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Metal strap bracing

Metal strap bracing is a tensioned wall-brace type under AS 1684.2 (about 1.5 kN/m). Installed in opposed pairs at 30 to 60 degrees, and it must be tensioned to work.

By Chalkline. Last updated 25 May 2026. Verified 25 May 2026.

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Metal strap bracing is a wall-bracing method that uses thin tensioned metal straps fixed diagonally across the frame to resist racking. It is one of the bracing types listed in AS 1684.2 Table 8.18, and it is the lighter-duty option alongside sheet bracing. For how bracing demand is calculated and balanced, see wall bracing.

How it works

A metal strap only carries load in tension, not compression. A strap pulled tight across a racking wall resists movement in one direction, but goes slack when the wall tries to rack the other way. So straps are installed in opposed pairs, one running each diagonal, so that whichever way the wall is pushed, one strap is in tension.

The two defining rules:

  • It must be tensioned at installation. A slack strap does nothing until the frame has already racked and pulled it taut, by which point the wall has moved. Tensioning each end at install is what makes the brace work; an untensioned strap is effectively no brace.
  • The angle must stay between 30 and 60 degrees. Outside that range the strap is non-compliant and its rated capacity does not apply.

Capacity

Under AS 1684.2 Table 8.18, a tensioned metal strap brace provides roughly 1.5 kN/m of bracing capacity, with combined strap-and-stud systems rated higher (around 3.0 kN/m). That is modest compared with sheet bracing, so strap bracing suits lower-demand wall lines; high-demand lines (higher wind classes, long open walls) usually need sheet bracing or a proprietary system.

Straps are fixed to the top plate, bottom plate, and studs with the fastener type and spacing set in Table 8.18 or the manufacturer’s data. Proprietary tension braces (such as the Pryda Speedbrace) are common variants assessed in the maker’s design guide.

For a builder

  • Tension every strap. This is the number-one strap-bracing defect: straps installed loose. They must be tight at fix-off.
  • Pairs and angle. Opposed pairs, 30 to 60 degrees; a single strap or a too-flat strap will not hold the rated capacity.
  • Match capacity to demand. 1.5 kN/m is light; confirm the strap count and type meet the bracing plan, or step up to sheet bracing.

Also known as: strap brace, tension brace, diagonal strap brace.

See also

Last updated: 2026-05-25. Verified: 2026-05-25. Quarterly review for currency.

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