Steel Framed Houses in Bushfire Areas with NASH

Making new homes more bushfire resistant at lower cost

Recent bushfires have again demonstrated the destructive power of ember attack. In fact, CSIRO post-disaster surveys of bushfire damage typically find that about 80% of houses in bushfires are destroyed due to ember attack. Houses constructed with non-combustible building products have an inherent benefit as these products cannot ignite when subject to ember attack. This is what the National Construction Code (NCC) requires.

As a deemed-to-satisfy solution in the NCC, the NASH Standard for Steel Framed Construction in Bushfire Areas can be used for the design of steel framed houses in designated bushfire areas in all states and territories with the exception of South Australia. The NASH Bushfire Standard was developed from full scale testing of building assemblies by CSIRO using the most powerful bushfire simulator in Australia, at the NSW Rural Fire Service training centre near Mogo, NSW.

The NASH Bushfire Standard is based on non-combustible construction; in a nutshell, basically anything that might be reached by an ember or subjected to a radiant heat flux of 40 kW/m² must be made from non-combustible material. The Standard covers dwellings with steel floor, wall and/or roof framing, steel roofing, and a range of non-combustible wall claddings. Some of the benefits of using the NASH Bushfire Standard for design of homes in bushfire areas include:

• For major building elements, one solution for homes constructed in BAL-12.5 to BAL-40 and another solution for BAL-FZ.
• Steel fascia can span up to 1200 mm.
• Steel roof cladding is not required to be sarked for BAL-12.5 to BAL-40 and normal sheeting installation can be used without additional sealing.
• Normal component clearances and workmanship may be used on the building exterior. If the building is weather- and vermin-proof, component detailing is adequate.
• The format of the Standard facilitates easy selection and checking of the solution for each building element.

For more information on designing steel framed houses in bushfire areas or to purchase the NASH Bushfire Standard in PDF or hard copy, visit the NASH website.