ACP Cladding Installation Process in India (Step-by-Step Guide)

ACP Installation: Where Most Problems Start

ACP cladding looks simple to install — that's why general contractors think they can handle it. The reality is that 80% of ACP facade failures we're called to fix trace back to three things: wrong sub-frame design, incorrect panel routing depth, and silicone applied in the wrong weather conditions. This guide walks through the correct process.

Stage 1: Sub-Frame Design and Installation

The sub-frame is the invisible skeleton your ACP panels depend on for the next 20 years:

• 1.Material: always aluminium (typically 6063-T5 or T6) for external applications. GI (galvanised iron) sub-frames are common in cheap quotes — they corrode at bolted connections within 3-5 years in Indian conditions.
• 2.Horizontal channels (transoms) and vertical posts (mullions) form a grid. Spacing is determined by ACP panel size — typically 600mm × 600mm to 1,500mm × 1,000mm.
• 3.All anchor points are set from a total station or plumb bob survey. A sub-frame that's not plumb produces visible waves in the finished facade.
• 4.Connections to the RCC structure use chemical anchors (Hilti HY-200 or equivalent). Pull-out tests on 10% of anchors are essential.
• 5.All sub-frame connections are stainless steel hardware — galvanised fasteners corrode in the bi-metal junction with aluminium.

Stage 2: Panel Fabrication

ACP panels are fabricated in the workshop before arriving on site:

• 1.CNC routing: grooves are cut on the back face at the bend lines. Critical depth: 1.5× the aluminium skin thickness. Under-routed panels crack at the bend; over-routed panels are weak.
• 2.Bending: panels are folded on a press brake to form a U-channel return edge. This stiffens the panel and provides the mechanical fix points.
• 3.Drilling: rivet holes for hidden-clip or visible-rivet fixing are drilled at exact positions.
• 4.Surface protection film remains on until installation — never remove it in the factory.

Stage 3: Panel Installation

Two main fixing methods are used in India:

• 1.Visible Rivet/Screw Fix: panels are fixed through face with coloured rivets or screws matching the panel colour. Faster and slightly cheaper. Widely used for commercial buildings.
• 2.Hidden Clip Fix (Cassette System): panels have bent returns that hook onto extruded clips on the sub-frame. No visible fixings — clean architectural appearance. Preferred for premium facades.
• 3.In either system, panels are not installed touching each other — a gap of 8-12mm is maintained for silicone weathersealing and thermal movement.
• 4.Panel alignment is checked with a spirit level and string line after every 3-4 panels. Correcting misalignment after silicone is applied is expensive.

Stage 4: Silicone Sealing

The most critical quality step — and the most commonly rushed:

• 1.Joints are cleaned with IPA (isopropyl alcohol) to remove dust and release agents from the panel face. Any contamination causes sealant bond failure.
• 2.Backing rod (polyethylene foam) is inserted to the correct depth — this controls sealant depth and prevents three-sided adhesion.
• 3.Silicone is applied in one continuous run per joint without stopping. Joins within a run create potential leak points.
• 4.Tooling is done immediately — sealant is pressed into the joint and tooled to a concave finish while still wet.
• 5.Temperature: silicone should not be applied below 5°C or above 35°C, or in direct rain. This is routinely violated on pressured Indian construction sites.
• 6.Curing time: 24-48 hours before exposing to rain. Rushing this causes adhesion failure.

Stage 5: Quality Check and Handover

• 1.Full visual inspection — check for panel waves, silicone voids, colour consistency, and any surface damage.
• 2.Hose test: run a hose at the top of the facade and verify no water ingress at joints.
• 3.Protection film removal: done last, after all other trades have cleared the area. Scratches from other trades are the most common defect at handover.
• 4.As-built documentation: panel layout drawing, material test certificates (fire rating, PVDF coating), and sub-frame anchor test reports.

Realistic Installation Timeline

For a mid-size commercial building with 3,000–6,000 sq ft of ACP facade: Sub-frame installation 2-3 weeks. Panel fabrication 2-3 weeks (parallel). Panel installation 3-5 weeks. Silicone sealing 1 week. Testing and punch list 1 week. Total: 7-11 weeks from contract. Fine Glaze provides a Gantt chart with milestones at project start. Call +91 8369233566 for a quotation.