Roof Truss Installation

Yes. Roof truss installation is classified as high-risk construction work under WHS Regulation 2017 Section 291 because it involves work at height above 2 metres with risk of fall, use of powered mobile plant (crane), and temporary support of structural elements. A SWMS must be prepared before work commences.

AS 4440:2004 is the Australian Standard for installation of nailplated timber roof trusses. It specifies mandatory requirements for temporary bracing, sequential erection procedures, fixing methods, and handling. Compliance with AS 4440 is essential to prevent truss collapse during and after erection. Key requirements include bracing the first truss back to ground, maintaining max 3m spacing for top chord ties, and not removing temporary bracing until permanent roof structure is complete.

All workers need a White Card (CPCCWHS1001) for construction site access and a Working at Heights ticket (CPCCCM2012 or RIIWHS204E) for work above 2 metres. Carpenters should hold CPC30220 Certificate III in Carpentry. If a crane is used, the operator needs the appropriate HRWL class licence, and a Dogman licence is required for slinging loads. Apprentices must work under direct supervision of a qualified carpenter.

Per AS 4440, the first truss must be braced back to ground level with diagonal braces at both ends, checked for plumb and position. Each successive truss is braced to the first using TrussSpacers or temporary ties at maximum 3m centres along the top chord and 4m along the bottom chord (3m if supporting installer weight). Gable end trusses require specific bracing per AS 4440 Appendix C. Temporary bracing must not be removed until all permanent roof structure is installed.

Minimum safe approach distances must be maintained: 3 metres for powerlines under 132kV and 6 metres for lines over 132kV (or as directed by the network operator). The electricity supply authority must be contacted before crane work near powerlines. A dedicated spotter is required, non-conductive tag lines must be used, and an exclusion zone must be established around the crane operating area.

Un-braced trusses act as sails and are extremely vulnerable to wind loading. Truss erection should cease if wind gusts exceed 30 km/h. If trusses are partially erected, all available temporary bracing must be secured immediately. Workers should descend from height until conditions improve. The competent person on site should make the call to stop work based on conditions.

Yes, but apprentices must work under the direct supervision of a qualified carpenter (CPC30220 holder) at all times. They must hold a White Card and Working at Heights ticket. Apprentices should not operate nail guns in bump-fire mode and should receive specific training on truss erection procedures and fall prevention before commencing work at height.

No worker may stand or work from an external wall top plate without a suitable fall prevention device. Options include scaffold with full edge protection, temporary guardrail systems attached to wall frames, industrial safety nets, or a fall arrest harness system with engineered anchor points rated to 15kN minimum. Travel restraint systems alone are not considered adequate fall prevention for external wall top plate work.

Trusses should be stored upright (not flat), supported at regular intervals to prevent distortion, on level ground, and secured against wind loading. They should be arranged in sequential erection order to minimise re-handling. Trusses should not be stored against un-braced wall frames as this can cause wall collapse. Protect from weather if prolonged storage is expected.

Mandatory PPE includes: safety helmet with chin strap (AS/NZS 1801), safety glasses (AS/NZS 1337.1), hearing protection Class 4-5 for nail gun and saw use (AS/NZS 1270), safety footwear with toe protection and anti-slip soles (AS/NZS 2210.3), high-visibility clothing (AS/NZS 4602.1), leather work gloves for manual handling, full body fall arrest harness (AS/NZS 1891.1) for work at height, and sun protection including SPF 50+ sunscreen.