A series of full scale fire tests of light gauge steel frame (LSF) walls was conducted first to evaluate the fire resistance rating (FRR) of load bearing LSF wall assemblies (Gunalan et al., 2013). One wall specimen was tested to failure under an axial compression load at room temperature while ten wall specimens subjected to a constant axial compression load were exposed to standard fire conditions on one side to evaluate their fire performance (Table 1). Conventional Australian LSF wall panels lined with single (1 × 1) or double (2 × 2) layers of plasterboard with or without cavity insulation (CI) were considered. A new LSF wall system based on a composite panel (CP) was also included in which external insulation was sandwiched between the two plasterboards. Glass fibre (GF), rockwool (RW) and cellulose fibre (CF) were used as insulations in this experimental study.