How to Back Block Plasterboard Joints

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Studco B005 offers a more cost-effective joint with greater strength.

Studco® B005 Butt Joint Batten has been developed with the plasterboard industry and provides a consistent recess shape for the finishing of joints when installed as per the plasterboard manufacturer’s recommendation.

Back-blocking is a joint reinforcing system where Studco B005 back blocking battens are screwed behind the sheets, at certain joints. Back-blocking is an important safety measure, to reinforce certain joints which often undergo additional stresses and are therefore more vulnerable to cracking.

These stresses can be caused by many reasons, including subsequent building movement or by abnormal loadings such as heavy traffic beside the wall, or trades people moving about in the ceiling spaces.

The consequential cracking of the finished jointing often requires a call-out for warranty repair, which is an avoidable and unwanted additional cost to the installer/builder.
Back blocking is recommended by all plasterboard manufacturers. The Australian and New Zealand Standard 2589.1 has a minimum requirement that B005’s should be used for all butt joints and in any area with 3 or more recessed joints.

The decision as to back blocking of all joints not just the minimum requirement in the Standard is best made by the builder after consideration of factors such as:

• Moisture content of timber.
• Maintenance history for similar installations.
• Type of roof framing and timber used.
• Severity of temperature and humidity conditions to which the installation will be subjected.

Butt joints which are to be back-blocked must be formed midway between framing members.

Where mid-span butt or end joints are not required but are used to minimise plasterboard wastage, these joints must also be back-blocked. All mid-span joints must be positioned within 50mm of the mid-span point between the framing members.

For architectural specifications or installation advice, please contact Studco Building Systems for fast, friendly service at techadvice@studcosystems.com.au or call 1800 STUDCO

Studco Back Blocking Batten