Fire Rating
Fire performance & NCC compliance
Sketch Australia's surface materials are independently fire tested in Australia, by laboratories accredited by NATA to ISO/IEC 17025, using the test methods the National Construction Code recognises. Full test reports are available to specifiers, builders and certifiers on request.
Flexible Tiles achieve Group 1
Sketch Australia's flexible tile range has been tested and assessed as Group Number 1 — the highest classification available under AS 5637.1-2015 — following independent testing at a NATA-accredited Australian laboratory in September 2026.
Group 1 is the best-performing of the four NCC groups. Materials in this group show the slowest contribution to flashover in a room fire, and are accepted as internal wall and ceiling linings across the widest range of building classes and locations permitted under the Code, including areas where Groups 2 and 3 are not.
The tested material also recorded an average specific extinction area of 88.2 m²/kg, comfortably inside the 250 m²/kg figure the NCC accepts for buildings without sprinkler protection — so the smoke provision does not restrict its use where it applies.
Verified results
| Product | Group Number | Smoke (avg. SEA) | Tested |
|---|---|---|---|
|
Flexible Tiles Modified clay (MCM) flexible tile |
Group 1 | 88.2 m²/kg | September 2026 |
|
Natural Stone Veneer Thin flexible stone veneer |
Group 3 | 326.4 m²/kg | September 2023 |
Group Numbers determined in accordance with AS 5637.1-2015, at Australian laboratories accredited by NATA to ISO/IEC 17025. Group Numbers apply to internal wall and ceiling linings under NCC Volume One, Specification 7. Full test reports, including laboratory details and report numbers, are provided on request.
Test detail — Flexible Tiles
| Tested product | Sketch Flexible Tile — Travertine (MCM flexible tile), tested as representative of the flexible tile range |
|---|---|
| Standard | AS 5637.1-2015 — determination of fire hazard properties, wall and ceiling linings |
| Laboratory | Independent Australian testing laboratory, accredited by NATA for compliance with ISO/IEC 17025 |
| Date tested | September 2026 |
| Group Number | 1 |
| Average specific extinction area | 88.2 m²/kg (mean of three specimens) |
| Average heat release rate | 49.6 kW/m² (mean of three specimens, 50 kW/m² irradiance) |
| Nominal thickness | 3 mm |
| Nominal mass per unit area | Approx. 4,500 g/m² |
| Tested substrate | Specimens adhered to 10 mm plasterboard with a proprietary wallcovering adhesive |
| End use tested | Internal wall and ceiling lining |
What a Group Number means
Where it applies
NCC Volume One clause C2D11 requires the fire hazard properties of internal linings in Class 2 to 9 buildings to comply with Specification 7, and Table S7C4 sets the Group Number for each class and location — apartments, hotels and motels, offices, retail, health care and aged care, schools and assembly buildings. Class 1 housing does not carry these requirements.
How the groups rank
In the reference room fire test, a Group 1 lining does not reach flashover across the full 20-minute exposure. Group 2 reaches it after the first 10 minutes, Group 3 between 2 and 10 minutes, Group 4 within 2 minutes. Lower is better; Group 4 is not permitted as a lining anywhere in a Class 2–9 building, and Group 1 carries the fewest restrictions.
The smoke criterion
Where a building is not protected by a sprinkler system, Specification 7 also requires the lining to meet either a smoke growth rate index of 100 or less, or an average specific extinction area below 250 m²/kg. The flexible tiles measured 88.2 m²/kg.
Evidence of suitability
A report from an Accredited Testing Laboratory is an accepted form of evidence of suitability under NCC Volume One clause A5G3. We supply the full report for your project file — reproduced in full and unaltered, as the laboratory requires.
Scope and limitations
- Internal wall and ceiling linings. The Group Number applies to this end use. It is not a flooring classification — floor coverings are assessed separately for critical radiant flux under AS ISO 9239.1 (Specification 7, S7C3).
- Not a non-combustibility or facade classification. A Group Number does not demonstrate compliance with the NCC's external wall or non-combustible construction provisions — non-combustibility is determined under AS 1530.1 (C2D10) and external wall systems under AS 5113. Talk to us before specifying any Sketch product on an external wall of a Type A or Type B construction building.
- Substrate matters. The specimens were tested adhered to 10 mm plasterboard. Where a project uses a different substrate or adhesive, confirm the build-up with us before it is specified.
- The natural stone veneer is a separate classification. It is Group 3, with an average specific extinction area of 326.4 m²/kg — above the 250 m²/kg figure that applies to buildings without sprinkler protection. Check the report against your building class before selecting it.
- Australian classifications only. NCC Group Numbers and AS 5637.1 do not carry to projects outside Australia. We can supply the test report, but we make no claim of compliance with overseas codes.
- Test results describe behaviour under test conditions. A single test method is not a full assessment of fire hazard under all fire conditions, and these results are not the sole criterion for assessing performance in a real fire.
Need the documentation?
We hold the full test reports and provide them on request for project files, specifications and certifier review — supplied complete and unaltered, with the laboratory's details and report numbers. Tell us the project, the building class and the substrate, and we will send the right report with it.
Specifying on a commercial project?
Send us the project, building class and substrate. We will confirm the applicable classification, supply the full test report for your file, and provide samples for the finish you are considering.
Talk to our technical team