In Southeast Asia, especially in Singapore—a global hub for marine engineering and petrochemicals—steel grating is widely used across various applications. From the petrochemical complexes on Jurong Island to the drainage systems at Marina Bay, and the drilling platforms in the South China Sea, metal grating is virtually everywhere.
However, the requirements for bar grating differ significantly between offshore platforms and onshore industrial facilities. Overlooking these differences can lead to catastrophic corrosion failure or prohibitively high maintenance costs.
This article provides a detailed comparison from three perspectives: corrosion level, material selection, and maintenance cost, drawing on authoritative data from China and Singapore to help industry professionals make optimal decisions.
1. Corrosion Level: The Gap Between C5 and CX
The environmental corrosion level is the primary consideration for material selection. According to ISO 9223/ISO 12944, atmospheric corrosivity is categorized into six levels, from C1 to CX.
Environmental Comparison List
| Dimension | Offshore Platform | Onshore Industrial Facility |
|---|---|---|
| Typical Environment | High salt spray, high humidity, splash zone, even immersion zone | Acid mist from chemical plants, urban drainage, general industrial plants |
| ISO Level | C5-M (Marine/High Salt) or CX (Extreme) | C3 (Medium) to C5-I (Industrial/High) |
| Corrosion Rate | Carbon steel corrosion rate > 1500 g/m²·year (CX level) | Carbon steel corrosion rate 200 – 1000 g/m²·year |
| Key Indicators | Chloride deposition > 150 mg/m²·day; must pass ASTM B117 salt spray test >1500 hours | SO₂ concentration, pH level, mechanical wear |
Authoritative Interpretation:
Singapore has a tropical maritime climate. For offshore platforms, the CX (Extreme) level is mandatory. According to GB/T 32119-2023 “Corrosion Control of Marine Steel Structures by Composite Petrolatum Coating,” the corrosion rate in the splash zone is several to dozens of times higher than in the atmospheric zone, necessitating cladding or heavy-duty anti-corrosion systems.
For onshore facilities, such as chemical plants on mainland Singapore, the corrosion requirements are less stringent. According to PSB certification standards, passing a 500-hour neutral salt spray test is typically sufficient. This data gap directly influences the selection of steel grating.
2. Material Selection: Hot-Dip Galvanized vs. Stainless Steel vs. Composite Coating
Based on the corrosion levels mentioned above, the selection logic for metal bar grating differs fundamentally.
2.1 Offshore Platforms: Preference for 316L Stainless Steel or Heavy-Duty Coating
In offshore environments, even carbon steel bar grating with hot-dip galvanizing struggles to withstand long-term chloride ion erosion.
Standard Requirements: The Chinese marine standard CB/T 608-1998 and international marine engineering practices require a zinc coating weight of ≥ 600g/m² (approx. 85μm). In CX environments, a zinc coating thickness of no less than 100μm is recommended, or 316L stainless steel should be used.
Trend: In recent years, for deep-sea oil and gas projects around Singapore, structural grating is increasingly using 316L stainless steel or a composite coating system combining “epoxy + thermal spray zinc” to ensure a service life of over 20 years with minimal maintenance.
2.2 Onshore Industrial Facilities: Cost-Effective Q235 with Hot-Dip Galvanizing
In onshore environments such as power plants, warehouses, or HDB (Housing & Development Board) drainage covers, industrial grating primarily withstands mechanical wear and moderate oxidative corrosion.
Mainstream Solution: Q235 material hot-dip galvanized steel grating.
Size Selection: Bar grating sizes typically range from 25×3 to 50×5 mm, with cross bar spacing of 50mm or 100mm.
Local Applications: For many garden terraces and drainage projects in Singapore, to meet aesthetic and safety requirements, dense welded steel grating (where the bearing bar spacing is less than 25mm) is used as grating panel to prevent high heels from getting caught or small objects from falling through.
3. Maintenance Cost: Life-Cycle Economic Analysis
Maintenance cost is the key differentiator between offshore and onshore requirements. On land, maintenance may mean “touching up paint”; offshore, it means “production stoppage” and extremely high labor costs for offshore operations.
Q&A: Why Must Offshore Platforms Abandon Carbon Steel?
Q1: If an offshore platform uses carbon steel hot-dip galvanized grating, the initial procurement cost could be 30% lower. Is it worth it?
A: No, it is not worth it.
According to a 2025 survey by the China Steel Construction Society, in high-corrosion environments similar to offshore platforms, ordinary galvanized steel grating can reach 60% rust rate within 2 years. The replacement cost is 2.8 times the original procurement cost.
Considering Singapore’s labor costs and offshore downtime losses, while the upfront investment in stainless steel grating is 15-30% higher, the total lifecycle cost (over 15 years) is 40-60% lower. For offshore platforms, the long-term value of custom grating far outweighs the short-term price difference.
Q2: How should maintenance plans be established for onshore industrial plants?
A: Onshore maintenance should focus on “graded prevention.”
A tiered maintenance system is recommended: For C4/C5 environments (such as the core chemical zone on Jurong Island), weekly inspections are required; for C3 environments (general warehouses), monthly inspections are sufficient. The annual cost of preventive maintenance is approximately SGD 15-20/m², whereas the cost of post-incident repair is as high as SGD 80-120/m².
4. Singapore Market Compliance Requirements
To use or sell steel grating in Singapore, local stringent standards must be met.
PSB Certification and SAFETY Mark:
PSB certification, managed by Enterprise Singapore, is critical for building material approval. Street grating used for drainage or critical access must pass rigorous testing. Data indicates that in 2023, about 38% of failed certifications were due to non-compliant anti-corrosion additive ratios.BCA Green Mark:
The Building and Construction Authority (BCA) enforces the Green Mark standard, which restricts heavy metal content (lead ≤1000ppm, cadmium ≤100ppm) in the surface treatment of grating systems. Steel grating suppliers must provide Material Safety Data Sheets (MSDS) and Life Cycle Assessment (LCA) reports with their products.Slip Resistance Safety:
According to the Ministry of Manpower (MOM) workplace safety requirements, safety grating used for pedestrian walkways must have high slip resistance. Serrated bearing bars or metal grating sheets with anti-slip raised surfaces are standard, and the coefficient of friction must meet SS standards.
5. Conclusion: How to Make the Right Choice?
| Application Scenario | Recommended Material | Surface Treatment | Reference Standard |
|---|---|---|---|
| Offshore Drilling Platform | 316L Stainless Steel or S235JR High-Strength Steel | Heavy-Duty Coating / Hot-Dip Galvanized (>100μm) | ISO 12944 CX, NORSOK M-501 |
| Jurong Island Chemical Plant | Q235B or 304 Stainless Steel | Hot-Dip Galvanized (>85μm) | PSB Certification, ISO 12944 C5 |
| Commercial Complex / HDB | Q235B Mild Steel | Hot-Dip Galvanized | SS Standards, ASTM A123 |
| Subway / Airport | Aluminum or Stainless Steel | Natural or Anodized | BCA Green Mark |
Conclusion:
The core difference in requirements for steel grating between offshore platforms and onshore industrial facilities is this: offshore platforms prioritize “corrosion-resistant service life” as the primary factor, preferring stainless steel or ultra-heavy galvanized structural grating; while onshore industrial facilities, while meeting the necessary anti-corrosion level, focus more on “load-bearing capacity and installation convenience.”
Whether choosing metal bar grating or rebar grating, it is recommended that owners and contractors base their decisions strictly on environmental corrosion data and calculate the full lifecycle cost, rather than focusing solely on the initial procurement price.
Bangtu – Your Premier Steel Grating Solution Partner
At Bangtu, we understand the demanding requirements from offshore to onshore applications in Singapore and Southeast Asia. As a professional grating manufacturer, we offer a comprehensive range of products, from carbon steel bar grating to high-quality stainless steel grating.
Whether you need PSB-certified custom grating or heavy-duty grating systems for CX-class offshore platforms, Bangtu provides precise grating bar selection advice and full lifecycle cost analysis. Choose Bangtu for safety and durability.
Tel/Whatsapp: +8613363180165
Email: james@bangtuwiremesh.com
Website: www.bangtusteelgrating.com | www.chinawiremesh.ru
Appendix: Referenced Standards and Literature
DB42/T1970-2023 “Technical Specification for Permeable Pavement in Sponge Cities”, Hubei Provincial Department of Housing and Urban-Rural Development, Issued 6 March 2023, Implemented 6 July 2023.
[Link: http://ebook.chinabuilding.com.cn/zbooklib/book/detail/show?SiteID=1&bookID=155403]Eighth Zijin Award Architecture and Environment Design Competition Award-winning Work “Reshaped by Water”, Work No. B121-000673, Nanjing Chimu Landscape Engineering Co., Ltd.
[Link: https://www.iarchis.cn/index.php?m=event&a=workdetail&id=9372]DB61/T1364-2020 “Design Specification for Permeable Pavement in Sponge Cities”, Shaanxi Provincial Department of Housing and Urban-Rural Development, Issued 15 September 2020, Implemented 15 October 2020.
[Link: http://ebook.chinabuilding.com.cn/zbooklib/book/detail/show?SiteID=1&bookID=155466]T/CCIAT 0014-2019 “Standard for Construction and Quality Acceptance of Sponge City Infrastructure”, China Construction Industry Association, Issued 1 December 2019, Implemented 1 February 2020.
[Link: https://www.gongbiaoku.com/book/58t19639i34]T/CASMES 264-2023 “Technical Specification for Permeable Pavement in Sponge Cities”, China Association of Small and Medium Enterprises, Issued 29 December 2023, Implemented 31 December 2023.
[Link: https://www.bzchaxun.com/view/8137074046000000.html]15J012-1 “Environmental Landscape – Detailed Construction of Outdoor Engineering”, China Institute of Building Standard Design & Research, Implemented 1 January 2016.
[Link: https://ebook.chinabuilding.com.cn/zbooklib/book/detail/show?bookID=60825&SiteID=1]BCA Green Mark Scheme (Version 8.0) “Green Mark for Non-Residential Buildings”, Building and Construction Authority of Singapore, Issued 1 November 2024.
[Link: https://www.sgbc.sg/bca-sgbc-green-mark-interiors/]SS EN 10025-2:2019 “Hot rolled products of structural steels — Part 2: Technical delivery conditions for non-alloy structural steels”, Singapore Standards Council, Issued 1 September 2019.
[Link: https://www.singaporestandardseshop.sg/Product/ProductDetail?ID=SS%20EN%2010025-2%3A2019]PSB Certification Scheme for Building Materials
[Link: https://www.enterprisesg.gov.sg/]- China Steel Construction Society, “2025 Annual Survey Report on Steel Structure Industry Corrosion Data”, China Steel Construction Society, Issued August 2025.
[Link: http://www.cncscs.org.cn]
