Galvanized iron (GI) sheets are a cornerstone of construction in the Philippines, valued for their durability, affordability, and versatility. Whether for roofing, fencing, or industrial applications, these sheets provide essential protection against the country’s tropical climate. However, choosing the right thickness is critical to ensuring both durability and cost-effectiveness. This guide explores the importance of the thickness of GI sheets in the Philippines, its impact on local industries, and practical advice for selecting the best option for your needs.
Introduction to Galvanized Iron Sheets
Galvanized iron sheets are zinc-coated steel sheets to guard against corrosion. The zinc coating serves as a shield that does not allow moisture and oxygen to pass through and reach the steel core, thus providing rust and weather resistance. In the Philippines, these sheets are extensively utilized since they can endure heavy rains, powerful winds, and periodic typhoons.
These sheets are most commonly used for roofing due to their lightweight yet strong nature. They are also applied for fencing, partitions, and industrial purposes like machinery components and storage containers. Thickness is the most important factor that determines how efficiently these materials work in different situations.
Why Thickness Matters
The thickness of these sheets directly affects their strength, durability, and ability to withstand external forces. Regulatory bodies in the Philippines have established minimum standards to ensure safety and quality across applications.
Understanding Thickness Requirements
Thicker sheets are more appropriate for regions that experience harsh weather conditions. For example, roofing materials should have a minimum Total Coated Thickness (TCT) of 0.4 mm as required by the Department of Trade and Industry (DTI) to ensure they can support heavy rain and strong winds. Thinner sheets can be used for less stressful applications such as fencing or as a decorative item but are not appropriate for structural purposes.
Besides, thickness determines longevity. Thicker sheets are more resistant to corrosion and longer lasting than thinner sheets. For application in the industries where materials experience mechanical stress or undergo rigorous environments, thicker sheets are a requirement.
Impact on Local Industries
The regulation of GI sheet imports by the DTI is intended to safeguard local producers from being priced out by lower-cost but inferior foreign products. Local producers tend to make GI sheets that meet Philippine National Standards (PNS), which detail requirements like zinc coating thickness and material strength. Maintaining these producers sustains employment and economic growth while providing stable product quality.
Choosing the Right Thickness for Your Needs
Selecting the appropriate thickness depends on your specific application, budget, and environmental factors. GI sheets come in a range of thicknesses, typically measured in millimeters or gauges (with lower gauge numbers indicating thicker sheets).
Applications and Thickness Options
Roofing
Roofing requires durable materials capable of withstanding high wind speeds and heavy rain. A recommended thickness of 0.4 mm or thicker is advised, as thicker sheets provide better structural integrity and longer lifespans.
Fencing
Fencing does not face as much stress as roofing materials, making thinner sheets more suitable. A recommended thickness of 0.12 mm to 0.25 mm is often used, as it is more cost-effective while still providing adequate protection.
Industrial Use
For machinery parts or storage containers exposed to mechanical stress or corrosive environments, thicker sheets are ideal. The recommended thickness varies based on the specific application, but sheets as thick as 0.7 mm are often used to ensure durability and resistance.
Compliance with National Standards
The Philippine National Standards (PNS) define certain thickness and zinc coating requirements for GI sheets. The minimum recommended zinc coating for maximum corrosion protection is 20 µm per side, which is 275 g/m². Calipers can be used to check sheet thickness, and coating gauges can measure consistency of zinc layers. By doing so, you prevent yourself from using low-quality materials that are likely to fail prematurely due to extreme conditions.
Practical Tips for Purchasing GI Sheets
When buying GI sheets in the Philippines, keep these tips in mind:
Measure in Millimeters
Thickness is best measured in millimeters rather than gauge numbers to avoid confusion.
Check Certifications
Ensure the product complies with DTI regulations and carries a Philippine Standard (PS) mark.
Inspect Zinc Coating
Verify that the zinc coating meets the recommended thickness for corrosion resistance.
Match Thickness to Application
Choose a thickness suitable for your intended use—thicker for roofing or industrial applications, thinner for fencing or decorative purposes.
Consider Local Suppliers
Purchasing from local manufacturers supports the economy and ensures compliance with Philippine standards.
Benefits of Choosing the Right Thickness
Selecting the correct GI sheet thickness offers several advantages:
Durability
Thicker sheets last longer by resisting corrosion and physical damage.
Safety
Meeting regulatory standards ensures structures can withstand extreme weather conditions.
Cost-Efficiency
While thicker sheets may cost more upfront, they reduce long-term maintenance expenses.
Support for Local Industries
Buying compliant products from domestic manufacturers strengthens the economy while ensuring quality.
Key Takeaway
Choosing the right thickness for GI sheets in the Philippines is essential for ensuring durability, safety, and cost-effectiveness in construction projects across the country. Whether you need roofing materials capable of withstanding typhoons or lightweight fencing solutions, selecting an appropriate thickness ensures your investment will stand the test of time. Supporting local manufacturers further guarantees compliance with regional requirements while contributing to economic growth.