Trestles Safe Work Method Statement

Maximum safe span distances for scaffold planks used on trestle platforms are specified in AS/NZS 1576.3 Scaffolding standards based on plank width and are absolute limits that must not be exceeded. For 225mm wide scaffold planks (the most common width used in Australian construction), the maximum span between trestle supports is 1.2 metres measured centre-to-centre of support points. For wider 300mm scaffold planks, maximum span increases to 1.5 metres. These span limits are based on load testing demonstrating safe capacity under standard loading conditions (225 kg/m² for light-duty platforms) and include appropriate safety factors accounting for material variability and loading uncertainties. Exceeding these maximum spans causes excessive plank deflection creating both immediate failure risk when heavy loads are positioned at mid-span and progressive structural damage from repeated loading cycles that can lead to eventual plank failure even under lighter loads. It is important to understand these are maximum limits not targets—using shorter spans provides additional safety margin and is recommended particularly for heavily loaded platforms, damaged or deteriorated planks, or work involving significant dynamic loading from worker movement or material handling. Some organisations implement policy limits shorter than standards (such as 1.0 metre for 225mm planks) to eliminate field judgment variations and provide consistent conservative approach. When measuring span distances, ensure you measure between actual support points where planks bear on trestle structures, not between trestle leg bases which may give misleading spacing measurements. If work requirements appear to demand spans exceeding safe limits, the solution is additional trestle supports creating multiple shorter spans, not rationalising that slightly excessive spans are acceptable for the specific application.

Fall protection requirements for trestle platforms are determined through fall risk assessment rather than based solely on absolute height thresholds, meaning work from platforms below 2 metres may still require fall protection depending on risk factors. Australian WHS regulations require eliminating or minimising fall risks so far as reasonably practicable, which requires consideration of multiple factors beyond platform height including the landing surface characteristics (concrete, tile, or hard flooring versus soft surfaces), work activity requirements for reaching, leaning, or working near platform edges, duration of platform occupation and cumulative fall exposure, worker experience and competency in maintaining balance on platforms, and objects or equipment below platforms that workers could strike during falls. Falls from even modest heights of 1-1.5 metres frequently cause serious injuries including wrist fractures when workers attempt to break falls, ankle injuries from awkward landing positions, head injuries from striking hard flooring, and spinal compression injuries when landing on buttocks or lower back. The 2 metre threshold often referenced represents a height above which guardrails must be installed on general scaffolding work platforms, but this does not mean work below 2 metres is automatically safe without fall protection. Your fall risk assessment may identify that edge marking, task positioning to maintain distance from platform edges, reduced platform height to minimise fall distance, or personal fall restraint systems provide appropriate risk controls for sub-2-metre trestle work even when guardrails are not mandated. Conversely, some scenarios below 2 metres present elevated risks requiring formal fall protection—for example, work requiring significant reaching or leaning, work above machinery or sharp objects, or work by inexperienced personnel. The key principle is conducting proper risk assessment considering all factors rather than applying simplistic height-based rules. Document your risk assessment findings and implemented controls demonstrating that fall risks have been systematically evaluated and appropriately managed regardless of platform height.

No, using general construction timber as substitutes for proper scaffold planks on trestle platforms is prohibited and creates serious safety risks. Scaffold planks must conform to AS/NZS 1576.3 standards, which specify timber grades, minimum dimensions, moisture content limits, defect restrictions, and load testing requirements ensuring planks have adequate strength and reliability for supporting workers and materials at height. These standards require timber to be graded for structural use with defects including knots, slope of grain, and irregularities limited to levels that do not compromise load capacity. Construction timber sold for general building use is not graded to these standards and may contain defects that significantly reduce strength including large knots, excessive slope of grain, wane (bark or missing wood at edges), splits, and shakes (cracks along growth rings). Additionally, construction timber dimensions may be nominal rather than actual—for example, 200x50mm nominal timber often measures 190x45mm actual, reducing load capacity compared to 225x50mm scaffold planks. The consequences of using inadequate platform materials include sudden plank failure causing falls from platform height, progressive deflection creating unsafe working surfaces, and splitting or cracking during use creating falling hazards. Scaffold planks are specifically manufactured, graded, and tested for their critical safety function supporting workers at height and represent modest investment compared to injury costs and liability exposure from using inappropriate substitutes. If you lack proper scaffold planks for required trestle work, the solution is obtaining correct materials through purchase or rental from scaffolding suppliers, not improvising with construction timber. Many incidents have occurred where workers rationalised that timber appearing robust was suitable for temporary platform use, only for materials to fail under loading with serious consequences. Regulatory inspectors will immediately identify use of non-compliant platform materials and issue prohibition notices stopping work, reinforcing that proper equipment is not negotiable for safety-critical applications.

Foundation stability for trestle platforms is verified through visual assessment of surface characteristics, physical testing of assembled configuration, and monitoring throughout use. Suitable foundation surfaces are firm, level, and stable—concrete slabs, structural floors, compacted ground, or paved surfaces typically meet these criteria. Unsuitable foundations include sloping floors exceeding approximately 3 degrees or 1:20 gradient, soft or compressible materials that allow trestle legs to sink under loading such as soil, loose gravel, or temporary surfaces, slippery surfaces lacking friction to prevent base sliding such as polished tiles or plastic sheeting, and uneven surfaces where trestle legs cannot achieve simultaneous firm contact. Before assembling platforms, visually inspect the intended foundation identifying any concerns including visible slope, soft spots, or unstable materials. After positioning trestle supports but before loading platforms, test stability by applying moderate sideways force to individual trestles—push with approximately 50kg force at trestle height—verifying supports do not slide, sink, or show movement. Repeat stability testing after platform planks are positioned but before workers or materials are loaded, checking for settling or movement that may not have been apparent with unloaded trestles. During work activities, remain alert for developing stability problems including progressive sinking where trestle legs gradually settle into soft surfaces, sideways movement when workers move on platforms or handle materials, or rocking motions indicating uneven leg contact. If any instability is detected at any stage, stop work and address foundation problems before continuing—solutions include relocating to suitable surfaces, installing load-spreading base plates or timber pads under trestle legs, shimming to achieve level support on minor irregularities, or implementing alternative access methods if suitable foundations cannot be established. Never rationalise that marginal stability is acceptable for brief work periods or light loading—foundation failures occur suddenly when critical thresholds are exceeded and provide no warning allowing corrective action. Document foundation assessment in pre-work inspection records noting any concerns and measures implemented to address them, demonstrating systematic approach to this critical safety element.

If you observe any cracking, splitting, or unusual behaviour of scaffold planks during trestle platform use, you must immediately cease work, evacuate the platform, and investigate the condition before resuming operations. Signs requiring immediate action include visible cracks appearing or extending in planks particularly running across plank width or through thickness, splitting sounds indicating wood fibres failing under stress, excessive deflection where planks sag noticeably under loading more than expected from similar previous use, or unusual movements such as planks shifting on supports or bouncing excessively when walked on. First, ensure all workers exit the platform moving carefully to avoid concentrating weight on potentially compromised planks—distribute yourselves across platform length during evacuation rather than congregating at one location. Do not remove materials from platform until workers are safely off as material removal may shift loading and trigger complete plank failure. Once platform is evacuated, inspect planks carefully without loading them, looking for crack origin and extent, splits extending from ends or edges, and overall plank condition including other defects that may have contributed to failure. If cracks or splits are visible, remove affected planks from service immediately—tag them as defective, mark clearly that they must not be used, and physically separate them from serviceable planks to prevent inadvertent reuse. Even minor cracks indicate the plank has been overstressed or has internal defects reducing capacity, and will likely fail completely if returned to service. Replace defective planks with serviceable ones conforming to AS/NZS 1576.3 standards before reassembling platform. Investigate why plank failure occurred—was platform span excessive, was loading beyond safe capacity, was the defective plank marginal condition that should have been detected during pre-use inspection? Address underlying causes to prevent recurrence. Document the incident including plank condition, work being conducted when failure was noticed, platform configuration, and corrective actions implemented. Report findings to supervisors and safety management even if no injuries occurred, as near-miss events provide valuable learning preventing future incidents. The key principle is that any evidence of plank distress requires immediate conservative response evacuating platforms and investigating rather than hoping marginal conditions will hold for work completion.

Whether trestle platforms can be left assembled between work periods depends on several safety and security considerations that must be systematically evaluated rather than assuming platforms can remain in place until work is complete. Platforms left assembled overnight or during extended breaks create fall access risks for unauthorised personnel particularly in residential or public buildings where children or building occupants could access and fall from platforms, security risks where platforms could be used by intruders to access upper levels or building systems, liability exposure if third parties are injured using unattended platforms, and weather exposure for outdoor installations where wind or rain could destabilise platforms or damage components. If platforms will remain assembled, implement several essential controls: remove all materials, tools, and equipment from platforms eliminating stored items that add unnecessary weight, present falling object hazards, and may attract unauthorised access; establish physical barriers preventing access using fencing, warning tape, or barricades surrounding platform bases with signage warning of fall hazards; remove access components such as step ladders or portable stairs that provide climbing access to platforms, requiring deliberate effort to board rather than casual access; secure platforms against movement from wind loading or inadvertent contact using tie-backs to building structures or additional bracing; conduct daily pre-use inspection before resuming work verifying no damage, displacement, or deterioration occurred during non-use period; and document decisions to leave platforms assembled including assessment of access control measures and authorisation by site supervision. In many situations, the safest approach is dismantling trestle platforms at completion of each work period and reassembling when work resumes—while this requires additional labour, it eliminates all unattended platform risks and forces daily pre-use inspection and stability verification before each use period. Some contracts or site rules prohibit leaving trestle platforms assembled during non-work periods requiring mandatory dismantling regardless of work continuity. Even for platforms remaining assembled, never exceed several days without inspection and verification—extended periods create opportunity for deterioration, tampering, or environmental damage requiring assessment before platforms are safe for continued use. Document all decisions about leaving platforms assembled demonstrating systematic risk assessment and control implementation rather than convenience-based default to leaving work setups in place.