Two skins and a core create composite behaviour
An aluminium composite panel generally combines two aluminium cover sheets with a bonded core. Working together, the layers can deliver a flat, relatively stiff surface at low weight for façades, signs, retail interiors and decorative work.
Yet “composite panel” is not one technical specification. Skin gauge and alloy, total thickness, core, coating, reaction-to-fire class, exterior suitability and tolerances vary. For example, 3A Composites describes ALUCOBOND PLUS with aluminium skins and a mineral-filled polymer core, while its A2 range targets a different level of fire performance. Those declarations cannot be transferred to another brand.
Do not treat signboard and façade grades as identical
A sheet for a sign, exhibition stand or interior display faces different demands from a multi-storey façade. Façade panels must be selected for wind, temperature, sunlight, rain, fixings and fire rules, not colour and overall thickness alone.
Ask for the declared application, current technical approval, performance documentation, fire classification, finish conditions and approved installation system. Do not move a sign-grade product to a façade—or any product into a special chemical or hygiene environment—without manufacturer approval.
Fire class cannot be read from colour or the words mineral-filled
Although the skins are aluminium, the core, complete panel and façade build-up all affect fire behaviour. A black, white or mineral-looking core is not proof of classification. Do not call a panel non-combustible or fire-retardant without the current report for the exact product code.
3A Composites publishes different EN 13501-1 classes for its PLUS and A2 products and stresses that wall, insulation, subframe, cavity, layout and fastening all influence the façade. For regulated work, follow the architect, fire consultant, engineer and the approved manufacturer system.
Flatness depends on the subframe too
A flat factory panel can appear wavy on a misaligned or under-designed subframe. Profile alignment, brackets, building movement, cassette returns, support centres and fixings must follow design wind loads.
Check compatibility among aluminium profiles, steel anchors, screws, rivets, adhesives and isolating tapes. Dissimilar-metal contact, trapped water and unprotected cut edges can raise corrosion risk, especially in coastal environments.
Manage thermal movement instead of restraining it
Aluminium expands when heated. Long or dark panels may see larger temperature changes, so holes, fixed and sliding points, joints and clearances must accommodate movement. Over-tightening every fixing or trapping panels without gaps can cause bowing, noise and joint distress.
ALUCOBOND's current fabrication guide likewise requires thermal expansion and tension-free panel movement to be considered. Numerical allowances remain specific to product, panel length, temperature range and system; use the relevant manufacturer's tables.
Protect surface direction, film and fabrication quality
Metallic, brushed and directional finishes may appear different when adjacent panels are rotated. Record arrows and batch references before cutting and keep one orientation. Approve samples and, where colour consistency matters, one production batch.
Protective film is temporary. Remove it in the sequence and period stated by the manufacturer. Use suitable tools for cutting, routing, folding, drilling and riveting; avoid burrs, deep routing, scratches and metal swarf on the finish.
Do not solve every joint with sealant
Ventilated façades, sealed cassettes, bonded systems and sign boxes manage water differently. Heads, sills, corners, parapets and openings must drain as a complete design; sealing intended drainage paths can trap water.
Sealants, tapes, adhesives and cleaners require chemical compatibility with the coating and core. Bonded systems must follow the supplier's preparation, primer, temperature, curing and safety requirements.
Information for a useful quotation
Send the following instead of asking only for a square-metre price:
- Application: façade, sign, interior, soffit or decoration
- Area, panel layout, building height and drawings
- Colour, finish, gloss and directional pattern
- Exact series, total thickness, skin and core requirements
- Required reaction-to-fire class and documents
- Subframe, cassette, joint, fastening and insulation system
- Coastal, sun, wind, chemical and humidity exposure
- Cutting, routing, folding, delivery and installation scope