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Group 1 Insulated Soffit Lining

IBOARD G1 insulated soffit lining comprises of a Group 1 rated 6mm fibre cement facer bonded to a concealed rigid insulation board composed of a closed-cell thermoset polyisocyanurate foam. Tested in accordance with relevant AS/NZ standards, IBOARD G1 is compliant for use in all soffit applications in accordance with NCC 2022. Providing higher R-values from less thickness, IBOARD G1 allows increased clearance height within carparks while still meeting thermal requirements making it the safest and most practical option for all concrete soffit and under-slab applications.

Group 1 Fire Rating*

IBOARD G1 insulated soffit lining has a non-combustible fibre cement facer which achieves a Group 1 fire rating in accordance with AS 5637 for superior safety and compliance in all under slab soffit applications.

Unlimited Colours

IBOARD G1 insulated soffit lining has an attractive light grey fibre cement finish which can be left untreated, painted insitu, or supplied prefinished in unlimited custom colours to your selection.

Superior Ageing Performance

Due to it's outstanding resistance to moisture and excellent compressive strength, IBOARD G1 soffit insulation offers much better thermal ageing performance than other products.

100% Non-corrosive

Unlike some other insulation products, IBOARD G1 core material is 100% non-corrosive and will not cause corrosion issues if it comes in contact with structural steel or fixings.

Zero Formaldehyde

IBOARD G1 soffit insulation contians zero traces of formaldehyde and it is fibre-free making it non-irritant to the skin, non-allergenic and safer compared to other products.

Australian Fire Testing*

IBOARD G1 insulated soffit lining has NATA accredited testing to relevant Australian fire standards and it's Group 1 fire rating means it is compliant with NCC 2022 for all lining applications.

Environmentally Friendly

IBOARD G1 soffit insulation is manufactured in Europe under strict quality control using only CFC/HCFC free blowing agents which have Zero Ozone Depletion Potential (ODP).

Micro Cell Technology

IBOARD G1 has a much finer cell structure with extremely low water absorbtion compared to other products (<0.6%) so it's R-value is retained long-term and it is rot and mould proof.

*Group 1 fire rating applies to the exposed fibre cement facing in accordance with AS 5637 and NCC 2022 requirements.

*Does your project require Non-combustible materials?

If your project is required to be type A or B construction then all cladding, framing & insulation is required to be non-combustible. All the below cladding products are Deemed-to-Satisfy (DtS) non-combustible in accordance with NCC 2022, Clause C2D10 (Previously NCC 2019, Clause C1.9) and can be used anywhere a non-combustible material is required;

Aluminium Core
Solid Aluminium
Vitreous Enamel
Aluminium Cladding
Aluminium Battens
Through-colour FC
Prefinished FC
Natural-finish Panel
Wood-look Cladding
Wood-look Battens
Facade System
AS 1530.1 Insulation
Steel Top-hats
AS 1530.1 Sarking
Class 4 Membrane



Product Range

Group 1 Insulation





Lead Time


IBG362412 R1.38

IBOARD 36mm G1 Insulation, 2400 x 1200mm

1-2 Weeks

50 Boards 

IBG462412 R1.84 IBOARD 46mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards 
IBG562412 R2.29 IBOARD 56mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards 
IBG662412 R2.75 IBOARD 66mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards 
IBG762412 R3.20 IBOARD 76mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards
IBG862412 R3.66 IBOARD 86mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards
IBG962412 R4.11 IBOARD 96mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards
IBG1062412 R4.57 IBOARD 106mm G1 Insulation, 2400 x 1200mm 1-2 Weeks 50 Boards


Technical Data

Test Item


Thermal Conductivity (Insulation) ASTM C518 0.022 W/mK*
Thermal Conductivity (Fibre Cement) ASTM C518 0.23 W/mK*
Group Rating AS 5637 Group 1**
Average Specific Extinction Area m2/kg <250**
Smoke Growth Rate (SMOGRA) m2/s2x1000 <100**
Spread of Flame Index AS 1530.3 0***
Smoke Developed Index AS 1530.3 2***
Tensile Strength Perpendicular to Faces EN 1607 80 kPa
Compressive Strength EN 826 >110 kPa
Compressive Strength at 10% Deformation EN 826 >150 kPa


*Material R-values are calculated based on the insulation thickness at 0.022 W/mK in addition to the 6mm fibre cement at 0.23W/mK. **The AS 5637 testing and Group 1 rating applies to the exposed fibre cement facer, being the wall or ceiling lining, in accordance with NCC 2022 requirements. ***The AS 1530.3 testing applies to the PIR insulation board, being a concealed insulation material, in accordance with NCC 2022 requirements.




Customer Support

For same day design assistance and technical support please contact our sales team directly on the below contact details. All our sales and technical staff are locally based so we can provide the best possible service and support for your project. You can also request a technical data sheet or project quotation using the below email links;

Frank Kutra
Product Manager
1300 945 123
0477 966 027
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  • Overview
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