and two wave crests for slopes below 10%. The 900 model, having a lower wave height (15mm), is best suited for wall panels or steep roofs, requiring a full crest lap plus waterproof sealant beads at the overlap joint.
Q5: What are the recommended purlin spacings for different thicknesses?
For 0.4mm thick sheets, the recommended purlin spacing is 800mm to 1000mm. For 0.5mm sheets, spacing can be increased to 1000mm to 1200mm. For 0.6mm sheets, a spacing of up to 1500mm is permissible under standard wind and snow load conditions. Heavy snow load regions require closer spacing.
Q6: What is the Minimum Order Quantity (MOQ) and delivery lead time?
Our standard MOQ is 1 ton for standard profiles and RAL colors in stock. For custom colors or special substrates, the MOQ is 5 to 10 tons. Standard orders are manufactured and dispatched within 10 to 20 days after receiving the deposit or Letter of Credit (L/C).
Get a Custom Profile Selection & Quotation
As a leading brand, Shandong Bamaoxing Steel Co., Ltd. is a premier manufacturer of prepainted, galvanized, and galvalume steel sheets. We offer custom roll forming, protective film application, bending, and shearing services. Submit your roof dimensions and environmental conditions below to receive an optimized engineering quote.