What materials make an aluminum suspended ceiling fire rated?

Fire-rated aluminum suspended ceilings combine non-combustible aluminum panels with specialized fire-resistant components. The primary ceiling face uses high-grade aluminum alloy (typically 0.7–1.2 mm thick), chosen for its inherent non-combustibility and dimensional stability under heat. To inhibit flame spread and heat transfer, an intumescent coating is applied beneath each panel; when exposed to elevated temperatures, it expands into a charred foam that seals gaps and insulates the underlying structure. Behind the visible aluminum layer, mineral wool or ceramic fiber blankets absorb heat energy and prevent temperature rise in the plenum. Above the suspension grid, fire-rated gypsum or calcium silicate boards create a continuous barrier, tested to ASTM E119 or EN 1365 standards. Edges and panel joints are sealed with fire-stop sealants, while thermal fusible links in suspension clips activate at preset temperatures, collapsing to close cavities. Together, these materials and accessories form an integrated assembly that achieves its specified fire rating.