QBCC Technical Article: Restraints for Internal Partition Walls
A recent audit of north Queensland building sites by the QBCC revealed widespread use of non-compliant practices in relation to restraints on the tops of internal partition walls. The QBCC identified a number of builders restraining the tops of internal timber walls by firing framing nails into metal ceiling battens installed onto the underside of roof truss bottom chords (as in the picture on left).
The 'L' bracket system is compliant with AS1684 and AS4440, and is recommended by timber truss manufacturers throughout Queensland. The “L” bracket not only provides lateral restraint to the tops of partition walls, but also allows for vertical movement of the bottom chord of the roof truss via the slotted fixing channels. This is a requirement for the accepted performance of the roof truss system.
In discussions with Timber Queensland and the Cyclone Testing Station at James Cook University, the QBCC has been unable to identify any testing that has resulted in verifiable data to justify the “gun nail into metal ceiling batten” method of partition-top restraint currently being utilised by some practitioners.
The QBCC maintains its strong stance on the non-compliance of this construction method. Any potential changes to relevant Australian Standards to validate this practice would require testing to verify its performance and may take some time to then be adopted.
The QBCC will continue with its agenda to inform and educate builders, trade contractors and certifiers of the risks associated with this non-compliant construction method.
Read the full QBCC Technical Feature here.