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XXXXXXXXXX ca-pub-XXXXXXXXXXAluminium vs GI Sheet Comparison Calculator
Compare weight, cost, lifespan, and corrosion risk for your specific location — side by side.
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XXXXXXXXXX ca-pub-XXXXXXXXXXHow to Use This Calculator
- Enter roof area — measure the actual roof surface (slope area), not the floor plan below it.
- Select sheet thickness — the same gauge is applied to both GI and aluminium for a fair comparison.
- Choose your location type — coastal and industrial environments accelerate corrosion on GI sheets significantly.
- Click Compare Materials — side-by-side results show weight, cost range, expected lifespan, and a location-based recommendation.
GI vs Aluminium — Quick Reference
| Property | GI Sheet | Aluminium Sheet |
|---|---|---|
| Density | 7,850 kg/m³ | 2,700 kg/m³ |
| IS Standard | IS 277 | IS 737 |
| Typical lifespan — Normal area | 15–20 years | 30–40 years |
| Typical lifespan — Coastal area | 8–12 years | 25–35 years |
| Typical lifespan — Industrial area | 10–15 years | 20–30 years |
| Approximate cost (per kg) | ₹75–95 | ₹220–280 |
| Maintenance | Repainting every 5–7 yrs (coastal/industrial) | Virtually maintenance-free |
| Weight at 0.47mm, 100 m² | ≈ 369 kg | ≈ 127 kg |
When to Choose GI Sheet
- Budget is the primary constraint and location is inland or rural
- Short-term structure (temporary sheds, 10–15 year horizon)
- Standard corrugated profiles are needed — GI has far more profile options
- Local fabricators are more familiar with GI cutting and fixing
When to Choose Aluminium Sheet
- Location is coastal (within 50km of sea) or in a heavy industrial area
- Long service life required — 25–40 years with no repainting
- Structural load matters — aluminium is approximately 65% lighter than GI
- Total cost of ownership (materials + maintenance over lifespan) is the metric
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XXXXXXXXXX ca-pub-XXXXXXXXXXFrequently Asked Questions
Is aluminium roofing sheet better than GI?
It depends on location and budget. Aluminium is better for coastal and industrial areas because it resists corrosion without repainting, lasts 25–40 years, and is much lighter. GI is the better choice for inland rural or semi-urban projects where the lower upfront cost matters and corrosion risk is low. Neither is universally better — location is the deciding factor.
What is the price difference between aluminium and GI sheets?
Aluminium costs approximately ₹220–280 per kg, while GI costs ₹75–95 per kg — roughly 3× higher per kg. However, aluminium is about 65% lighter than GI at the same thickness, so the actual cost difference per square metre is closer to 1.5–2×. For a 100 m² roof at 0.47mm, expect aluminium to cost around ₹28,000–35,000 vs ₹28,000–35,000 for GI. Use this calculator to get figures for your specific area.
Which sheet is better for coastal areas?
Aluminium is strongly recommended for coastal locations (within 50km of sea). Salt-laden air causes GI sheets to rust within 8–12 years even with paint protection, requiring repeated repainting and eventual replacement. Aluminium forms a natural oxide layer that stops corrosion without any coating, lasting 25–35 years in coastal environments with no maintenance costs.
How much lighter is aluminium compared to GI sheet?
Aluminium (density 2,700 kg/m³) is approximately 65.6% lighter than GI (density 7,850 kg/m³) at the same thickness. For a 100 m² roof at 0.47mm: GI weighs about 369 kg while aluminium weighs about 127 kg — a saving of 242 kg. This lighter load reduces stress on purlins, trusses, and columns, which can lower the structural steel cost on large sheds.
What is the IS standard for aluminium roofing sheets?
Aluminium sheets for roofing in India conform to IS 737, which covers wrought aluminium and aluminium alloy sheet, strip, and foil for general engineering purposes. GI (galvanised iron) roofing sheets conform to IS 277. When purchasing, always ask the supplier for a test certificate confirming IS compliance and the coating weight (for GI) or alloy grade (for aluminium).