September 14, 2022

Steel Hub completes Thermal Bridging project

The Steel Research Hub has completed its first research project. The project titled ‘Thermal Bridging by Ceiling Frame Members,’ brought together our industry partner, National Association of Steel-Framed Housing Inc (NASH), and the University of Wollongong (UOW) team from the Sustainable Building Research Centre (SBRC) to investigate heat transfer and fluid dynamics processes in residential roofs, to determine the extent of ‘thermal bridging’ caused by frame members (cold formed steel cf timber) in the ceilings of residential buildings.

NASH represents the interests of steel frame fabricators for housing and low-rise framed construction, their customers, and suppliers.  Their members include specialist steel frame fabricators, builders as well as suppliers of products and services to the industry.

The primary aim of this project was to demonstrate how typical ceiling batt insulation products interface with and fit around steel and timber frame members.  Computational fluid dynamics (CFD) simulations were used to produce high-fidelity physics-based models of heat transfer and air flow in roof spaces. Laboratory tests were undertaken to demonstrate how typical ceiling insulation batts interact with steel and timber ceiling frame members. The impact of partial and complete ‘encapsulation’ of frame members by insulation batts on the overall thermal resistance of ceilings was investigated, together with the impacts of steel frame base metal thickness, insulation batt thickness, and ceiling battens.

Findings from the project have implications for how new buildings are designed in Australia – in particular, calculations used to determine the quantity of insulation needed in ceilings and roofs of new buildings were evaluated, and improved calculation methods were proposed. The findings from the project have also been utilised by technical committees working on the 2022 update to the Australian National Construction Code, which specifies the minimum standard of new buildings in Australia.

The UOW research team included project leader and Research Fellow Alan Green, Senior Professor Paul Cooper, Associate Research Fellow Steven Beltrame and NASH’s Associate Researchers Mike Kelly and Ken Watson.

The Steel Research Hub congratulates the team on completing their project and the significant outcomes of their research. The collaboration between UOW and NASH reinforces both organisations strong commitment to supporting a resilient, value-adding, steel supply chain.

Learn more

• Steel Research Hub
• Sustainable Building Research Centre
• National Association of Steel-Framed Housing Inc (NASH)