Cladding, Canopies and External Screens: A Facade Inspector's Guide
How a BCA Competent Person carries out cladding inspection in Singapore — ACP, stone, GRC and metal cladding, canopy and external-screen defects, fixings and remedies.
When an aluminium composite panel (ACP) detaches from a 20-storey facade, it tends to do so quietly until the moment it doesn't. Cladding is non-structural by design, but a non-structural panel is still a heavy, sharp object travelling at terminal velocity by the time it reaches a pedestrian. A proper cladding inspection — covering panels, fixings, canopies and external screens — is what the BCA periodic facade inspection regime exists to enforce.
What cladding is, and why it fails
Cladding is an extra non-structural skin added to a building for thermal insulation, weather resistance, acoustic control, fire compartmentation, privacy and aesthetics. The Singapore inventory of facade cladding includes aluminium (solid and composite), stainless and enamel steel, stone (natural and manufactured), glass-fibre reinforced concrete (GRC), uPVC, timber and weatherboard.
A cladding system has four parts the inspector must individually assess:
- The panel itself (material and finish)
- The sub-frame and fixings (steel support, brackets, anchors)
- The weather seal (sealant, gasket or open joint with WRB behind)
- Insulation and any concealed accessories
Aluminium cladding — solid and composite
Aluminium is the most common cladding in Singapore because it is light (~⅓ the density of steel), corrosion-resistant, formable and recyclable. Solid aluminium panels are typically 2–6 mm thick and finished with one of:
- PVDF (polyvinylidene fluoride) — fluorocarbon coating with high fade and abrasion resistance; recommended for external use
- Powder coat — durable but less UV-stable for harsh exposure
- Anodised — electro-chemical finish, durable, low maintenance
ACP cladding inspection — what to check
Conventional ACP is a polyethylene (PE) core sandwiched between two aluminium skins. The panel is light, flat and weather-resistant. The catch is fire performance: ACP with a 100% PE core does not meet SCDF's fire rating requirements, which is why fire-retardant ACP with a mineral core (predominantly magnesium oxide and aluminium hydroxide, achieving Class A2 to EN 13501) has become the specification of choice. Inspectors increasingly need to verify what is actually on the wall and whether the panel composition meets the Fire Code that applied at the time of installation.
Beyond the panel itself, an ACP inspection covers:
- Vertical and horizontal joint detailing — face seal versus open joint
- Sub-frame steel for corrosion at fixings
- Bracket condition — particularly behind concealed joints
- Sealant or gasket performance at every panel-to-panel interface
Sealants and gaskets — where weather seal lives or dies
The weather seal is almost always where ageing cladding starts to fail. Common gasket materials include santoprene, silicone, EPDM and neoprene; common sealants include silicone, polyurethane, polysulphide and acrylic. Silicone is generally the strongest performer for external use — durable beyond 20 years and largely unaffected by UV.
A cladding inspection should treat the following as red flags:
- Visible ageing, hardening or chalking of sealant
- Cohesive failure (crack within the body of the sealant)
- Adhesion failure (sealant lifting from substrate)
- Substrate failure at the bond line
- Three-sided adhesion (sealant bonded to back of joint, indicating missing backer rod)
- Improper width-to-depth ratio — recommended T/D of 2:1 with minimum depth of 6 mm
Most sealant failures trace back to one of seven causes: ageing beyond service life, wrong sealant for the substrate, inadequate surface preparation, excessive joint movement, early movement during cure, improper application, or sealant–substrate incompatibility.
Stone cladding — pin, kerf and undercut anchors
Stone cladding is the most expensive facade and the most punishing to inspect. Natural stone (granite, limestone, sandstone, marble, slate) and manufactured stone veneer are typically attached using one of four fixing methods: dowel/pin, kerf, undercut anchoring or direct fixing. Panel thickness is dictated by stone strength, panel size, wind loading, fixing location in the stone and fixing type.
The defect set on stone cladding includes cracks across panels, misalignment of panels (a sign of detached or missing fixings), spalling at pin locations, signs of epoxy where mechanical anchorage was specified, and corroded fixings or brackets behind the panel. A borescope is the inspector's best friend here — it lets you see the bracket without removing the panel.
Canopies, roof eaves and external soffits
Canopies are single-storey shelters, free-standing or tied back; awnings are attached to the building. Eaves and external soffits — typically wood, gypsum, vinyl, fibre cement, aluminium honeycomb or mineral fibre — sit at the boundary between facade and roof and trap moisture in ways the inspector must look for. Roof materials in scope range from metal (aluminium, stainless, zinc, zincalume, copper, titanium) to clay/cement tiles to polycarbonate, PVC and acrylic.
A canopy inspection should specifically verify:
- Anchor bolt and base plate condition (corrosion at washers and brackets is a recurring finding)
- Bracket replacement compatibility (bi-metallic galvanic corrosion at mismatched fasteners)
- Integrity of any back-of-canopy waterproofing
External screens and green walls
External screens — mesh, perforated metal, woven wire, louvres — are mounted on metal sub-frames bolted into the structural wall. The defects to look for are loose or corroded fixings, dented or torn screens, and bracket fatigue. For green walls, the trio of soil, fertiliser and continuous moisture is aggressive on metal, so stainless steel is the right structural support material; carbon-steel frames will accelerate to corrosion much faster than the rest of the cladding around them. A Professional Engineer must verify the substrate's loading capacity before any green-wall planting starts.
Common defects and red flags
- ACP panels with non-fire-retardant PE core in fire-rated zones
- Hardened, cracked or debonded sealant at panel joints
- EPDM or silicone gaskets that have lost compression
- Corroded sub-frame, brackets or fixings behind cladding
- Stone panels misaligned, cracked or spalled at pin locations
- Open joints where the WRB behind has aged and is letting water through
- Galvanic corrosion at mismatched fasteners
- Loose, dangling or rusted external screens and louvres
- Canopy anchor bolts with rusted washers or base plates
- Green-wall frames with chloride/fertiliser-driven corrosion
Singapore regulatory context
External cladding sits inside three regulatory perimeters:
- The BCA periodic facade inspection regime under the Building Control Act (defects, fixings and falling-object risk)
- The SCDF Fire Code 2023 for combustibility, flame spread (BS 476 Pt 7) and fire propagation (BS 476 Pt 6)
- The Workplace Safety and Health Act for any access work at height
Class 1 or 2 fire rating is the requirement most projects specify; ACP composition must meet the Code in force at design.
How Ezzogenics supports cladding projects
Ezzogenics provides the access and trades for cladding survey, repair and replacement. Our work-at-height team operates gondolas, MEWPs, suspended scaffolds and rope access for cladding inspection support and panel replacement. Our glass and metal works division fabricates replacement sub-frames, brackets and panels — including ACP, aluminium and stainless steel — and handles re-anchoring at corroded fixings. Browse the project portfolio for examples or contact us for a survey.
Sources & references
- BCA — Periodic Facade Inspection (PFI) and Building Control (Periodic Inspection of Buildings and Building Facades) Regulations 2021. www1.bca.gov.sg
- MOM — Workplace Safety and Health Act 2006 and subsidiary regulations. www.mom.gov.sg
- SCDF — Code of Practice for Fire Precautions in Buildings, 2023 Edition. www.scdf.gov.sg
- IES Academy — Certificate in Façade Inspection course material on cladding and canopies.
- BS 476 Parts 6 & 7 — fire propagation and surface spread of flame.
- EN 13501 — fire classification for construction products.
Download the PDF version: Blog_3_cladding-inspection-singapore.pdf