Fire resistance of external light gauge steel framed walls with brick veneer cladding

Abstract

This paper presents the details of an experimental study to evaluate the fire resistance of external light-gauge steel-framed (LSF) walls with brick veneer cladding. Brick veneer is one of the most opted external cladding in Australian low to mid-rise construction for their aesthetic appeal with load bearing light-gauge steel framing or timber framing as the structural backing. However, no experimental data is available on the fire resistance of brick veneer walls with LSF backing. This experimental study included five small-scale non-load bearing fire tests of LSF walls with brick veneer cladding exposed to the standard fire. Two test walls with brick veneer constructed using normal and high temperature mortars were tested with fire from the external side (brick veneer exposed to fire), and the third wall constructed using normal mortar was tested with fire from the internal side (plasterboard exposed to fire). The first two test walls were also exposed to a second fire exposure. This study also included detailed elevated temperature thermal property tests of brick and the two types of mortar used in the fire tests. Brick veneer cladding provided very good protection to the thin-walled steel studs. No failure was observed in all the five fire tests giving fire resistance level of more than 240 min. Structural failure times of load bearing walls were also estimated to be more than 240 min for fire on the external side under load ratios of up to 0.4 while it was 30 min for fire on the internal side.