Flooring Fire Ratings in Australia NCC Compliance Guide
Under Australia's National Construction Code (NCC) 2025 Volume One, flooring in Class 2 to 9 buildings must meet specific fire hazard property requirements, tested under AS ISO 9239.1. This guide explains what Critical Radiant Flux (CRF), Smoke Development Rate, and Group Number mean for your flooring specification, and how to confirm NCC Specification 7 compliance from a fire test report.
Fire ratings for flooring explained
In Australia, The National Construction Code (NCC) 2025 Volume One - Section C Fire resistance - Specification 7 Fire hazard properties define the fire hazard property requirements for flooring in Class 2 to 9 buildings. These buildings encompass various types, including offices, retail spaces, and healthcare facilities. The fire rating of flooring is determined by the values from the AS ISO 9239.1-2003.
The fire test methods for flooring and wall lining
AS ISO 9239.1:2003 (floor)
The AS ISO 9239.1:2003 is the test method standard for assessing the Reaction to fire tests for floorings.
Measuring:
- Critical Radiant Flux (CRF): Also referred to as Critical Heat Flux (CHF in kW/m²), this determines the minimum heat required to sustain flame spread.
- Smoke Development Rate: Measured in %.min, this evaluates the amount of smoke generated during combustion.
The result from this test are then used to determine compliance with the NCC Fire Hazard properties that sets out the requirements of these materials.
AS 5637.1 (wall)
The AS 5637.1 is the fire test method for determination of fire hazard properties wall and ceiling linings. Applicable to floor covering that is continued more than 150 mm up a wall.
Measuring:
- Group number: Rating from Group 1 to 4.
- Average specific extinction: Measured in m²/kg, relevant for buildings not fitted with a sprinkler system and needs to comply with an average specific extinction area less than 250 m²/kg.
NCC 2025 Fire hazard for flooring requirements
| Class of building | Building fitted with a sprinkler system* | Fire-isolated exits and fire control rooms |
| Class 2, 3, 5, 6, 7, 8 or 9b, excluding Class 3 accommodation for the aged and Class 9b as specified below | 1.2 kW/m² | 2.2 kW/m² |
| Class 3 accommodation for the aged | 2.2 kW/m² | 4.5 kW/m² |
| Class 9a patient care areas | 2.2 kW/m² | 4.5 kW/m² |
| Class 9a areas other than patient care areas | 1.2 kW/m² | 4.5 kW/m² |
| Class 9b auditorium or audience seating area used mainly for indoor swimming or ice skating | 1.2 kW/m² | 2.2 kW/m² |
| Class 9b auditorium or audience seating area used mainly for other sports or multi-purpose functions | 1.2 kW/m² | 2.2 kW/m² |
| Class 9c resident use area | 2.2 kW/m² | 4.5 kW/m² |
| Class 9c areas other than resident use areas | 1.2 kW/m² | 4.5 kW/m² |
In addition, for buildings not protected by a sprinkler system, a maximum smoke development rate of 750% per minute; and for any portion of the floor covering that is continued more than 150 mm up a wall needs to comply with a group rating in Table S7C4 and have an average specific extinction area less than 250 m²/kg.
*Reproduced from NCC 2025 Specification 7. Whilst the information in this guide was accurate at the time of publication, it is the users’ responsibility to confirm alignment with current standards and/or building codes. Always refer to the National Construction Code website.
Rule of thumb for NCC 2025 (Specification 7C3): If the Critical Radiant Flux (CRF/CHF) >4.5 kW/m² and the Smoke Development Rate <750%.min, generally complies in Class 2 to 9 buildings with or without sprinklers.
Visual guide for fire hazard properties standard for flooring
Understanding National Construction Code (NCC) fire safety requirements for flooring can be complex but we’ve made it simple.
Our visual and easy-to-follow guide breaks down fire rating requirements by area, helping you quickly identify the right flooring solutions for fire safety compliance.
✅ Clear, visual format for easy reference
✅ Breakdown by area to simplify compliance
✅ The go-to resource for architects, designers, and builders
Download the visual guide
Frequently asked questions
Q: What is the fire rating requirement for flooring in Australia under the NCC?
Under NCC 2025 Volume One Specification 7 Fire hazard properties, flooring in Class 2 to 9 buildings in Australia must meet the following fire hazard property requirements referenced in the:
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