Peter is a licensed builder with over 45 years of experience in the construction industry. In 2012, his expertise in energy efficient construction inspired the invention of ThermaDoor Premium garage door insulation - the original purpose made garage door insulation in Australia.
When it comes to building safety, one of the technical questions we’re often asked is about the fire rating of garage door insulation. People want to know whether products like ThermaDoor Premium need to carry a formal fire rating. The important point is this: garage door insulation does not need a fire rating — but it must be fire-retardant and tested for flammability under the correct Australian Standards.
This distinction exists because the steel garage door itself provides the fire resistance, while the insulation’s role is thermal performance. In this blog, we’ll explain what the standards actually say, why some products promote fire ratings, and how ThermaDoor Premium is the ONLY PURPOSE MADE garage door insulation in Australia and meets the correct compliance requirements.
Australia’s National Construction Code (NCC) sets requirements for fire safety across Australian buildings. Fire ratings, also called Fire Resistance Levels (FRLs), apply to certain building elements such as:
Fire separation walls (between dwellings)
Boundary walls (close to a property line)
Floors and roofs that form part of fire compartments
In these cases, insulation and cladding materials must be tested as part of the system. For example, PIR (polyisocyanurate) is often used in walls and roofs, so they are tested to:
AS 1530.3 – reaction-to-fire indices (ignitability, flame spread, smoke).
AS 1530.4 – fire resistance of building elements (whole wall or roof systems).
This is why PIR products sold as garage door insulation are often marketed with a ‘fire rating’.
Garage doors aren’t walls or roofs – they are covered by AS/NZS 4505:2012 (Garage doors and other large access doors).
Here’s the key difference:
Garage doors are typically constructed from steel, which is non-combustible.
The steel door skin itself provides the fire resistance.
The insulation behind it is a bulk thermal product — its role is comfort and energy efficiency, not structural fire protection.
Unless a garage door is specifically required as part of a fire-rated separation (for example, between a garage and a habitable room), the NCC does not require the insulation to carry a fire rating. In those special cases, the entire door assembly would be tested under AS 1530.4 to achieve an FRL.
ThermaDoor Premium garage door insulation is purpose made for Australian sectional and tilt garage doors. Its compliance pathway is clear:
AS 1530.2: Flammability Index Test
Our construction-grade, fire-retardant polystyrene core is tested and proven to meet Australian requirements for flammability.
AS/NZS 4859.1:2018 – insulation materials standard.
Governs thermal material properties, labelling and compliance.
AS/NZS 4859.2:2018 – insulation thermal performance.
ThermaDoor Premium has the best verified R-values for garage door insulation in Australia – calculated under this standard for accuracy.
Together, these standards ensure ThermaDoor Premium is safe, compliant, and reliable for use in residential garages.
Some companies promote the products they are selling as garage door insulation as “fire rated”. This usually comes from testing done for wall or roof applications – not for garage doors. In a garage door, that rating is irrelevant, because the steel door itself provides the fire resistance.
What really matters is whether the insulation is:
Fire-retardant Tested to AS 1530.2 Compliant with Australian insulation standards
With ThermaDoor Premium, you get a product that’s purpose-made, fire-retardant, and proven compliant – giving you confidence your home is protected.
Some insulation suppliers promote ISO 9705 results when marketing their products. ISO 9705 is a “room corner test” used internationally to assess how wall or ceiling linings contribute to fire growth in a full-scale room fire. It measures flame spread, smoke and heat release – this is relevant for exposed linings like plasterboard or wall panels.
For garage door insulation, ISO 9705 is not required under the National Construction Code. That’s because the insulation is not an exposed lining – it sits behind a non-combustible steel garage door skin. The correct compliance pathway is flammability testing to AS 1530.2.
So, while ISO 9705 can be useful in other contexts, it has no bearing on garage door insulation compliance in Australia.
Insulation materials standard.
Thermal performance calculations. Ensures accurate, verifiable R-values.
Flammability index test. Applied to construction-grade EPS, confirming fire-retardant compliance.
Garage doors and large access doors. Steel garage doors are non-combustible and provide the fire resistance.
Fire resistance of building elements. Only relevant if a complete fire-rated door assembly is required.
Australia’s national building code (NCC) requires fire ratings for walls, roofs, and floors – which is why some insulation products, like PIR, carry a fire rating.
But garage doors are different: the steel door itself provides the fire resistance, not the insulation.
That’s why ThermaDoor Premium is designed the right way — using fire-retardant, construction-grade polystyrene, tested to AS 1530.2 and compliant with AS/NZS 4859.1 & 4859.2.
Safe. Compliant. Purpose-built. That’s what makes ThermaDoor Premium the smart choice for Australian garage doors.
At ThermaDoor we want you to do your own research before investing in garage door insulation and come back to us with the hard questions. To get you started, we have created a Buyers Checklist that will assist you to ask the correct questions when shopping around for garage door insulation.
No.
The building code (NCC) calls for fire ratings in walls, roofs and floors — that’s why some products, like PIR, come with a “fire rating.”
Garage doors work differently. The steel door already provides the fire protection, so the insulation doesn’t need a separate fire rating.
That’s why ThermaDoor Premium is made the right way: with fire-retardant, construction-grade polystyrene, independently tested to AS 1530.2 and proven compliant with Australian insulation standards (AS/NZS 4859.1 & 4859.2).
Fire-rated insulation (such as PIR) is tested for use in walls, roofs, or floors that must achieve a Fire Resistance Level (FRL) under the NCC. This involves testing to AS 1530.3/4.
Fire-retardant insulation (like ThermaDoor Premium’s construction-grade polystyrene core) is tested to AS 1530.2 for flammability and designed to self-extinguish, making it safe for use behind steel garage doors. In this context, fire-retardant is the correct and compliant requirement.
Yes.
ThermaDoor Premium is made with a fire-retardant, construction grade polystyrene core, tested to the Australian flammability standard (AS 1530.2) and verified for thermal performance under AS/NZS 4859.2. Together, this makes it fully compliant with Australian standards for garage door insulation.
Got more questions? Learn about Australia’s original and still the only purpose made garage door insulation in our Garage Door Insulation FAQ’s
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