Fibre Reinforced Facade Encyclopedia: Materials
Composite cladding is any external wall panel made from two or more distinct materials bonded together so that the finished product behaves differently from either constituent on its own. The category is defined by construction rather than by chemistry, so it spans metal skins over a plastic or mineral core, glass fibre in cement, glass fibre in resin, cellulose in cement, and timber flour in polymer. The only useful way to compare them is by the two properties the rest of the design depends on: weight per square metre and the fire compliance pathway the product can take.
Composite cladding is not one material with one behaviour. At 4 mm thickness an aluminium composite panel weighs about 5 kg per square metre and a glass fibre reinforced concrete facade panel weighs about 40. Their fire pathways are equally far apart, and nothing about the word composite tells you which is which.
At a glance
| Property | Typical value | Note |
|---|---|---|
| Aluminium composite panel, polyethylene core | about 5.5 kg/m² at 4 mm | Combustible under AS 1530.1; removed or restricted across Australia and the UK |
| Aluminium composite panel, mineral filled FR core | about 7 kg/m² at 4 mm | Roughly 70% mineral filler; most grades still test as combustible |
| Aluminium composite panel, A2 core | 7 to 8 kg/m² at 4 mm | About 90% mineral filler; EN 13501-1 A2-s1,d0 where the specific panel is tested |
| Fibre cement composite | 12 to 20 kg/m² at 8 to 12 mm | Cement and cellulose; fibre reinforced cement sheeting is named in the NCC |
| Glass fibre reinforced concrete | 30 to 50 kg/m² | Cementitious; AS 1530.1 Not Deemed Combustible where the product is tested |
| Fibre reinforced polymer | 5 to 32 kg/m² | Polymer matrix; reaction-to-fire plus full-scale AS 5113 pathway, never non-combustible |
| High pressure laminate | 8 to 11 kg/m² at 6 to 8 mm | Kraft paper in thermoset resin; combustible, typically EN 13501-1 Class B or C |
| Wood polymer composite | 10 to 16 kg/m² | Timber flour and polyethylene or PVC; combustible, low-rise use |
| Metal faced sandwich panel, mineral wool core | 12 to 25 kg/m² | Steel or aluminium skins; core and adhesive both govern the fire result |
| Substructure allowance | 5 to 15 kg/m² on top of any panel above | Rails, brackets, cavity barriers and fixings |
What counts as composite cladding
The defining feature is a bond. A composite panel is manufactured as a single unit in which the layers or phases cannot be separated on site, so the panel is specified, tested and certified as one product. A rainscreen built from a metal tray, a mineral wool batt and a breather membrane is an assembly of separate products, not a composite; a 4 mm sheet of aluminium bonded either side of a polymer core is a composite, and it carries one test report covering the whole thing.
That distinction matters because test results attach to the bonded product. A reaction-to-fire result for a composite panel says nothing about the individual layers, and the layers say nothing reliable about the panel, which is why a submission has to name the exact panel, core and thickness rather than the material family.
The families in use
Three constructions cover almost all architectural work. Metal skinned panels place thin aluminium or steel over a core, and the core does the load sharing and sets the fire behaviour. Fibre reinforced cementitious panels, principally glass fibre reinforced concrete and fibre cement, disperse short fibres through a cement matrix so the section can be thin without steel reinforcement and its cover. Fibre reinforced polymer laminates place glass fibre in a cured thermoset resin, giving the highest strength for the lowest weight and the widest geometric freedom.
A fourth group, decorative laminates and wood polymer composites, is common on low-rise and internal work and rarely appropriate where the external wall has to be non-combustible.
Choosing between them
- Dead load: from about 5 kg/m² for a thin polymer laminate or a 4 mm metal composite up to 50 kg/m² for glass fibre reinforced concrete. Anything above about 50 kg/m² is no longer lightweight cladding and starts sizing the structure behind it
- Span between supports: metal composites and fibre cement are sheet products fixed at close centres; glass fibre reinforced concrete spans further through ribs or a stud frame; fibre reinforced polymer spans furthest because shape, not thickness, provides the stiffness
- Geometry: flat and simple folds suit metal composites and sheets; single and double curvature suit moulded cementitious and polymer composites, where the mould is the tooling cost rather than the panel
- Fire pathway: cementitious composites can take the Deemed-to-Satisfy route where tested; polymer and metal composites with organic cores cannot and need a Performance Solution
- Cost band, qualitatively: metal composites and fibre cement are the low band on flat repetitive elevations; glass fibre reinforced concrete is the middle band and improves as mould reuse rises; fibre reinforced polymer is the upper band on small quantities and closes the gap when the geometry is complex or the weight saving removes structure
Repetition moves composite cladding costs further than any other variable. Sheet products are priced by area and barely care how many panel types there are. Moulded composites are priced by mould, so twenty identical panels from one mould and twenty unique panels from twenty moulds are entirely different projects at the same square metre count.
Fire is the first filter
In Australia, external walls of Type A and Type B construction must be non-combustible under the Deemed-to-Satisfy provisions of NCC 2022 Volume One (check the edition adopted in your jurisdiction). That filter removes every composite with an organic core or an organic matrix before any other comparison is made. Cementitious composites can pass the AS 1530.1 furnace test and satisfy the provisions directly. Fibre reinforced cement sheeting is additionally named in the Code as a material that may be used where a non-combustible material is required.
Every other composite reaches the same wall through a Performance Solution supported by a full-scale AS 5113 test and a fire engineer’s assessment of the specific building. Internationally the same split appears as EN 13501-1 Class A1 and A2 against Classes B to F, and as ASTM E136 against ASTM E84 and NFPA 285.
What a specifier should ask for
- The tested product name, core designation and thickness, matched to what is on the shop drawings
- The AS 1530.1 report where non-combustibility is claimed, or the AS 5113 full-scale report where it is not
- Core filler content by mass for any metal skinned panel, stated by the manufacturer rather than inferred from a trade name
- Weight per square metre for the panel and separately for the substructure, so the dead load allowance is complete
- Evidence of factory production control and third party certification linking the delivered batch to the tested sample
- A sample or visual mock-up, because composite surfaces are produced by very different processes and do not weather alike
Standards and references
- AS 1530.1 (combustibility) and AS 1530.3 (early fire hazard indices)
- AS 5113 (full-scale facade fire test) and NCC 2022 Volume One C2D10, C1V3 and Specification 7
- EN 13501-1 (reaction to fire classification) and EN ISO 1182 (non-combustibility)
- BS 8414 with BR 135 (UK full-scale facade test)
- ASTM E136, ASTM E84 and NFPA 285 (US combustibility, flame spread and full-scale wall tests)
- AS 4284 (building facade testing) and AS/NZS 1170.2 (wind actions)
- AS 1170.1 for dead load allowances on supporting structure
Related terms
Questions specifiers ask
Is composite cladding banned in Australia?
No. The category is far too broad for a blanket ban. What is restricted is aluminium composite panel with a polyethylene core, which several states prohibited on classes of building from 2018 onward. Cementitious and fibre cement composites remain fully compliant where tested.
Which composite cladding is non-combustible?
Only the cementitious ones, and only when the specific product has been tested. Glass fibre reinforced concrete can achieve a Not Deemed Combustible result under AS 1530.1, and fibre reinforced cement sheeting is named in the NCC. Metal composites with organic cores and all polymer composites cannot pass the furnace test.
How much does composite cladding weigh?
From about 5 kg per square metre for a 4 mm aluminium composite panel or a thin polymer laminate, up to 50 kg per square metre for glass fibre reinforced concrete. Add 5 to 15 kg per square metre for rails, brackets and fixings.
What is the difference between composite cladding and a sandwich panel?
A sandwich panel is one type of composite, built as two structural skins bonded to a lower density core. Composite cladding also includes materials where the phases are dispersed rather than layered, such as glass fibre in cement or in resin.
Can composite cladding be used above 18 metres?
It depends on the compliance pathway, not the height alone. A cementitious composite with an AS 1530.1 pass can be used on the Deemed-to-Satisfy route. A combustible composite needs a Performance Solution with an AS 5113 test result and a fire engineer’s assessment for that building.
Does a fire test on one composite panel cover the range?
No. The result belongs to the tested panel, core and thickness. Changing the core grade, the skin, the bonding adhesive or the panel thickness invalidates the result, which is why submissions are checked against the report rather than against the brochure.
Comparing composite cladding options on weight and fire pathway? ShapeShell-RC is our glass fibre reinforced concrete system with an AS/NZS 1530.1 result of Not Deemed Combustible from Ignis Labs, and ShapeShell-RT is our FRP system with a full-scale AS 5113 pass at BRE Global. See ShapeShell fire test data
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.