Services / ACP & Cladding
ACP is cheap to install and expensive to fix.
ACP is two thin aluminium sheets bonded to a core. It is light, quick to install, and available in any colour. How it ends up performing is decided by the framing behind the panel and by where the water is sent.
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- Agung Sedayu Group
- Pulau Intan
- Jaya Konstruksi
- Wijaya Karya
- PP (Persero)
- Atlas Construction
What is inside an ACP panel
Three layers, and the middle one sets both the price and how the panel behaves in a fire.
ACP, short for aluminium composite panel, is two thin aluminium sheets with a core layer bonded between them. The aluminium is usually 0.3 to 0.5 mm thick, far thinner than most people assume. The core is what makes the panel stiff without making it heavy.
That core can be pure polyethylene or a mineral-filled, fire-resistant mix. Once installed, the two look identical. The difference shows up in a fire: one burns and carries flame up to the floor above, the other does not.
So the first question on any ACP quotation is which core is being offered, and at what height the panels will sit. Colour and finish follow once those two are settled.
Cladding is the broader term for any external covering. ACP is one kind, and the most common in Indonesia because of its price. Solid aluminium — a thick sheet with no core — is the alternative for surfaces that need to read perfectly flat.
What we do on ACP work
On a multi-storey building, ACP usually sits around the glass rather than on its own.
The framing behind it
An ACP panel does not carry wind load by itself across a wide surface. The aluminium framing behind it does, and the spacing of that framing decides whether the surface still reads flat.
Where the water goes
Water always gets through the joints between panels. The cavity behind the panel is designed so that water runs down and back out at a chosen point, before it reaches the wall behind.
The junction with the glass
This is where two systems meet, often from two different suppliers. The detail in the gap between them has to be drawn early, because neither side automatically treats it as theirs.
Flatness
A panel can look rippled even when the panel itself is flat. The usual causes are framing spacing, how the panel edge is folded, and thermal expansion. All three are calculated before panels are ordered.
Finish
A PVDF coating outlasts polyester by a wide margin under Jakarta sun, particularly on a face exposed all day. The price difference is small next to the cost of replacing panels.
Solid aluminium panels
Where a surface must read very flat, or must contain nothing combustible, solid aluminium replaces the composite panel. It costs more per metre, and rarely needs to be used across the whole elevation.
When ACP is not the answer
Some work gets cheaper and safer the moment ACP comes off the drawing.
- Any surface that needs to be seen through. ACP closes it, and the space behind loses its light and its view.
- A high-rise with pure polyethylene-cored panels. At that height the core type stops being a budget question.
- High wind pressure on an elevation whose framing was never calculated to carry it.
- Install-only work, with no detail drawings, and nobody carrying the leak if one appears.
A price per square metre covers the panel and fitting it. The framing behind it, the detail where it meets the glass, and responsibility for a leak all sit outside that figure. If none of those are in your scope, this work does not need us. If they are, the two numbers you are comparing are measuring two different things.
Questions we get asked
Most come from owners comparing quotations.
- What is the difference between ACP and curtain wall?
- Curtain wall carries wind and water as one system and stands in place of the building's wall. ACP is a surface fixed to framing behind it. Many buildings use both, so the real question is which surface gets which. We cover that in full in Insight, including the junction line between them, which needs to be assigned in the work scope.
- How much does ACP cost per square metre?
- It depends on the core type, the aluminium thickness, the finish, and the framing needed behind it. The per-square-metre figures in circulation usually cover the panel and its installation only: no framing, no detailing where it meets the glass, and no responsibility for a leak. We price it after seeing your facade drawings.
- What is fire-retardant ACP, and when is it needed?
- Fire retardant refers to a core mixed with mineral filler so it does not spread flame. Panels with a pure polyethylene core are cheaper and behave very differently in a fire. For high-rise and public buildings, the core type belongs in the specification from the start.
- How long does ACP last?
- It depends on the finish and on how much sun the face takes. A PVDF coating on a fully exposed elevation generally holds its colour far longer than polyester. In practice the sealant at the panel joints usually needs replacing before the panels themselves do.
- Why does installed ACP look rippled?
- The cause is nearly always the framing behind it. Framing spaced too far apart, a folded edge with no stiffener, and thermal expansion all make the surface reflect light unevenly. Once it is installed, fixing it means taking that elevation apart.
Our core team has spent decades calculating and installing high-rise facades.