Non-combustible material

A non-combustible material, in the National Construction Code, is one that meets the non-combustibility test in AS 1530.1 (or sits in one of the NCC’s deemed-non-combustible categories). The AS 1530.1 test places five small cylindrical samples in a furnace at 750°C for 30 minutes; if any sample flames for more than 5 seconds, the material is deemed combustible.

The NCC names several material categories as deemed non-combustible without further testing. Common examples include concrete, masonry, metal, ceramic tiles, fibre cement, plasterboard, and mineral-fibre insulation. Most other materials need an AS 1530.1 test certificate from the manufacturer to be specified as non-combustible.

Non-combustibility is required in specific scenarios for Class 1 and Class 2 buildings:

H3 fire separation: separating walls between Class 1 sole-occupancy units, garage-to-house separation, and townhouse fire walls must use non-combustible linings and barriers in the rated assembly.
H7 bushfire areas: BAL-29 and above generally require non-combustible cladding, eaves, decking, and roofing. BAL-FZ (Flame Zone) limits non-structural external materials to non-combustible only.

Non-combustible is not the same as fire-rated. Fire-rated means an assembly has been tested for a Fire Resistance Level (for example, -/60/60) to limit fire spread for a stated duration. Non-combustible is a property of the material; FRL is a property of the assembly. A timber-framed wall with plasterboard linings can carry an FRL but still contains combustible timber. A single non-combustible sheet has no FRL on its own.

The supplier’s AS 1530.1 test certificate (or the NCC deemed-non-combustible classification) is the documentation to keep for the certifier and the handover pack.

Also known as: non-combustible, AS 1530.1 compliant material.

Category: Fire safety / building materials / NCC compliance.

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