Cladding changes the appearance of a building faster than almost any other work. It is also among the most expensive things to get wrong: if the sub-frame and drainage behind the panels are badly detailed, the problem appears years later and can only be fixed by taking the façade off again.
What aluminium composite panel actually is
It is a sandwich panel: a core pressed between two thin aluminium skins. That gives lightness and flatness, and it folds and cassettes easily. The critical element is the core, because what the core is made of determines the panel's fire class.
| Material | Where it suits | What to check |
|---|---|---|
| ACP — A2 fire class | Taller buildings and high-occupancy use | Mineral filled, heavier and dearer |
| ACP — class B | Low-rise buildings where regulations allow | Class must appear in the quote and certificate |
| Solid aluminium sheet | Small areas, reveals and detail work | Prone to oil-canning over wide spans |
| HPL / compact laminate | Façades wanting texture or a timber look | Different expansion allowance to ACP |
| Applied film on glazing | Shopfronts and entrance elevations | Film choice matters on insulated glazing |
The sub-frame: the invisible half of a façade
Panels are not glued to the wall. They are cassetted onto a frame of galvanised steel or aluminium profiles whose job is not only to carry the load but to leave a ventilation cavity behind the panel and route condensation downwards.
- Panels need expansion gaps between them; aluminium moves with heat, and closing the gaps makes panels bow.
- Drainage must be left at the bottom of the façade — the cavity should not be sealed shut.
- Where dissimilar metals meet, galvanic corrosion has to be designed out.
- On coastal elevations, fixings should be stainless.
How long does cladding take?
Access, not panel fabrication, drives the programme. A single-storey shopfront reachable from the ground can be finished in a few days, whereas on a multi-storey building the scaffold up and down can account for half the total schedule. Any duration quoted before the height and access method are established is a guess.
Maintenance and lifespan
A well-coated composite façade holds its colour for many years if it is washed regularly. Abrasive cleaners and stiff brushes dull the coating. An annual check of joints and sealant is the cheapest way to keep water out from behind the façade.
Royal Reklam states the panel brand, thickness and fire class in writing in every cladding quote, along with the sub-frame specification and installation method.