Cladding Works — Aluminium Composite & Solid Panel

In practice

The core specification is not a detail. It is the first question.

Aluminium composite panel is two thin aluminium skins bonded to a core, and everything about how that panel behaves in a fire depends on what the core is made of. Polyethylene cores are combustible; mineral-filled and fire-rated cores are not, to varying degrees. Following high-profile facade fires internationally and in the region, requirements across the UAE have tightened considerably, and specifying the core correctly is now the first decision on any cladding job rather than a line item near the bottom of a quotation. We ask about it before anything else, we specify to what the building and the authority require, and we will not substitute a cheaper core to win a price comparison.

Beyond the core, what most distinguishes good cladding from bad is the cavity behind it. Composite panel is a rainscreen, not a waterproof layer: it takes the wind and the sun and sheds most of the water, while the actual weather line is the substrate behind it. That only works if the cavity is ventilated and drained, so anything that gets past the joints can run down the back of the panel and out at the bottom. Sealing the joints and closing off the cavity — which looks tidier and is quicker — traps moisture against the substrate, and that is how a cladding system becomes a damp problem instead of a solution to one.

Fabrication quality shows up in the panel edges. A cassette panel is made by routing a V-groove into the back of the sheet and folding the edges to form a tray, which is then hung on the subframe. The routing depth has to leave exactly the right thickness of skin at the fold — too deep and the fold cracks in service, too shallow and the return will not sit square. Across a long elevation, inconsistent folding reads immediately as a wavy shadow line along the panel joints, which is why we route and fold in our own workshop rather than buying in finished cassettes.

Finally, the subframe. Aluminium expands and contracts noticeably across a UAE summer, so panels have to be hung on fixings that let them move: fixed points and sliding points, not everything bolted rigid. A panel restrained at every fixing will oil-can and buckle visibly in the heat, and that distortion is permanent — you cannot flatten it back out. Panel flatness comes from the subframe and from allowing movement, never from the panel itself.

Composite panel is a rainscreen, not a waterproof layer. Seal the cavity shut and you have made a damp problem.