FRR60 is often used to describe system performance requirements, but it’s not often designers and builders get to see how those numbers and letters act in the real world. Recently RAB Board by James Hardie was put to the ultimate test.
In late 2017 a large fire broke out in row of townhouses at Hobsonville Point. At the time of the fire, the property was still under construction, with HomeRAB Pre-Cladding installed on a number of external walls and James Hardie JHETGR30 — a 30 minute fire rated external wall system on the others. The system used Linea Oblique Weatherboard as the external cladding, R2.2 Insulation, and RAB Board 6mm direct fixed to framing.
The fire had been burning for at least one hour before FENZ made an entry into the building, but thanks to the fire rated wall system, the fire was well contained within the single unit and the external Linea Oblique Weatherboards on the adjacent units were not extensively damaged by the fire.
Moreover, the HomeRAB Pre-cladding used was not consumed by fire, nor did it contribute to the spread of fire, keeping damage to a minimum, and exceeding the fire safety requirements.
Further to proven fire performance, RAB Board now has a 9mm thickness which offers even more versatility. With options for SED shear wall design, as well as improved acoustic performance, RAB Board also ticks the boxes with BRANZ, offering 180 days exposure time, and is gun nailable for all applications including bracing to help improve install time.
To help specifiers navigate the complexities of fire design, James Hardie have developed a number of boundary wall systems. The Fire and Acoustic Design Manual can be found here.
Options include 30, 60, and 90-minute walls, with or without RAB Board, and with or without mineral insulation depending on specific project requirements.
Further to online resources, James Hardie has an experienced technical support team who can answer questions or assist with helping designers find the ideal system for their projects.