Hebel PowerWall can be subjected to a fire loading as the result of either an external fire source, or an internal fire source. When the wall requires a fire resistance level (FRL) rating, CSR Hebel provides the following guidance.
External Fire Source.
For an external fire source, the excellent fire resistance qualities of the Hebel PowerPanel cladding protects the structural support framing, and provides a high fire resistance level for Hebel PowerWall.
The FRL rating of the wall can be affected by the penetrations and the method adopted to protect these penetrations. A fire collar with a –/120/120 FRL rating will govern the FRL of the wall, even if the wall configuration has a FRL rating of –/180/180. Where required, the performance of the external coating when subjected to a fire loading shall meet the appropriate performance requirements outlined in the BCA. Joints & gaps need to be appropriately fire rated. Eg. vertical control joint will need fire rated sealant & horizontal joints must be blocked with compressible fire rated material.
Fire Certificates & Reports.
Copies of the test reports and/or opinions can be obtained by contacting CSR™ Hebel™. A certificate of test FSV0356 is provided in Appendix D of this guide. Hebel™ PowerWall™ achieves a FRL of 240/180/180.
Internal Fire Source
For an internal fire source the studs must be protected by the internal wall linings. Refer to CSR™ Gyprock Red Book for specifications.
External Walls in Fire – BCA Provisions
Where necessary, the designer and builder should ensure the structural support framing, its connections as well as the Hebel PowerPanel installation are satisfactory when subjected to fire conditions. The BCA Vol 2 (Part 3.7.1) outlines provisions for external walls for fire resistance in a residential building where the external wall is less than 900mm from an allotment boundary or 1.8m from another building on the same allotment. If this occurs an FRL of not less than 60/60/60 is required from the outside.
7.2 Fire Performance of Hebel PowerWall
Hebel PowerWall was tested at the CSIRO, North Ryde and a Fire Resistance Level (FRL) of 240/180/180 was achieved (refer to Appendix D). Note, the fire source was on the PowerPanel side. This excellent result enables Hebel PowerWall to be used in the following applications:
- Walls on zero line allotment blocks.
- Multi-storey residential dwellings – external walls.
- Commercial developments.
- Infill PowerPanels.
In the above applications, each PowerPanel should be screwed as specified in this guide, except a minimum of three screws should be installed through the middle top hat into each PowerPanel™ (refer to the fire test certificate in Appendix D).
Fig. 7.1 Bushfire Area
7.3 Bushfire Areas
BCA 2006 Vol. 2 Part 3.7.4 describes the provisions applicable to construction in bushfire prone areas. The reference code is AS3959. Hebel PowerPanel™ is non-combustible and suitable for all bushfire exposure levels (refer to Appendix A.6).
7.4 Design Considerations
Fire Stop Penetrations
Penetrations through Hebel PowerPanel to accommodate pipework, electrical cabling or ductwork will have to be protected (fire stop), to prevent the spread of fire through the penetration. The penetration can be protected with proprietary products, such as:
- Fire rated sealants.
- Fire collars and intumescent wraps.
- Fire rated mortars.
- Fire rated pillows.
- Fire rated switch boxes
CSR Hebel recommends contacting the manufacturer to obtain the appropriate product/solution and installation method for the application and wall configuration.