WorkSafe inspectors have observed several construction sites where braces supporting concrete panels were skewed (ie not in a plane perpendicular) to the plane of the panel.
Skewed braces are weaker than those which are installed in a plane perpendicular to that of the panel, as they have less capacity than that recommended in the load charts and therefore can have an effect on the stability of the precast panel.
Brace manufacturer and supplier load charts specify braces must be:
- inclined no less than 40 and no more than 60 degrees to the horizontal
- installed in a plane perpendicular to that of the panel.
WorkSafe will not accept braces skewed more than five degrees on either side of the plane perpendicular to the plane of the panel.
- be verified by the erection design engineer
- clearly specify the limit of the skew
- be shown clearly on shop drawings.
The diagram shows the limit of skew recommended for braces when supporting precast panels.
For further information on skewed panel braces:
- National Code of Practice – Precast, Tilt-up and Concrete Elements in Building Construction
For general information on bracing:
- AS 3850 – Tilt-up concrete construction
- Victorian Industry Standard – Precast and Tilt-up Concrete for Buildings