Best practice scaffold usage

Soleboards and baseplates

Soleboards and baseplates can be used to evenly distribute the load from the scaffold to the supporting surface. Both soleboards and baseplates may be required for use on less stable surfaces, such as soil, gravel, fill or other product which creates a system of beams and flat slabs

Each scaffold should be designed to carry the required number of working platforms and to support its live loads. Scaffold planks on working platforms should:

• have a slip-resistant surface;
• not be cracked or split;
• be of uniform thickness;
• be captive (that is, cannot be kicked off ) and not be capable of uplift or displacement during normal use;
• be positioned so that no single gap;
• between planks exceeds 10 millimetre; and,
• not be lapped on straight runs of modular and tube and coupler scaffolding but may be lapped on hanging bracket scaffolds where butting of planks at a pair of brackets cannot be achieved.

Lapped scaffold planks may sometimes be used to cover gaps around corners of scaffold bays. These planks generally may not need to be secured, provided the following are met:

• timber is lapped over metal planks;
• planks are 1.2 metres long or greater;
• plank overlap, past the edge of the plank underneath, is 300 millimetres or greater; and,
• standards prevent planks from moving sideways on the scaffold.

If using plywood sheets to cover gaps between scaffold bays the plywood sheets should be:

• a minimum of 17 millimetres thick;
• only used to cover gaps less than 500 millimetres wide (unless approved by an engineer); and,
• secured.

Metal planks lapped on other metal planks should be secured using fixings such as a double tie wire or strapping. Tie wire or any other system that is not structurally rated should not be used to secure planks on hop-up brackets.

• Planks should be secured.
• All hop-up brackets should be provided with tie bars to stop brackets from spreading apart, causing planks to dislodge, unless otherwise specified by the scaffold designer.
• The overhang of planks which are supported by putlogs should be greater than 150 millimetres but less than 250 millimetres – otherwise uplift might occur.
• Avoid nailing or screwing laminated planks into position, unless otherwise specified by the manufacturer. Moisture penetrating the planks can cause damage and may not be easily detected.

Scaffold working platforms are generally rated as light, medium or heavy duty:

• Light Duty – Up to 225 kilograms per bay. Examples include painting, electrical work, many carpentry tasks and other light tasks. Platforms should be at least two planks wide (approximately 450 millimetres).
• Medium Duty – Up to 450 kilograms per bay. This is suitable for general trades work. Platforms should be at least four planks wide (approximately 900 millimetres).
• Heavy Duty – Up to 675 kilograms per bay. This is what is needed for bricklaying, concreting, demolition work and most other work tasks involving heavy loads or heavy impact forces. Platforms should be at least five planks wide (approximately 1000 millimetres).

Control measures to eliminate or minimise the risk of a falling object can include catch platforms, perimeter screening and exclusions zones.

Fall arrest platforms

A fall arresting platform can be used as a risk control measure to arrest a person’s fall during work at height.

If the slope of the surface where work is being done is:

• not over 26º – then install the platform no more than 1 metre lower than the surface; or,
• over 26º – then install the platform no more than 300 millimetres lower than the surface.

Access and egress

Workers must be provided with safe access to and egress from scaffold during the erection, use and dismantling of scaffold. Common means of access and egress include:

• temporary stairs or portable ladder access systems installed at the start of erection, progressed with the scaffold, and used by the scaffolder whenever possible;
• permanently installed platforms or ramps;
• personnel hoists (non-mechanical forms of egress, such as a ladder or stair tower should be provided in case of emergency); and,
• using the existing floor level of a building, provided such access is safe. Scaffolders should not climb standards externally.

Stairs should be secured to the scaffold bay. If not secured, the supplier should provide documentation illustrating the maximum amount of clearance allowed between the transom and the top and bottom of the stair module. Ensure the gap between the end of a stair module and a transom is as small as practicable. Large gaps can lead to stairs dislodging and falling when a load is placed onto it.

Ladders

Extension or single ladders should only be used as a means of access to or egress from a work area, not as a working platform. The following are additional safe work practices which should be followed when working on ladders:

• Ladders may be used where access to the working platform is needed by only a few persons, and where tools and equipment can be delivered separately to the working platform (for example, by materials hoist, crane or a rope and gin wheel).
• Ladders should be within a separate ladder access bay of the scaffold, wherever space permits.
• If the access bay is part of the working platform, a trap door is to be provided. Strict controls should be implemented to ensure the trap door remains closed while working from the platform.
• Ladders should be set up on a firm, level surface and not used on scaffold bays to gain extra height.

Fall-arrest systems

Fall-arrest systems can be used as a risk control measure to arrest a person’s fall when working on a scaffold. However, fall-arrest systems are not usually appropriate for erecting a scaffold because:

• workers are likely to hit a component of the scaffold before the fall is arrested;
• obtaining suitable anchorage points that can support a load of 15kN may be difficult;
• continuously hooking on and off the scaffold may be inconvenient; and,
• fall arrest lines may become trip hazards.

Fall-arrest systems should only be used during the following scaffold activities:

• erecting or dismantling ‘drop’ or ‘hung’ scaffold where the scaffold is constructed from top to bottom, this allows for a clear fall zone, in the event of a fall;
• the fixing and removal of trolley tracks on suspension rigs;
• erecting or dismantling cantilevered needles and decking between the needles. Fall arrest systems could also be used during the erection of the first lift of scaffold where workers are standing on the deck between the needles;
• the erection and dismantling of cantilevered scaffolds prior to or when removing the initial platform; and,
• the attachment and removal of spurs projecting from the supporting structure.

Electricity

Any construction work that is carried out on or near energised electrical installations or services is high risk construction work and a SWMS must be prepared before this work commences. Contact with overhead electric lines has the potential to cause serious life threatening injuries or death.

Electrical power sources, whether overhead or underground can be a major hazard. In addition to direct electric shock and possible electrocution, contact with overhead electric lines can lead to a variety of hazards including arcing, explosion or fire causing burns, unpredictable cable whiplash and the electrifying of other objects (for example, signs, poles, trees or branches). Specific control measures must be implemented when work is done in the vicinity of electric lines. The local electricity supply authority should be consulted and appropriate risk controls implemented.

Mobile scaffold

A mobile scaffold is a tower scaffold that is mounted on castors. Manufacturers and suppliers must provide information regarding the safe use and erection of mobile scaffolds. If a scaffold is to be altered, contact the manufacturer or supplier for additional guidance. All modular mobile scaffolds are to be erected in accordance with manufacturer’s specifications.

The following control measures should be implemented for mobile scaffolds:

• The height of a mobile scaffold, from the bottom of the scaffold to the working surface, should be no greater the multiple of the minimum base dimension as specified in the manufacturer, supplier or designer information.
• Where adjustable castors are used, the slope of the surface should not exceed 5 degrees.
• Use a secure internal ladder with a protected opening (for example, a hinged trap door) for access and egress to and from the scaffold.
• Select the appropriate size and capacity castors to support the total mass of the dead and live loads of the scaffold.
• Use castors that have the working load limit clearly marked.
• Castors fitted to standards should be locked before erection continues.
• Castors with adjustable legs should be used and adjusted to keep the platform level when the supporting structure is at different heights.
• Incorporate plan bracing at the base of mobile scaffolds to provide greater stability.
• Before moving mobile scaffolds check that:
• there are no power lines or other overhead obstructions;
• the ground is firm and level;
• no person is on the scaffold;
• no equipment and material can be dislodged from the platform;
• the supporting surface is free of obstructions (a small obstruction may cause a mobile scaffold to overturn);
• electrical equipment and leads cannot be tangled.
• Brakes on castors are to be locked at all times unless moving the scaffold.
• Never move the scaffold in windy conditions.
• Push or pull the mobile scaffold from the base – never use powered vehicles to move the scaffold.
• If lifting a mobile scaffold by crane, sling the scaffold at its lowest point to prevent dislodgment of scaffolding components. However, a crane should not be used to lift aluminium mobile scaffolds because the scaffolding components may fail.
• Ensure guardrails, midrails and toeboards are installed on all working platforms.

Inspection and maintenance

Procedures must be developed for the inspection and maintenance of the scaffold and scaffolding components to ensure that the scaffold is safe to use and remains in a safe condition. The inspection of scaffolds and scaffolding components at a workplace is particularly important when the scaffold is in place for a prolonged period of time.

The person responsible for the erection of the scaffold from which a person or object could fall more than four metres must provide the principal contractor or the person conducting a business or undertaking with a handover certificate which should be kept at the workplace until the scaffold has been dismantled.

Frequency of inspection

The person with management or control of a scaffold at a workplace must ensure that the scaffold and its supporting structure are inspected by a competent person:

• before use of the scaffold is resumed after an incident occurs that may reasonably be expected to affect the stability of the scaffold (for example, strong winds or storms);
• before use of the scaffold is resumed after repairs; and,
• at least every 30 days.

The frequency of inspections may vary depending on weather and workplace conditions, the type and size of the scaffold and the risks associated with scaffold collapse.

The supplier of the scaffold should also be consulted on the appropriate intervals for inspection when the scaffold is first installed.

Inspection records should be kept on site and include the location, comments, date and time of inspections, relevant design or specification reference and the person who conducted the inspection. Further information on scaffold inspection requirements refer to AS/NZS 4576 Guidelines for scaffolding.

Working platforms, except suspended scaffolds should have duty classifications and dimensions complying with the manufacturers’ information on loadings.

Guardrails or personal fall arrest systems for fall prevention/protection are required for workers on platforms 2 metres or above.

Scaffold planks on working platforms should not be lapped on straight runs of modular and tube and coupler scaffolding.

Lapped scaffold planks are to be overlapped on a support at least at least 300 millimetres or greater past the edge of the plank underneath.

Legs, posts, frames, poles, and uprights must be on base plates and mud sills, or a firm foundation and, be plum b and braced.

Scaffold user training must include:

• The hazards of type of scaffold being used.
• Maximum intended load and capacity.
• Recognizing and reporting defects.
• Fall hazards.
• Electrical hazards including overhead lines.
• Falling object hazards.
• Other hazards that may be encountered.

General provisions for all scaffolds:

• Scaffolding should be assembled by a competent person up to 4 metres and by a licenced person for high risk scaffolding above 4 metres.
• Provide safe ladder access— Scaffolders should not climb standards externally.
• Use scaffold-grade components for platforms.
• Install guardrails, mid-rails and toeboards on all scaffolds that are 2 metres above the ground.
• Train all personnel in safe use (training and inspection by a competent person).
• The dead, live and environmental loads need to be calculated during the design stage to ensure the supporting structure and the lower standards are capable of supporting the intended loads.

A scaffold is a temporary structure specifically erected to support access or working platforms. Scaffolds are commonly used in construction work so that workers have a safe, stable platform on which to work when work cannot be done at ground level or on a finished floor.

Scaffolds, once properly erected, are a control measure to prevent the risk of persons and objects falling when working at height.

Training specific to the scaffold and/or scaffolding work and to the workplace should also be provided to workers. Workers in a supervisory role (for example, leading hand or foreman) should be experienced and trained in scaffolds and scaffolding work.

High risk work licences

A person performing scaffolding work must hold the relevant scaffolding licence class if a person or thing may fall more than 4 metres from the scaffold.

Competent persons where licence is not required

A person is not required to hold a scaffolding licence if a person or thing may fall 4 metres or less from the scaffold. However, any person performing scaffolding work should be competent and must be provided with relevant information, instruction, training and supervision in the safe erection, dismantling, maintenance and alteration of the scaffold.

Each scaffold should be designed to carry the required number of working platforms and to support its live loads. Scaffold planks on working platforms should:

• have a slip-resistant surface;
• not be cracked or split;
• be of uniform thickness;
• be captive (that is, cannot be kicked off) and not be capable of uplift or displacement during normal use;
• be positioned so that no single gap between planks exceeds 10 millimetres; and,
• not be lapped on straight runs of modular and tube and coupler scaffolding but may be lapped on hanging bracket scaffolds where butting of planks at a pair of brackets cannot be achieved.

Heavy and light trades have different requirements:

• Light trades such as painters & electricians may work from heavy duty scaffolds.
• Heavy trades such as bricklayers may not work from light duty scaffolds.

Common means of access and egress include:

• temporary stairs or portable ladder access systems installed at the start of erection, progressed with the scaffold, and used by the scaffolder whenever possible;
• permanently installed platforms or ramps; and,
• personnel hoists (non-mechanical forms of egress, such as a ladder or stair tower should be provided in case of emergency), and using the existing floor level of a building, provided such access is safe.

Scaffolding safety considerations

Safety requirements and other considerations for scaffolds include:

• scaffolding should conform to the AS/NZS 1576 series or their most recent equivalents;
• all scaffolding must be erected, altered and dismantled by a competent person;
• if a person could fall 4 or more metres from a scaffold, that scaffold must be erected, altered and dismantled by the holder of a certificate of competency for the appropriate class of scaffolding;
• a person must not alter scaffolding without authority from the person with control of the construction project;
• scaffold platforms should be a minimum of 450 millimetres wide;
• modular scaffolds should be of the same type, not mixed components. Mixed components from different manufacturers have resulted in scaffold incompatibilities and failures, posing significant risks to persons using the scaffolding;
• mobile tower frame scaffolds can be used to provide safe working platforms;
• brick guards or mesh panels should be fitted to working platforms where bricks are being stacked and laid;
• the maximum load capacity of a scaffold must never be exceeded;
• a scaffold that is incomplete and left unattended should have danger tags and warning signs attached at locations to prevent use, and access points to the incomplete scaffold blocked off;
• all long term scaffolds, regardless of height, should be checked regularly for structural integrity by a competent person;
• scaffold exceeding 4 metres in height should be inspected and tagged by a competent person before use, after any alteration or repair, and at intervals of not greater than 30 days;
• additional inspections should be carried out by a competent person following an occurrence such as a severe storm or earthquake;
• safe access to and egress from the scaffold should be provided; and,
• edge protection (guardrails and toeboards) should be provided at every open edge of a scaffold working platform. Meshing should be installed over access and egress points.

The safety requirements for guardrails include:

• every open edge of a stair, landing, platform or shaft should be protected to prevent a person falling;
• the guardrail system should be constructed to withstand a force of 0.55 kN (approximately equivalent to 55 kilograms) applied at any point. Where edge protection is used on roofs with pitches exceeding;
• 15 degrees from the horizontal, the edge protection should be able to withstand the added impact forces;
• top-rails should be between 900 millimetres and 1100 millimetre above the working surface;
• midrails and toeboards should be provided. However, wire mesh infill panels incorporating a toeboard may be used instead of the mid-rail;
• a bottom rail above the toeboard should be provided for more severe roof slopes. Both a mid-rail and infill mesh panel will assist in preventing persons and objects from falling through;
• guardrails should comply with AS 1657 and/or AS/NZS 4576 or their most recent equivalent;
• if access points are required for equipment (for example, a hoist), they should be protected with gates, safety chains or other means to prevent a person from falling through; and,
• where guardrail systems are intended to be used in conjunction with steel structures or tilt-up construction, designers and builders should plan for the guardrails and fixings to be attached to the panels prior to the structures being raised from the ground.

The following is a list of some of the more common issues that should be taken into consideration when identifying fall hazards in the workplace.

Catch platform

A catch platform is a temporary platform located below a work area designed to catch a falling person. The platform should be of robust construction and designed to withstand the maximum potential impact load. Scaffolding components may be used to construct fixed and mobile catch platforms. Catch platforms should:

• incorporate a fully planked-out deck;
• be positioned so the deck extends at least 2 metres beyond all unprotected edges of the work area, except where extended guardrailing is fitted to the catch platform;
• be positioned as close as possible to the underside of the work area. It is recommended that the distance a person could fall before landing on the catch platform should be no more than 1 metre; and,
• always be used with an adequate form of edge protection.

Trestle scaffolds

Heavy duty trestle scaffolds and split-head trestle scaffolds can provide simple and inexpensive catch platforms. The latter are particularly effective in openings and stairwells.

Trestle scaffolds may be used at heights greater than 2 metres only when guardrailing and toeboards are incorporated to prevent people and material falling off the open side or end of the working platform. The system (including planks) should be assembled according to the manufacturer’s specifications. Trestle scaffolds without guardrailing are only suitable for tasks requiring a work platform of less than 2 metres. Some trestle ladder scaffolds include outriggers to increase stability. Trestle ladder scaffolds are only suited to light duty tasks such as painting and rendering.

When adjusting the height of a trestle scaffold, make sure that only the purpose-designed pins are used. Do not use nails or pieces of reinforcing bar.

Work should only be performed between the trestles. The working platform of a trestle scaffold should be a minimum of two planks or 450 mm wide. The maximum spacing of trestles should not exceed the maximum recommended span of the scaffold planks. Since 1993, random length scaffold planks manufactured in accordance with AS 1577 or most recent equivalent have this information marked on them. Where this information is not known, reference should be made to the table below.

Permit systems

Permit systems ensure that only competent persons trained in the use of appropriate control measures work in an area where there is a fall hazard.

Examples include:

• tagging all access points to a scaffold to prevent unauthorised access during erection and dismantling, with ‘only licensed scaffolders permitted on an incomplete scaffold’; and,
• requiring permits for access to areas where travel restraint systems or fall-arrest systems are to be used.