Scaffolds

What you need to do

The law requires that employers and self-employed contractors assess the risk from work at height and go on to organise and plan the work so it is carried out safely.

Suitable precautions must be taken to prevent falls. General access scaffolds provide a means of working at height while preventing falls and should be provided whenever practicable.

Issues to consider include:

• General access scaffold requirements
• Guard rails, toe boards and other barriers
• Scaffold design
• Scaffold structures that normally require bespoke design
• Competence and supervision of scaffolding operative
• Scaffold inspection

Requirements for general access scaffolds

Scaffolds must be designed, erected, altered and dismantled only by competent people and the work should be carried out under the direction of a competent supervisor.

All scaffolding must be erected, dismantled and altered in a safe manner. This can be achieved by following National Access and Scaffolding Confederation (NASC) Safety Guidance SG4 'Preventing falls in scaffolding operations' or by following similar guidance provided by the manufacturers of system scaffolding. The key priority and objective for scaffolders is to establish collective fall protection minimising the time exposed to a fall risk and reliance upon personal fall protection equipment such as safety harnesses and lanyards. 

Strength and stability calculations for scaffolding must be carried out unless a note of the calculations, covering the structural arrangements contemplated, is available, or it is assembled in conformity with a generally recognised standard configuration.

Depending on the complexity of the scaffolding selected, an assembly, use and dismantling plan must be drawn up by a competent person. This may be in the form of a standard plan, supplemented by items relating to specific details of the scaffolding in question.

A copy of the plan, including any instructions it may contain, must be kept available for the use of anyone involved in the assembly, use, dismantling or alteration of scaffolding until it has been dismantled.

The dimensions, form and layout of scaffolding decks should be appropriate to the nature of the work to be performed and suitable for the loads to be carried and permit work and passage in safety.

Scaffolds which encroach over the highway (including pavements) require a license under Section 169 of the Highways Act 1980, which are issued by the local Highway Authority. Scaffolds should never be erected or dismantled over people or busy pavements.  If the work is likely to present a danger to the public, you should consider applying for a footpath or road closure to eliminate the risk of a member of the public being injured.  Erection and dismantling should be done inside a segregated area and during times when there are fewer members of the public in the vicinity.

Ensure the scaffold is based on a firm, level foundation. The ground or foundation must be capable of supporting the weight of the scaffold and any loads likely to be placed on it. Watch out for voids such as basements or drains, or patches of soft ground, which could collapse when loaded. Provide extra support as necessary.

Ensure it is braced and tied into a permanent structure or otherwise stabilised. Rakers only provide stability when they are braced and footed adequately; single-tube rakers alone do not usually provide this and need to be braced to prevent buckling. 

Ties must be used within their safe working load limit. Install ties as the scaffold is erected and only remove them in stages as it is struck. If a tie is removed to allow work to proceed, an equivalent tie must be provided nearby to maintain stability.

Proprietary system scaffolds must be erected and tied according to the manufacturers’ instructions.

Scaffolds must be capable of supporting loads likely to be placed on them. They are not usually designed to support heavy loads on their working platforms. If you intend to load out platforms, inform whoever is providing the scaffold – a bespoke design will likely be required.

The duty rating of your scaffold must be appropriate to the work you are doing. Scaffolds should be assumed to be ‘general purpose’ (Maximum load 2 kN/m2/200 kg/m2) unless informed otherwise by your scaffold provider. Those specifying scaffolds should be clear about the duty rating required when specifying the scaffolding required, eg an ‘inspection and ‘very light duty’ scaffold suitable for access, inspection or light cleaning will have a maximum load of 0.75 kN/m2 whereas a ‘heavy duty’ scaffold suitable for tasks involving heavy duty masonry and cladding will have a maximum load of 3.0 kN/m2.

Never sheet or attach debris netting to a scaffold without informing those involved in the design and erection of the structure that you are going to do so, as they will need to ensure the scaffold is designed for it.

Before using any scaffold, make sure that it is safe and suitable for the intended job:

• ensure platforms are fully boarded and wide enough for the work and for access (usually at least 600 mm wide)
• check that scaffold boards are properly supported and not overhanging excessively e.g. no more than four times the thickness of the board
• ensure there is safe access onto the work platforms, preferably from a staircase or ladder tower
• check that loading bays are fitted with fall protection, preferably gates, which can be safely moved in and out of position to place materials on the platform; and
• make sure the scaffold is suitable for the task before it is used and checked whenever it is substantially altered or adversely affected, eg by high winds

While a scaffold is not available for use, including during its assembly, dismantling or alteration, it should be marked with general warning signs and be suitably delineated by physical means preventing access to the danger zone.

Guard rails, toe boards and other barriers

Guard rails, toe boards and other similar barriers should be provided to prevent a person or any material or object falling from a place of work.

They must:

• be strong and rigid enough to prevent people from falling and be able to withstand other loads likely to be placed on them eg guard rails fitted with brick guards need to be capable of supporting the weight of stacks of bricks which could fall against them
• be fixed to a structure or part of a structure capable of supporting them
• include:
  • a top guard rail or other at least 950 mm above any edge from which people are liable to fall
  • a toe board sufficient to prevent a fall and any material or objects rolling or being kicked off the edge of the platform; and
  • a sufficient number of intermediate guard rails or suitable alternatives positioned so that the unprotected gap does not exceed 470 mm

Barriers other than guard rails and toe boards can be used, so long as they are at least 950 mm high, secure and provide an equivalent standard of protection against falls and materials rolling or being kicked from any edges.

Scaffold design

It is a requirement of the Work at Height Regulations 2005 that unless a scaffold is assembled to a generally recognised standard configuration, such as National Access and Scaffolding Confederation (NASC) Technical Guidance TG20 for tube and fitting scaffolds or similar guidance from manufacturers' instructions for system scaffolds, the scaffold must be designed by bespoke calculation, and by a competent person. This will ensure the scaffold will have adequate strength, rigidity and stability while it is erected, used and dismantled.

At the start of the planning process, the user must supply relevant information to the scaffold contractor to ensure an accurate and proper design process is followed. Typically this information should include:

• site location
• period of time the scaffold is required to be in place
• intended use
• height and length and any critical dimensions which may affect the scaffold
• number of boarded lifts
• maximum working loads to be imposed and maximum number of people using the scaffold at any one time
• type of access onto the scaffold eg staircase, ladder bay, external ladders
• whether there is a requirement for sheeting, netting or brickguards
• any specific requirements or provisions eg pedestrian walkway, restriction on tie locations, inclusion/provision for mechanical handling plant eg hoist)
• nature of the ground conditions or supporting structure
• information on the structure/building the scaffold will be erected against together with any relevant dimensions and drawings
• any restrictions that may affect the erection, alteration or dismantling process

Prior to installation, the scaffold contractor or scaffold designer can then provide relevant information about the scaffold. This should include:

• type of scaffold (tube and fitting or system)
• maximum bay lengths
• maximum lift heights
• platform boarding arrangement and the number of boarded lifts that can be used at any one time
• safe working load/load class
• maximum leg loads
• maximum tie spacing both horizontal and vertical and tie duty
• details of additional elements such as beamed bridges, fans, loading bays etc, which may be a standard configuration (see note 1) or specifically designed
• information in relevant drawings if appropriate
• any other information relevant to the design, installation or use of the scaffold
• reference number, date etc. to enable recording, referencing and checking

All scaffolding must be erected, dismantled and altered in a safe manner. This can be achieved by following NASC's Safety Guidance SG4 'Preventing falls in scaffolding operations' or by following similar guidance provided by the manufacturers of system scaffolding.

For scaffolds that fall outside the scope of a generally recognised standard configuration the design must be such that safe erection and dismantling techniques can also be employed throughout the duration of the works. Where this is the case, specific instructions may need to be provided with the design.

Any proposed modification or alteration that takes a scaffold outside the scope of a generally recognised standard configuration must be designed by a competent person and proven by calculation.

Scaffold structures that normally require bespoke design

Include:

• all shoring scaffolds (dead, raking, flying)
• cantilevered scaffolds ¹
• truss-out scaffolds
• façade retention
• access scaffolds with more than the 2 working lifts²
• buttressed free-standing scaffolds
• temporary roofs and temporary buildings
• support scaffolds
• complex loading bays ¹
• mobile and static towers ¹
• free standing scaffolds ¹ 
• temporary ramps and elevated roadways
• staircases and fire escapes (unless covered by manufacturers instructions)
• spectator terraces and seating stands
• bridge scaffolds ¹
• towers requiring guys or ground anchors
• offshore scaffolds
• pedestrian footbridges or walkways
• slung and suspended scaffolds
• protection fans ¹
• pavement gantries
• marine scaffolds
• boiler scaffolds
• power line crossings
• lifting gantries and towers
• steeple scaffolds
• radial/splayed scaffolds on contoured facades
• system scaffolds outside manufacturers' guidance
• sign board supports  
• sealing end structures such as temporary screens
• temporary storage on site
• masts, lighting towers and transmission towers
• advertising hoardings/banners
• rubbish chute
• any scaffold structure not mentioned above that falls outside the 'compliant scaffold' criteria in TG20 or similar guidance from manufacturers of system scaffolds.  

The above list is not exhaustive and any scaffold that is not a standard configuration or does not comply with published manufacturers' guidelines will require a specific design produced by a competent person.

Note

1. TG20:21 provides compliant scaffolds for a limited range of cantilever scaffolds, loading bays, static towers, mobile towers, use of rakers, bridges and protection fans.
2. TG20:21 provides a range of compliant scaffolds, which can be boarded at any number of lifts, but only two platforms can be used as working platforms at any one time.

Competence and supervision of scaffolding operatives

All employees must be competent  for the type of scaffolding work they are undertaking and should have received appropriate training relevant to the type and complexity of scaffolding they are working on.

Employers must provide appropriate levels of supervision taking into account the complexity of the work and the levels of training and competence of the scaffolders involved.

As a minimum requirement, every scaffold gang should contain a competent scaffolder who has received training for the type and complexity of the scaffold to be erected, altered or dismantled.

Trainee scaffolders must always work under the supervision of a trained and competent scaffolder. Operatives are classed as 'trainees' until they have completed the approved training and assessment required to be deemed competent.

Erection, alteration and dismantling of all scaffolding structures (basic or complex) should be done under the direct supervision of a competent person. For complex structures this would usually be an 'Advanced Scaffolder' or an individual who has received training in a specific type of system scaffold for the complexity of the configuration involved.

Scaffolding operatives should be up to date with the latest changes to safety guidance and good working practices within the scaffolding industry. Giving operatives job specific pre-start briefings and regular toolbox talks is a good way of keeping them informed.

Guidance on the relevant expertise of scaffolding labourers, trainee scaffolders, scaffolders and advanced scaffolders including details of which structures they are deemed competent to erect can be obtained from the Construction Industry Scaffolders Record Scheme (CISRS) website.

Scaffold inspection

It is the scaffold users/hirers responsibility to ensure that all scaffolding has been inspected as follows:

• following installation/before first use
• at an interval of no more than every 7 days thereafter
• following any circumstances liable to jeopardise the safety of the installation eg high winds.

All scaffolding inspection must be carried out by a competent person whose combination of knowledge, training and experience is appropriate for the type and complexity of the scaffold. Competence may have been assessed under the CISRS or an individual may have received training in inspecting a specific type of system scaffold from a manufacturer/supplier.

A non-scaffolder who has attended a scaffold inspection course, eg a site manager, could be deemed competent to inspect a basic scaffold structure.

The scaffold inspection report must note any defects or matters that could give rise to a risk to health and safety and any corrective actions taken, even when those actions are taken promptly, as this assists with the identification of any recurring problem.