Fire Hazard Properties – NCC

Engineered for Safety: Fire-Rated Linings That Meet
and Exceed NCC Standards

Understanding NCC fire hazard properties requirements for lining materials

Fire Hazard Properties define how wall and ceiling linings contribute to fire growth and smoke development. Under the NCC, they are classified in accordance with Specification 7 (NCC 2022) using AS 5637.1, based on testing such as AS/NZS 3837 or AS ISO 9705.

A common risk is assuming compliance based on testing that does not reflect the installed system, particularly where joints, gaps or perforations are present.

Compliance must be demonstrated for the system as installed, not the base material in isolation.

View tested SUPAWOOD lining systems and their Fire Group classifications, including configuration details and compliance documentation.

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Fire Group Classification Overview

Fire Hazard Properties are classified from Group 1 to Group 4.

Fire Group	Performance Level	Typical Application Areas Under The NCC
Group 1	Highest Performance	Fire Isolated Exists,
Group 2	High Performance	Public Corridors, Unsprinklered aged care, classroom ceilings
Group 3	Standard Materials	All other areas, e.g. Offices, some commercial areas
Group 4	Not Acceptable	Not Permitted in commercial applications

The required Fire Group depends on building class, occupancy and location within the building. More details here: What Fire Group Number Do I Need?

How Fire Hazard Properties Are Classified

Fire Group classifications are determined in accordance with AS 5637.1, using:

AS/NZS 3837, small-scale testing
AS ISO 9705, full room burn testing

The appropriate method depends on the lining system.

Small-scale testing may apply to flat, continuous materials. Systems with joints, gaps, perforations, slats or complex profiles typically require full-scale testing.

These features can significantly change fire behaviour and must be assessed as part of the installed system.

You can download SUPAWOOD’s certification documentation below here

Work through your specific lining system, fire requirements and compliance pathway with our team.

Schedule a Design Clarity Meeting

Where Compliance Can Go Wrong

Many products are promoted with Fire Group classifications based on flat panel testing.

That classification may not apply when the product is:

Perforated for acoustic performance
Installed with spacing between elements
Configured as slats or battens
Modified from the tested condition

These changes can alter fire behaviour through increased surface area, airflow and heat transfer.

A Fire Group classification only applies to the tested material, component or assembly.

You can download SUPAWOOD’s certification documentation below here

Avoid Specification risk!

Understand which system configurations are compliant.

Download Fire Info Pack

How to Select a Compliant Lining System

To confirm compliance, check:

The required Fire Group for your project
The test method used
The exact configuration that was tested
Whether your design matches that configuration

If these do not align, the classification may not apply.

How SUPAWOOD Supports Fire Compliance

SUPAWOOD lining systems are tested as complete systems, including configuration, substrate and geometry.

This provides:

Alignment between tested and installed conditions
Clear documentation for certification
Confidence during specification and approval

Frequently Asked Questions About Fire Hazard Properties

Fire Group Requirements

What fire group number do I need for my project?

The required Fire Group number depends on the building class, location within the building, and use of the space under the NCC. While most areas can use any of groups 1, 2 or 3 others require the use of 1 or 2. For example fire isolated exits or an unsprinklered public corridor in a hospital require Group 1, and school classroom ceilings require Group 1 or 2.

For a detailed breakdown by building type and application, see:
➞ What Fire Group Number Do I Need?

How do I achieve a Group 1 fire rating?

Achieving Group 1 requires the lining system, not just the material, to be tested and classified in accordance with AS 5637.1, typically using full-scale ISO 9705 room testing. Substrate, finish, perforation, and configuration all influence the result.

A detailed guide to achieving Group 1 across different project types is available here:
➞ How can I reach Fire Group Rating 1 for my school project?

What fire group requirements apply in New Zealand?

New Zealand uses a similar classification system, including Group 1-S requirements, but with differences in terminology and regulatory framework under the NZBC.

Read more about this here:
➞ Fire Hazard Properties – New Zealand (NZBC)

Compliance and Risk

What makes a lining system compliant under the NCC?

Compliance depends on the tested performance of the installed system, not just the base material. Factors such as spacing, backing, fixing method, and finish all affect classification and must match the tested configuration.

For a detailed explanation of compliant lining systems:
➞ Which Lining Products Are Compliant Under the NCC?

Do perforations, joints or gaps affect fire performance?

A detailed guide to achieving Group 1 across different project types is available here:
➞ Which Lining Products Are Compliant Under the NCC?

Can intumescent coatings be used to achieve fire group ratings?

Intumescent coatings are often tested on flat panels, but that result does not carry over to real lining systems with joints, gaps or perforations. In practice, achieving the tested coating thickness and consistency on site is difficult. This creates a high risk that the installed system will not perform as assumed for compliance.

See why coatings can be problematic here:
➞ What is Wrong with Using Fire Intumescent Paint to Achieve Fire Group Numbers?

Can I rely on CodeMark certificates or fire engineering assessments?

CodeMark and fire engineering reports can support compliance, but they do not replace the need for appropriate test evidence. Building surveyors still require that the system meets NCC performance requirements based on valid and applicable data.

A deeper explanation of their role and limitations is available here:
➞ How reliable are CodeMark Certificates and Fire Engineering Assessments?

What changed under NCC 2019, NCC 2022 and NCC 2025?

Recent NCC updates clarified how lining systems must be tested and classified, with greater emphasis on system-based testing and appropriate application of AS 5637.1. These changes affect how many timber and perforated systems are assessed.

See the full summary of NCC changes here:
➞ NCC 2025 Changes to Timber Panelling: What You Need to Know

Testing and Classification

How are Fire Hazard Properties classified?

Fire Group classifications are determined using AS 5637.1, based on either small-scale or full-scale testing depending on the system.

When is full room burn testing required?

Full-scale testing is required when the lining system includes joints, gaps, perforations, or complex geometries that affect fire behaviour. In these cases, small-scale tests such as AS/NZS 3837 are not sufficient to determine Fire Group classification.

See the full explanation of testing requirements here:
➞ Which Lining Products Are Compliant Under the NCC?

Can AS/NZS 3837 be used for all lining systems?

No. AS/NZS 3837 is a small-scale test and is only suitable for continuous, flat materials without openings or joints. Many architectural lining systems require classification under AS 5637.1 using full room burn testing to meet NCC requirements.

Learn when each method applies:
➞ Which Lining Products Are Compliant Under the NCC?

What is the difference between fire rating, fire resistance and fire retardancy?

These terms are often confused but refer to different measures. Fire resistance relates to how long an element can withstand fire exposure, fire retardancy refers to slowing ignition or spread, and Fire Group classification measures how lining materials allow fire growth.

A clear explanation of these differences is provided here:
➞ Fire Rating, Fire Retardancy or Fire Resistance – What is the Difference?

SUPAWOOD Systems and Documentation

Which SUPAWOOD products meet each Fire Group classification?

SUPAWOOD lining systems have been tested in specific configurations to achieve defined Fire Group classifications. Selection depends on the required group, design intent, and installation conditions.

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Can SUPAWOOD linings be customised without affecting fire compliance?

Customisation is possible, but changes to spacing, perforation, backing, or finishes can alter fire performance. Any variation from the tested system needs to be carefully assessed to ensure compliance is maintained.

See how customisation affects compliance here:

➞ Can I Customise SUPASLAT?

Where can I access fire compliance reports and test certificates?

Compliance documentation, including fire test reports and classifications, should be readily accessible to support design and approval. Having clear documentation helps streamline specification and certification.

➞ Download SUPAWOOD Product Compliance Reports below