Galvalume Sheet: Types, Sizes, Roofing Applications & Suppliers
Industrial buildings18 Aug 2026
Table of contents
Introduction
What are Galvalume sheets?
Types of Galvalume sheets
Galvalume sheet sizes and specifications
Galvalume roofing applications
How to choose a Galvalume sheet supplier
Conclusion
FAQs
Introduction
Galvalume sheets are aluminium-zinc alloy-coated steel sheets used for roofing, cladding, and structural panels across construction and manufacturing in India. This guide covers the types available, standard sizes and coating specifications, where Galvalume performs best, and what to verify before choosing a supplier.
Specifications are referenced against IS 15961:2012; buyers should confirm current requirements against the latest edition, IS 15961:2025, available from the Bureau of Indian Standards.
What are Galvalume sheets?
A hot-dip coating with nominal composition of 55 percent aluminium, 1.6 percent silicon, balance zinc and incorporating minor addition of control elements.. The coating gives the sheet strong corrosion resistance, high heat reflectivity, and good formability, which is why it is widely used for roofing, wall cladding, and structural panels.
The aluminium component forms a corrosion-resistant barrier, while the zinc provides galvanic protection at cut edges and scratches. This self-healing property limits rust spread from points where the coating is broken.
In India, Galvalume sheet is manufactured and certified under IS 15961:2012, the Bureau of Indian Standards specification for hot-dip aluminium-zinc alloy coated steel strip and sheet. The Ministry of Steel has placed this product under a mandatory Quality Control Order, so BIS/ISI certification is required to sell or import it in India.
Galvalume vs. galvanised steel
The difference lies in the coating: galvanised sheet uses a pure zinc layer, while Galvalume uses an aluminium-zinc alloy, which generally performs better for corrosion resistance and heat reflectivity.
For a full breakdown of how Galvalume compares to galvanised steel, see our guide to galvanised and Galvalume steel.
Types of Galvalume sheets
Galvalume sheet is available as plain sheet, corrugated roofing sheet, colour-coated (PPGL) sheet, and coil. The choice usually comes down to cost, finish, and whether the material will be processed further before use.
Plain Galvalume sheets
The base product in the range carries no coating beyond the aluminium-zinc layer. It is the standard choice for industrial and agricultural roofing, where cost and corrosion resistance matter more than appearance.
Corrugated Galvalume roofing sheets
Formed into a wave profile, this format adds rigidity, allowing thinner gauges to span longer distances without sagging. It is the most common choice for pitched roofing on residential and light commercial buildings.
Colour-coated Galvalume sheets (PPGL)
Colour-coated Galvalume, or PPGL, adds a painted or polymer finish over the base coating for UV resistance and a wider colour range. For full specifications, see our guide to pre-painted Galvalume (PPGL) sheets.
Galvalume coils
Coils are supplied in roll form rather than cut sheets, letting fabricators and roll-forming units process them into custom lengths and profiles. Coils suit large-scale or customised production runs rather than direct end use.
Galvalume sheet sizes and specifications
Under IS 15961:2012, Galvalume sheet is manufactured in base steel thicknesses from 0.25 mm to 1.5 mm, with coating applied on top of this base thickness. Sheet and coil widths on the Indian market commonly range from around 600 mm to 1,500 mm, though this varies by manufacturer, grade, and coil-forming line. Length is typically made to order rather than fixed to a single standard size.
Base metal thickness vs. total coated thickness
IS 15961:2025 distinguishes between base metal thickness (BMT), the steel thickness before coating, and total coated thickness (TCT), the thickness after coating is applied. Structural design and ordering should use BMT, since that is what determines the sheet's strength. Buyers comparing quotes across suppliers should confirm which figure a quoted thickness refers to.
Coating classes
IS 15961:2012 defines four coating classes, denoting the minimum coating mass in grams per square metre across both sides of the sheet:
| Coating Class | Minimum Coating Mass (both sides) | Typical Use |
| AZ70 | 70 g/m² | Indoor or low-exposure applications |
| AZ100 | 100 g/m² | Moderate outdoor exposure |
| AZ150 | 150 g/m² | General outdoor roofing (most common grade) |
| AZ200 | 200 g/m² | Coastal, industrial, or high-humidity environments |
In practice, AZ70 and AZ100 suit indoor or low-exposure applications, AZ150 covers most general outdoor roofing use, and AZ200 is specified for coastal, industrial, or high-humidity sites requiring maximum protection.
Steel grades
IS 15961:2025 also grades the base steel by minimum yield strength:
| Grade Designation | Minimum Yield Strength | Minimum Tensile Strength |
| YS250 | 250 MPa | 320 MPa |
| YS300 | 300 MPa | 340 MPa |
| YS350 | 350 MPa | 420 MPa |
| YS450 | 450 MPa | 480 MPa |
| YS550 | 550 MPa | 550 MPa |
Steel grade in this table is a general starting reference. IS 15961:2012 defines the mechanical properties of each grade but does not prescribe grade-by-application rules. Confirm the actual grade for a project through structural calculations for span, load, and wind exposure, in consultation with the fabricator or a structural engineer.
Higher grades are used where a structural application calls for greater load-bearing capacity, such as larger roofing spans or structural panels.
Galvalume roofing applications
Galvalume sheet is used across residential roofing, industrial and commercial buildings, and agricultural structures, with particular strength in hot climates due to its heat-reflective coating.
Residential and commercial roofing
Colour-coated (PPGL) Galvalume is the common choice for homes and commercial buildings, balancing weather resistance with a finished appearance. The coating's heat reflectivity also helps reduce indoor heat gain, a relevant factor across most of India's climate zones.
Industrial and agricultural structures
Plain and corrugated Galvalume sheet is widely used for warehouses, factory sheds, cold storage buildings, and agricultural structures such as barns and greenhouses, where cost efficiency and corrosion resistance take priority over appearance.
Beyond roofing, plain Galvalume sheet and coil are also used in general manufacturing for wall cladding, HVAC ducting, appliance housings, and other fabricated components, wherever a lighter-gauge material needs corrosion resistance and heat tolerance rather than a finished appearance.
Where Galvalume is not recommended
Galvalume performs less reliably in a few specific conditions. Direct contact with concrete, copper, or chemically treated lumber can accelerate galvanic corrosion at the point of contact. Animal confinement structures are also unsuitable, since ammonia from waste decomposition attacks the aluminium in the coating.
In direct, sustained marine exposure, buyers should confirm coating class and installation detailing with their supplier rather than assume a standard grade is sufficient.
Which Galvalume sheet spec suits your application?
Coating class and steel grade only tell half the story. Base metal thickness (BMT) is what determines whether a sheet can handle the span, load, and wind exposure of a specific structure. The table below maps common applications to a starting BMT and coating class range, so buyers can shortlist a spec before requesting a supplier quote.
Application | Recommended BMT | Recommended Coating Class | Why |
| Residential roofing (moderate climate) | 0.30 – 0.45 mm | AZ150 | Balances cost with adequate wind and impact resistance for typical residential spans |
| Commercial roofing | 0.40 – 0.50 mm | AZ150 | Larger spans and higher footfall call for a slightly heavier gauge than residential use |
| Industrial sheds & warehouses | 0.50 – 0.60 mm | AZ150 – AZ200 | Wider spans, machinery vibration, and higher wind loads need a thicker sheet |
| Agricultural structures (barns, greenhouses)* | 0.45 – 0.50 mm | AZ150 | Sustained outdoor exposure without the load demands of industrial spans |
| Cold storage buildings | 0.50 – 0.60 mm | AZ150 – AZ200 | Supports insulated panel systems and copes with sustained internal humidity |
| Coastal, high-humidity & industrial-chemical zones | 0.50 mm and above | AZ200 | Maximum coating mass slows corrosion from salt spray or airborne pollutants |
| Wall cladding & general fabrication (HVAC ducting, appliance housings) | 0.25 – 0.40 mm | AZ100 – AZ150 | Lighter, non-structural use where corrosion resistance matters more than load-bearing strength |
How to choose a Galvalume sheet supplier
A reliable galvalume sheet supplier should provide IS 15961:2025 certification for the batch supplied, a mill test certificate confirming coating class and base steel grade, consistent delivery timelines, and clear warranty terms.
What affects Galvalume sheet prices?
Galvalume sheet prices are driven mainly by base steel thickness, coating class, order quantity, and delivery location, with input costs for steel, aluminium, and zinc fluctuating regularly. Buyers comparing quotes should treat any fixed price as time-bound rather than standard, since these input costs shift on a weekly to monthly basis.
Base metal thickness (BMT): Thicker sheets use more steel and cost more per unit area. Thickness is typically the single largest driver of price difference between two otherwise similar quotes.
Coating class: Higher coating classes such as AZ200 cost more than AZ70 or AZ100, reflecting the additional aluminium-zinc alloy applied per square metre.
Steel grade: Higher-yield-strength grades (YS450, YS550) generally command a premium over standard grades (YS250, YS300) due to the additional processing involved.
Order quantity: Bulk orders typically secure lower per-unit rates than small or retail-quantity purchases, since suppliers factor in processing and logistics overhead per order.
Delivery location: Freight cost to the buyer's site varies by distance from the manufacturing or stocking point, and this is added on top of the ex-factory or ex-warehouse price.
Customisation: Non-standard lengths, widths, or colour finishes can add to cost compared with standard stock sizes.
Because these inputs move frequently, published price figures go stale quickly. Check live Galvalume sheet prices on JSW One MSME for current, location-specific pricing before finalising a purchase order.
What to verify before ordering
Does the supplier provide a mill test certificate for each batch or shipment, confirming coating class and steel grade?
Is BIS/ISI certification under IS 15961:2025 clearly stated and verifiable?
What are the minimum order quantities, and do they suit the project scale?
What lead times does the supplier commit to in writing?
Does the supplier offer customisation in thickness, width, or length?
What warranty terms apply to coating performance and structural integrity?
Is pricing linked to current market rates rather than a fixed quote that may not reflect input cost changes?
Buyers sourcing at scale should also confirm the supplier's track record on comparable projects and request references or prior delivery documentation before committing to larger orders.
The last word
Galvalume sheet's corrosion resistance, heat reflectivity, and long service life make it a dependable choice for roofing and cladding across residential, commercial, industrial, and agricultural use. Getting the right outcome depends on matching coating class and steel grade to the project's exposure and load requirements, and confirming that a supplier can certify the batch against IS 15961:2012 with a mill test certificate. Buyers who verify these details upfront avoid costly replacement later.
Compare Galvalume sheet specifications and coating grades on JSW One MSME to source certified material for your project.
Key Takeaways
Galvalume sheets are cold-rolled steel coated with an aluminium-zinc alloy (55% aluminium, 43.4% zinc, 1.6% silicon) through a continuous hot-dip process, certified in India under IS 15961:2012.
Four coating classes are defined under IS 15961:2012 — AZ70, AZ100, AZ150, and AZ200 — with higher classes suited to more demanding exposure conditions such as coastal and industrial sites.
Base metal thickness (BMT) ranges from 0.25 mm to 1.5 mm; always confirm whether a supplier quote refers to BMT or total coated thickness (TCT), as the two figures differ.
Galvalume sheet suits roofing, wall cladding, industrial structures, and general fabrication but is not recommended for animal confinement structures or direct contact with concrete, copper, or chemically treated lumber.
When sourcing, verify BIS/ISI certification against IS 15961:2012 and request a mill test certificate confirming coating class and steel grade for each batch supplied.
FAQs
1. What is the difference between Galvalume and galvanised sheets?
Galvanised sheets use a pure zinc coating, while Galvalume sheets use an aluminium-zinc alloy. This generally gives Galvalume sheets better corrosion resistance and heat reflectivity in typical atmospheric conditions. Galvanised sheets remain a viable, lower-cost option for less demanding applications.
2. What standard governs Galvalume sheet in India?
Galvalume sheet manufactured or sold in India is certified under IS 15961:2025, the Bureau of Indian Standards specification for hot-dip aluminium-zinc alloy coated steel strip and sheet. The Ministry of Steel has placed this product under a mandatory Quality Control Order, so BIS/ISI certification is required for legal sale or import.
3. What do AZ150 and AZ200 mean on a Galvalume sheet?
These are coating class designations under IS 15961:2025. The number indicates the minimum coating mass in grams per square metre across both sides of the sheet. AZ150 is a common grade for general outdoor roofing, while AZ200 offers higher coating mass for coastal, industrial, or high-humidity sites.
4. Can Galvalume sheets be painted or colour-coated?
Yes. Colour-coated Galvalume, known as PPGL, applies a paint or polymer finish over the base coating under IS 15965:2012 , adding UV resistance and a wider range of colour and finish options. This is common where visual appearance matters alongside durability.
5. Is Galvalume sheet suitable for coastal areas?
Higher coating classes such as AZ200 perform better in moderately coastal conditions, but the aluminium-zinc coating does not tolerate sustained, direct salt spray well. For sites in direct marine exposure, buyers should discuss coating class and installation detailing with their supplier rather than assume a standard grade is sufficient.
6. What is the difference between base metal thickness and total coated thickness?
Base metal thickness (BMT) is the steel thickness before coating is applied, and total coated thickness (TCT) includes the coating layer. When specified by the purchaser, the ordered thickness shall be the base-metal thickness.
7. Can Galvalume sheets be cut and drilled on-site?
Yes, Galvalume sheets can be cut and drilled using standard fabrication tools. Cut edges should be treated or sealed where possible, since the coating's galvanic protection at exposed edges works better when raw edges are minimised.
8. Does JSW One MSME supply Galvalume sheets and coils?
JSW One MSME offers Galvalume sheets and coils across multiple steel grades and coating classes. Buyers can check current specifications, certification, and delivery timelines for their location directly on the platform before placing an order.