Galvanised Structural Bracing Strap: Sizes, Capacities and Installation

Key things to remember

The essentials from this document in plain words. Check the full document before you rely on a figure.

• ✓Punched G300 steel strap, galvanised Z275 (minimum 275g per square metre, a minimum of 20µm per side), for wall bracing to AS 1684 Section 8.3.6 in single and two-storey timber framing.
• ✓Sizes: 30mm wide in 0.8mm (20, 30 and 50m rolls), 1.0mm (20, 30 and 50m) and 1.2mm (30m); 32 x 1.2mm (30m); and an unpunched 30 x 0.8mm (30m).
• ✓Strap loads, with no capacity reduction factors applied: 30 x 0.8mm yield 4.9kN, tensile 5.6kN; 30 x 1.0mm 6.2kN and 7.0kN; 32 x 1.2mm 8.1kN and 9.2kN.
• ✓Bracing capacity for walls up to 2.7m high and bracing panels 1,800 to 2,700mm long: Type A (30 x 0.8mm) 1.5kN/m; Type B (30 x 1.0mm, 30 x 1.2mm or 32 x 1.2mm, with stud straps) 3.0kN/m. For walls 3.0 to 4.2m high apply the AS 1684 Table 8.19 multiplier, 0.90 down to 0.64.
• ✓Install as an X brace: nail one end, stretch the strap tight over the panel, nail the other end, then fit one tensioner in each leg to take out slack and nail the strap to every stud and nogging. Tension each leg progressively and do not over-tension: it reduces the strap's capacity.
• ✓Nails are 30 x 2.8mm mechanical galvanised connector plain shank nails: one per stud for both types, three at each plate for Type A and four for Type B.
• ✓Tensioners: wing (GSTMGFW30) and hex (GSTMGFH30), 2.5mm galvanised G300 plate, to suit the strap's 6.5mm tensioner holes. Nail holes are 3mm, for 2.8mm or 3.15mm nails.

Who it helps: Builders, carpenters and frame makers bracing timber framed walls, and staff checking strap sizes.