Solid Aluminium Panel — Specification and Use

What it is

A single sheet of aluminium alloy, folded into a cassette and hung on a sub-frame. Unlike ACP there is no polymer core and no bonding line — the panel is one material through its whole thickness.

That single fact drives most of the specification decisions around it.

Specification at a glance

Property	Typical specification
Alloy	3003, 3105 or 5005 to IS 737
Thickness	2mm — 4mm for cassette cladding
Finish	PVDF coil coating, or anodised
Coating standard	AAMA 2605 for the highest weathering class
Fire classification	A1 / non-combustible to EN 13501-1
Panel format	Cassette with folded returns, rear stiffeners as required

Why it gets specified

Fire performance is not a discussion. The panel is metal through its section, so there is no core grade to argue about, no test certificate to match against a delivered batch, and no substitution risk at supply stage. On high-rise, healthcare and high-occupancy buildings this removes the single most contested item in a facade submission.

It holds a fold. Deep returns, sharp corners, tapered panels and curved geometry are achievable in solid sheet in ways a composite panel resists, because there is no core to delaminate at a tight radius.

Flatness. On a prestige elevation viewed in raking light, a well-detailed solid aluminium cassette with rear stiffeners reads flatter than most alternatives.

What drives the cost

Sheet thickness · alloy · finish class, with PVDF and anodised costing more than polyester · panel size and the number of folds · rear stiffener extent · whether panels are flat, curved or tapered · sub-frame complexity · building height and access.

Solid aluminium typically lands above ACP and below most natural stone per square metre, but the gap narrows once ACP is specified in A2 grade.

Where projects go wrong

• Thin sheet on a large panel. The result is oil-canning — visible waviness that no amount of site adjustment removes. It is a design error, fixed at panel-size and stiffener stage, not on site.
• Stiffeners bonded with the wrong adhesive. A facade in Indian summer sun runs far hotter than ambient. The bond must be rated for that service temperature or stiffeners debond and the panel bellies out.
• Assuming a non-combustible panel makes a compliant facade. It does not. Cavity barriers and insulation grade still govern.
• Leaving the finish class unnamed. "Powder coated" spans products lasting five years and products lasting twenty-five. Name the resin class.

Standards referenced

Sheet alloy and temper under IS 737. Reaction-to-fire classification to EN 13501-1. High-performance organic coating performance to AAMA 2605.