Listed below are the major pieces of health and safety legislation that apply to the use of edge protection systems: The Work at Height Regulations 2005 The Health and Safety at Work Etc Act 1974 (HSWA) The Management of Health and Safety at Work Regulations (MHSWR) The Lifting Operations and Lifting Equipment Regulations (LOLER) The Provision and Use of Work Equipment Regulations (PUWER) The Manual Handling Operations Regulations The Construction (Design and Management) Regulations 2007 (CDM) Construction Health and Safety at Work Regulations ( modified by WAH regulations) A guide to the safe transportation of formwork and falsework equipment Hierarchy of hazard management All edge protection activities, in common with most other construction activities, should only be undertaken when using a safe system of work. A safe system of work is a formal procedure that results from a systematic examination of a task to identify all of the hazards and assess the consequent risks. It is a means of ensuring that wherever possible hazards are eliminated or otherwise minimised by the application of appropriate control measures. It has been estimated that at least a quarter of all accidents at work involve failures in systems of work. Therefore, it is essential that the entire process of edge protection erection and dismantling, including all peripheral activities, such as storage and material handling, is covered by a comprehensive safe system of work. Hazard identification In the development of safe systems of work, the decision process should aim to identify all hazards associated with the planned activity and, if they cannot be eliminated, identify ways in which they can be effectively controlled to an acceptable level of risk. Significant hazards relating to edge protection include: • Falls from height • Lifting & lowering of loads • Manual handling • Trapping • Inadequate working space • Structural instability • Inadequate access to height • Plant and machinery 32 10. Safety requirements
Transcript
Listed below are the major pieces ofhealth and safety legislation that apply tothe use of edge protection systems:
The Work at Height Regulations 2005
The Health and Safety at Work Etc Act1974 (HSWA)
The Management of Health and Safety atWork Regulations (MHSWR)
The Lifting Operations and LiftingEquipment Regulations (LOLER)
The Provision and Use of WorkEquipment Regulations (PUWER)
The Manual Handling OperationsRegulations
The Construction (Design andManagement) Regulations 2007 (CDM)
Construction Health and Safety at WorkRegulations ( modified by WAHregulations)
A guide to the safe transportation offormwork and falsework equipment
Hierarchy of hazardmanagement
All edge protection activities, in commonwith most other construction activities,should only be undertaken when using asafe system of work. A safe system ofwork is a formal procedure that resultsfrom a systematic examination of a task toidentify all of the hazards and assess theconsequent risks. It is a means of ensuringthat wherever possible hazards areeliminated or otherwise minimised by theapplication of appropriate controlmeasures.
It has been estimated that at least aquarter of all accidents at work involvefailures in systems of work. Therefore, it isessential that the entire process of edgeprotection erection and dismantling,including all peripheral activities, such asstorage and material handling, is coveredby a comprehensive safe system of work.
Hazard identificationIn the development of safe systems ofwork, the decision process should aim toidentify all hazards associated with theplanned activity and, if they cannot beeliminated, identify ways in which they canbe effectively controlled to an acceptablelevel of risk.
Significant hazards relating to edgeprotection include:
• Falls from height• Lifting & lowering of loads• Manual handling• Trapping• Inadequate working space• Structural instability• Inadequate access to height• Plant and machinery
32
10. Safety requirements
Edge Protection Federation Hollinwood Business Centre Albert Mill Albert Street Hollinwood Oldham OL8 3QP
06-2007/Q500
code of practicePrice: £10.00
edge protection
Edge Protection Federation
Code of Practice 2007
A Guide to the Selectionand Use of TemporaryEdge Protection Systems
Our thanks to the following Edge ProtectionFederation working group companies fortheir contribution to this document:
Construction SkillsC.J. O’SheaCombisafeEasi-EdgeIschebeck TitanK-GuardSafe Edge SGB Group
This guide has been produced to providehelpful advice and information to thoseconcerned with edge protection duringconstruction operations, but should not beused as a substitution for supplier guidanceor legal advice. It remains the responsibilityof the user to carry out risk assessmentsand follow safe procedures. The EdgeProtection Federation accepts no liability inrelation to any use or reliance made of anyinformation in this publication.
Edge Protection FederationHollinwood Business CentreAlbert MillAlbert StreetHollinwoodOldhamOL8 3QP
www.nepf.org
Issue no. 1
ContentsPage
1.0 Introduction 5
2.0 Scope 5
3.0 Definitions 6
4.0 Design and client issues 7
5.0 BS EN 13374: the European standard for temporary edge protection 8
6.0 Typical product types 10
7.0 Design features 10
8.0 Edge protection systems & products 11
8.1 Mesh Barrier Systems : Concrete Frame Applications 118.2 Mesh Barrier Systems : Steel Frame Applications 128.3 Net Barrier systems 148.4 Flat Roofing Free Standing Systems 158.5 Climbing Screen Protection systems 168.6 Tubular Guardrail solutions 17
9.0 Installation Guidance 19
9.1 Safe System of Work 199.2 Typical Method Statement Issues 209.3 Installation Guidance for Product Types: Concrete Frame 22
Steel Frame 26
Other Types ??
10.0 Safety requirements 32Legal framework 32Hierarchy of hazard management 32Summary of relevant Regulations 35
Temporary edge protection is used inconstruction work, primarily to preventpersons and objects from falling to a lowerlevel from working surfaces (sloped or flat)e.g. concrete slabs and other areas whereprotection is required.
In the UK, the Work at Height Regulationsgovern the requirements for prevention offalls and the hierarchy for solutionselection. These Regulations require theselection of collective passive measures,such as edge protection, in preference topersonal measures.
Classes specified within the EuropeanStandard BS EN 13374 are usedthroughout this guidance and referenceshould be made to this standard. They areintended to cater for the variedrequirements appropriate for differentuses.
This guidance has been written by leadingsuppliers and contractors within theindustry and is intended to provideguidance on the use of the variousalternative product types to provide safeedge protection in a large number ofdifferent applications.
It is important to recognise that edgeprotection performance is dependent onthe structure to which it is attached andconsideration of the loads and forces willneed to be taken.
Importantly, this guidance also advises onthe aspect to be considered whenselecting the safest method of installationof these products.
1. Introduction
5
This guidance covers existing best practicefor design, selection, safe installation anddismantling, inspection and maintenance,of edge protection used in both concreteand steel construction, as well as in manybuilding and civil engineering applications.This will include potential falls fromworking surfaces, e.g. slabs, roofs, liftshafts, pits or holes, plus staircases andsimilar parts of building structures.
Requirements for scaffold platforms ar notcovered and reference in this area shouldbe made to BS EN 12811.
This guidance specifically excludes edgeprotection to surfaces intended to protectagainst:-
Impact by plant or vehiclesContainment of bulk loose material(including snow)Access by the general public and theirprotection from falling.
2. Scope
Fall prevention system not designed to BSEN13374
Typical edge Protection systemdesigned to BS EN 13374
Anchor Sleeve: Component of drilledanchor system which is inserted intoconcrete etc. and expanded to supportheavy duty loads.
Beam Bracket: System socketcomponents on formwork beams whichsupport posts of edge protection system.
Bolted Frame ConnectionComponent bolted into steel framework ofbuilding, either prior to construction orassembled after initial construction.
Cantilever: Unsupported extension to amain platform.
Clamps: System components which areclamped horizontally or vertically toconcrete or steel structural members.
Concrete frame: Building frameworkconstructed primarily of in-situ pouredconcrete.
Counterweighted Systems: Systemcomponents which are not fixed orclamped, but rely on ballast/counterweights for stability.
Dynamic Loads: Impact or dynamicsuddenly applied loads.
Exclusion Zones: Area where access isprevented due to hazardous activity withinor above the zoned area.
Falsework: A temporary structure used tosupport a permanent structure while it isnot self-supporting.
Formwork: The section of temporaryworks that gives the required shape andsupport to poured concrete.
Leading Edge: Temporary edges or openedges of buildings/structures wherepotential fall risks exist.
Mesh Barriers: System protective barrierswith mesh infill.
Metal Decking: Profiled steel permanentformwork (prior to concrete pouring).
MEWP’s: Mobile Elevated Work Platforms(e.g. telescopic booms and scissors lifts).
Mobile Anchor: Deadweight /counterweighted anchors (to EN 795 Class E)for the attachment of personal fall protectionequipment.
Nets: Safety nets compliant to to EN1263-1.
PFPE/Harness: Personal Fall ProtectionEquipment (e.g. full body harness, lanyard,energy absorber and anchor point for fallarrest).
Posts: Principal vertical supports of edgeprotection systems to which guardrails,mesh barriers and toeboards may beattached.
Screen Protection: Storey height edgeprotection system that climbs vertically asthe building progresses.
Slab edge: Concrete floor edges.
Socket Bases: System base componentswhich are typically anchored into concreteslabs.
Static Loads: Horizontal and vertical graduallyapplied loads without any impact force
Steel frame: Building constructed primarilyof a steel framework.
System Classifications: Edge ProtectionClasses under BS EN13374.
Toeboard: Solid horizontal barrier providedlevel with the surface specifically toprevent the fall of materials or people.
Tubular Handrails: Guardrails constructedfrom traditional scaffold tube and fittings.
Free Standing Systems: Systems whichare not fixed or clamped.
3. Definitions
6
Within this Code of Practice there are alarge number of application solutions, withvarying products, but a common approachto safety standards. However, it is foundthat many of these systems can becompromised by circumstances found onsites from day to day.
Traditionally, edge protection would havealways been by means of tubularscaffolding and, therefore, usually installedby scaffolders. It has now become morecommon for purpose-designed edgeprotection systems to be used on manysites, for which more specific trainingshould be essential. It is important thatclients seek evidence of appropriatetraining qualifications for what is, clearly,one of the potentially more hazardousconstruction related tasks.
Within the Work at Height Regulations2005 there are clearly stated requirementsto consider working at height issues fromthe very inception of a project, and toproperly plan and organise work of thisnature. However, on a daily basis, risks arefaced which would be quite greatlyreduced if these directions from theregulations were followed.
There is an urgent need for designers andcontractors to consider the problemsposed by a myriad of designs, withinsufficient consideration for access eitherprior or subsequent to the buildingconstruction. This is a requirement underRegulation 13 of the CDM regulations
Examples of this include steel framedindustrial buildings with steel columncentres set at 8m and 9m centres, with nointermediate structural supports for edgeprotection, as many lack rigidity or are ofcold rolled section. Compliance with BSEN13374 has become very difficult due tolack of rigid fixing points.
Installation on steel framed buildings isincreasingly demanded to be secured bytelescopic boom, to avoid working atheight, yet the ground driving conditions
are often extremely hazardous at criticaltimes for access as pouring the groundslab is a later priority and there are manymaterial obstructions inhibiting the path ofMEWP’s.
Slab edge details can present additionalpotential fall risk problems which result inthe need to mount vertical extensionpanels to secure sufficient guardrail height.This is an undesirable adaptation that couldbe avoided by ensuring that regulationheight guardrails can always be installed atslab edges.
When the guardrail systems are safelybolted or clamped for the duration of theproject, the industry is now faced with theincreasing problem of component removalonce all the cladding elements are in place.The elements are effectively trapped,unless removed from lower floor levels bya variety of movable access platforms. Theoriginal installation may well have reducedthe risk of working at height, but theremoval stages could present fresh risks.
These and other issues are highlighted inorder to appeal to the industry to assistthe suppliers of safe edge protectionsystems to reduce the risks of working atheight through better organisation, designand planning.
4. Design and client issues
7
The publication of this new standard for edgeprotection has led to the launching of asignificant number of purpose-designedsystems for improving edge protection safety.
The Standard is the result of many years ofwork by specialists from several Europeancountries, including the U.K. Until it’spublication, the only reference work forthese applications was the rather limitedSIR15 – a specialist HSE inspectors report,which has been effectively out of date for anumber of years.
Edge Protection Classificationswithin BS EN13374
Edge protection systems are selectedprimarily based on the gradient of thesurface for which they are to provideprotection. The performance requirementsfor the various classes are detailed withinthe standard BS EN 13374 thus:-
Class A:Provides protection to flat surfaces andslopes generally up to 10º. It providesresistance to static loads and is based onthe requirements to support a personleaning against, walking beside, and possiblystumbling against the edge protection.
Class B:Provides protection to flat surfaces andslopes, generally up to 30º, and to evensteeper slopes with short slope lengths. Itprovides resistance to both static and lowdynamic loads and is based on therequirements to support a person leaningagainst, walking beside, possibly stumblingagainst and sliding down a sloping surfacetowards the edge protection.
Class C:Provides protection to steeply slopingsurfaces, generally up to 45º, and up to 60ºfor 5m slopes. It provides resistance tohigh dynamic loads only and is based onthe requirements to contain a personsliding down a steeply sloping surface.
The above graph indicates the normalexpected application range for the differentclasses of edge protection. It appears in aninformative annex to BS EN 13374 and, assuch, compliance with the graph is not arequirement of the Standard. There is,therefore, a degree of freedom left toselect classes and systems for moreshallow slopes than those indicated withinthe graph, where the specific hazardidentification and risk assessment mightsuggest the use of a class with a steepergradient capacity.Further clarification of the detailedclassification requirements can be foundwithin BS EN 13374.
5. BS EN 13374: The British/ European standardfor temporary edge protection systems
8
Loading requirements for class Asystem in BS EN 13374
Class C
Seepages11-12
Seepages9-10 &16-19
Height from guardrail Roof inclination
Class B
Class A
Loading requirements for class A system from BS EN 13374
9
With the publication of BS EN13374, anumber of new products and methodswere introduced, and innovation continuesto be a feature of this part of the industry.
There are several different types, whichcan be classified as follows:
This schedule illustrates the methods thatare used for each of the BS ENclassifications, by application.
Class A systems (for flat and slopingsurfaces up to 10 degrees) must resist ahorizontal force of 0.3kN anywhere on thetop of the guardrail arrangement, whilstmaintaining elastic deflection within55mm. They must also accept a verticalforce of 1.25kN applied as an accidentalloading. Type A systems may take theirsupport from clamping, drilled anchors orcounterweighted methods.
Class B systems, generally for slopingsurfaces up to 30º, must resist the samestatic loading requirements for Class Aand, additionally, must pass a low dynamictest using a swing bag. This test appliesimpact energy of 0.5kJ to the top rail and1.1kJ to the lower areas.
Class C systems are for more steeplysloping applications (see classifications)and are required to only resist a highdynamic test using a rolling cylinder. Thistest applies impact energy of 2.2kJ to thesystem. The prime consideration is toprevent the person falling, irrespective ofthe initial damage sustained by the barriersystem.
Wind The normal wind velocity pressure withinthe standard is 0.6kN/m2, which coversmost wind conditions in Europe. However,each application should be considered onits own merits and advice should besought from the supplier on theappropriate factor to apply. Variations willinclude the physical location, the height ofthe structure and the duration that theedge protection will stay in place.
The standard assumes a wind velocitypressure based on 40m height.
6. Typical producttypes
7. Design features
10
APPLICATIONS CLASSA
CLASSB
CLASSC Method
Bridge decks Drilledsocket/clamped
Concrete frames Drilledsocket/clamped
Steel frames Bolted/clamped
Formwork decks Clamped
Stairways Bolted/Clamped
Flat roofs(up to 10°)
Counterweighted/bolted
Sloping surfaces(up to 30°) Bolted/clamped
Steeply slopingsurfaces Bolted/clamped
88..11 MMeesshh bbaarrrriieerr ssyysstteemmss((CCllaasssseess AA && BB))
Mesh barrier edge protection systems arefall prevention systems that offer a highlevel of protection through a full mesh-infilled guardrail and a performance-testeddesign to BS EN13374. The mesh infill istypically heavy-duty mesh and, therefore,superior to similar products previously usedsolely for materials retention. Toeboards aretypically integral to each panel.
Applications & surfacesThese types of systems are suitable foruse on a wide variety of applications, asthere are accessories for fixing to concreteslabs, upstand beams, steel girders,vertical walls, staircases, formwork beamsand to many other surfaces. In addition,these systems are used for site pedestriansegregation. In many cases, the fixingcomponent is specific for the purpose.However, the mesh barriers and poststend to be used more generally.
Range of adjustment: Slab clamp Clamping components will generally adjustwithin a range of 100 to 600mm, but sizesbeyond this may be available for specialrequirements. Steel joist/ girder clampingcomponents may operate within a smallerrange as these are cantileveredapplications and, therefore, may have tosustain more onerous forces. Clampingcomponents may be capable of being usedboth horizontally and vertically (slabs andupstands), with minor adjustments.
8. Edge protection systems and products
11
Typical mesh barrier components forconcrete slabs
Mesh barrier assembly
Mesh Barrier
Post
Socket base
Slab clamp Beam clamp
Formworkbeam
Anchor loadings: Socket basesTypical socket base situations may imposean anchor tensile load of approx 6kN and ashear load of at least 0.3kN for a 1m longpost. For longer post applications, thesupplier will provide information andguidance. It is extremely important thatanchors are selected, positioned and setstrictly in accordance with themanufacturer’s instructions.
Edge protection for steel framed commercialbuildings has usually been problematical for theinstallation tasks, as there is no flat concreteslab to work from until the flooring is laid. It isimportant that protection is in place at theearliest stage and this can be hazardous.Recently, a new range of equipment hasbecome available which can be clamped,bolted or welded to the horizontal floorsteelwork. The fixing of these components canbe done beforehand, prior to construction, or bymeans of telescopic/articulating booms orsimilar to avoid operatives working in moreexposed conditions.
Installation and removal by MEWPIncreasingly, installation in conjunction withMobile Elevating Work Platforms (booms) hasbecome more favoured, although new safetyprocedures and techniques need to becomeestablished. The removal of the installedcomponents at a later stage is also a matterthat requires close attention to avoid otheraccess risks from working at height duringinternal fit-out stage.
Comprehensive installation advice for steelframed applications is featured later in thisdocument.
Edge protection on steel framed buildings oftenrelies for its support on the vertical columnsand these have, in recent years, become moreand more widely spaced as the design of theother elements have been optimised. The othercomponents of the building will often lack thestructural integrity to support the forces arisingfrom BS EN 13374.
In considering the building structure, it is likelythat hot rolled sections will have sufficientstrength, but cold rolled sections should becarefully checked. Where other buildingcomponents are employed (e.g. purlins), it isimportant to determine that their strength anddeflection characteristics will enable theguardrail components to comply with BS EN13374.
Over spans of 7, 8 or even 9 metres, it is difficultto meet the deflection requirements of Class Asystems without specially designed solutions.
12
Upstand Beam Slab Clamparrangement
Slab clamp arrangement
Socket base assembly.
13
Connecting to vertical steel columns
Clamping to horizontal beams
Purlin clamps
Bolting to horizontal beams
8.3 Net barrier systems(Classes B&C)
Net barrier systems are fall arrest systemsconstructed of energy absorbing safetynets, to combine fall arrest and a highdegree of containment. They comprise asafety net spanning between intermediatesupport posts that can be set at largesupport centres. They have specific cornerassemblies and access routes into theprotected area.
Applications and surfacesNet barrier systems are typically used withsteep or curving roofs and also in largebay-sized industrial roofs where the abilityto meet the static test deflection criteria ofClass A and B is complicated by the baysize.Net barrier systems are also usedextensively in stadia building and in otherapplications .
Design features - net barrier systemsNet barrier systems are typically Class Csystems with no requirement to satisfy thestatic test within BS EN 13374. The testdoes, however, require a minimumdeflection criterion to be achieved in orderthat the system absorbs the requireddynamic loading They are formed using asafety net, sometimes supported on a toprope or cable, to provide an energyabsorbing edge protection system forsteep slopes. Systems can combine theedge protection with an eaves overhangfall arrest solution, linking into the buildingor the internal under-slung safety nets.
They are typically set at a high levelrelative to the working surface, to ensurefull containment in spite of their flexibilityin the event of a high dynamic fall. In viewof their high level, access points need tobe made through the net to provide accessto the working area.The intermediate support arrangementsnormally secure to the primary structure atbay centres and have a high degree ofadjustability to accommodate various eaveand verge details. The corner arrangementstake much of the impact load and so arestiffened with bracing etc.
ComponentsSafety net (combining overhang) Top rope/cableIntermediate support arrangementCorner arrangementAccess point
PerformanceLarge bay sizes can be accommodated,with intermediate supports up to 10mapart.Eave and verge overhang limits willdepend on the structure, the systemchosen and its method of attachment tothe building. As the overhang increases,the attachment point can move from thecolumn to other suitable secondary anchorpoints.
Wind loading is an important performanceand capacity issue, which also affects themaximum intermediate support spacing.This can have a bearing on the maximumheight at which the system may be usedand can also limit the use of fine meshoverlays for a higher level of small materialcontainment.
14
Net barrier system
8.4 Freestanding Systems(Class A)
Free standing weighted edge protectionsystems are designed to comply with theClass A requirements of BS EN 13374, butare based on different supporting principlesto mesh barriers. The freestanding systemswere previously designed to SpecialistInspectors Report No.15, but thatdocument is no longer valid.These systems derive their support fromweighted components, fixed to lever armsand connected in turn to barrier frames atthe edge of the building.
Applications and surfacesFlat roofs are defined as having slopes of10 degrees or less, but may have a varietyof surfaces, including concrete, roofingfelt, bitumen, solar coatings or similar.Freestanding edge protection systems maybe installed to provide protection forinspection, access to plant, or formaintenance or new roof covering work. This type of system is not generally suitablefor profiled industrial roofs, although specialadaptations may be available. In addition,some types of surface may presentparticular problems: e.g. pebbles, granularloose materials and those that lack frictionalresistance. Wet or icy conditions areparticular hazards and some Class A testsattempt to simulate wet surfaces.
Design featuresThe weighted systems all have oneimportant feature in common; they avoidpenetrating the roof surface in order toresist movement. This avoids the likelihoodof roof leakage. The Barrier designs haveelements which allow them to fit anyrectangular shape. Curves can also becatered for in some instances.
Components
FramesHorizontal linking tubesWeightsTubular lever armsBasesToeboards
The amount of ballast may vary fromproduct to product, but would typically bein the 20 to 50kg range. The length of leverarms will also vary.
When roof covering is taking place, edgeprotection can interfere with production,and, in most cases, therefore, the weightscan be temporarily removed. It is veryimportant to closely follow themanufacturer’s instructions concerning theremoval of weights to preventcompromising the systems ability toperform safely. In some cases, thecounterweights have arms that can belifted to raise the weight clear of thesurface.
The moving of ballast weights has ManualHandling Regulations implications, so themovement of them should be minimised.
Proprietary handrail fixings may beincorporated into projects in order to addflexibility to systems.
Performance
These product types should satisfy therequirements of Class A, to BS EN 13374.However, due to the inability to resistdynamic loads, they are unlikely to satisfyClasses B or C.
15
Freestanding system
WindThese systems are generally designed tobe freestanding and capable of resistingmoderate wind loadings (e.g. 40 to 50mph)but the wind profile will be adverselyaffected when toeboards are incorporated.This would be a legal requirement formaintenance tasks or new work, but forlong-term use has been known to beomitted if not a working area. In someinstances a wind calculation report may berequired to demonstrate the performanceof the system. Additional ballast oradditional fixings may then be required.
ProximityThe freestanding edge protection systemsmay be employed at the leading edge ofthe roof, as a visual barrier or as walkwayarrangements between roof plant. The safedistance from the roof edge will vary fromproduct to product and advice should besought from suppliers to determinewhether they recommend a safe minimumdistance from the roof edge.
8.5 Climbing screen protectionsystems
Storey height climbing screen protectionsystems enclose the perimeter of thebuilding by means of mesh or plywoodscreens. Vertically, the screens coverbetween 21_
2 to 31_2 floors in height and are
built in sections, horizontally, and thencrane handled, vertically, into position asthe concrete frame structure progresses.
Applications This product type is suitable for mostconcrete frame structures, but may limitthe choice of formwork system that can beused.
Economically, the system should be usedon buildings over eight storeys in height.
Design features This system is anchored to the structurethroughout the construction period, givingpositive relocation of the screens as thestructure progresses. Improved protectionis given to workers on the wet slab andalso on slabs below, where followingtrades are working.
Back propping is normally required onfloors below, at the needle positions.
The screens are normally bolted to a pairof vertical soldier members which sit ongravity support shoes, connected toneedle supports that are, in turn, anchored
16
Climbing screen system
to the concrete slab. The typical screenarea that can be lifted is 4.8m wide x10.5m high. Platforms can also beaccommodated in the screen design forpost-tensioning operations..ComponentsScreensSoldiersNeedlesRecoverable anchors
Performance
These product types are normally designedto satisfy the requirements of Class A andthey offer a high degree of materialcontainment.
Careful consideration of the wind loadingon these product types is required,particularly as the building heightincreases.
The performance of these systems relieson the correct selection and installation ofappropriate anchoring components.
8.6 Tubular guardrail solutions(Class A)
We recommend that guidance is alsosought from the NASC documentSG27:06- Temporary Edge Protection onOpen Steelwork, which covers a numberof issues arising from the installation oftube and fitting guardrails.
These methods/systems comprise twobasic types:
1. Traditional scaffold tube and fittings.2. Purpose-designed clamp on systems.
Traditional scaffold tube and fittings:components Scaffold tube and fittings are the traditionalcomponents for constructing slab edgeprotection. Short length tubes are used forthe support posts, ties and bracingmembers, whilst tubes up to 6.4m inlength may be used for the handrails. Thetubes are connected together by means offittings and the support posts shouldinclude a base plate.The toe-board is normally a 3.9m scaffoldboard which should be fixed to the supportpost by means of a toe-board clip. If used as a free-standing edge protectionsystem, concrete blocks may be requiredto stabilise this arrangement, althoughmany free-standing tubular guardrails areemployed primarily as a visual barrier only.
Traditional scaffold tube and fittings
17
Applications and surfacesWhilst virtually all of the purpose-designededge protection systems will meet theperformance requirements of BS EN13374,the situation with tubular guardrails fromtraditional scaffolding requiresconfirmation. The reason for this is that,whilst systems are modular, and usually atpre-determined centres, tubular guardrailposts are variable in location.
On concrete frames, individual socketbases are often used in conjunction withtubular scaffolding to reduce the need forclamping steel tubes to the slab edge. Ifthese are not part of a recognisedproprietary system, evidence of theircapability should be sought.Tube and fitting guardrails can be suitablefor many edge protection requirements,and their performance to Class A canreadily be shown by calculation.
Design features: Tube & fittingsTube and fitting components are flexible andare capable of adaptation to virtually anyshape. The slip load of 6.25kN per fittingneeds to be accommodated and is onlyachieved with the correct torque setting.
Traditional free standing systems in an ‘A-type’ frame arrangement arerecommended to be designated only as avisual barrier if set back from the edge. Thistype of arrangement is not considered tobe adequate for fall prevention at an edge.
Containment nets and sheets arefrequently used to infill the guardrail andincrease the level of containment.However, the increased wind load must beconsidered and accommodated within thecalculated design.
Lightweight steel mesh panels (brickguards)can be used to contain materials. However,these need to be closely controlled as theyare easily moved out of position. A toe-boardis used to further contain small items, and isnormally a scaffold board fitted on edge.
ComponentsScaffold tubes (typically various set lengths)Scaffold fittings (fixed, swivelling, andvarious specials for particular applicationsScaffold boards (used as toe boards)Base plates
Purpose-designed clamp-on systems Edge Protection to profiled steel roof
Purpose-designed clamp-on systems mustmeet the criteria laid out in BS EN 13374.They are specifically designed for clampingto steelwork sections, usually at full heightroof level, but can also be used atintermediate floor levels.
They would normally incorporate aluminiumor steel tube/lattice beams to form a guardrailthat must comply with the dimensionsspecified in the WAH regulations.
Safety nets can be attached to the systemto give additional protection for roofworkers and to prevent objects falling fromthe roof but the system must be tested forthis purpose.
Performance
Wind forcesWherever mesh, sheets or infills areinstalled, it is important to assess theimpact on wind forces, as these could addconsiderably to wind pressures that needto be resisted.
Wind pressure is based on a structure witha maximum height of 40m, in accordancewith the criteria set out in BS EN 13374.Where wind is shown to be the governingforce, the supplier should supplycalculations to show the system is capableof withstanding the loads generated.
18
9.1 Safe systems of Work
All edge protection activities, in commonwith most other construction activities,should be undertaken in accordance with asafe system of work. A safe system ofwork is a formal procedure that resultsfrom a systematic examination of a task toidentify all of the hazards and assess theconsequent risks. It is a means of ensuringthat, wherever possible, hazards areeliminated, or otherwise minimised, by theapplication of appropriate controlmeasures.
It has been estimated that at least aquarter of all accidents at work involvefailures in systems of work. Therefore, it isessential that the entire process of edgeprotection erection and dismantling,including all peripheral activities, such asstorage and material handling, is coveredby a comprehensive system of work.
See the hierarchy of control measures onpage 34
Use of site facilities/main client duties
In order to safely install edge protectionsystems there are a number of areas inwhich installers will benefit from thesupport and co-operation of the maincontractor. It is in these areas that there isa need to clearly communicate the aspectsof site activity that will aid the safe,speedy installation and removal of suchsystems:-
Involvement with design team tominimise need for special components toovercome building obstructions. Facilitatepre drilling steelwork for ground basedassembly.
Formation of well-compacted surfacesand roadways.
Operators of MEWPs to be IPAF orCPCS trained.
Co-ordination of crane lifts. Access tocrane at agreed times.
Exclusion zones to be established duringinstallation
Weekly inspection regime.
No interference with installedcomponents except by nominatedpersons.
Access to building frame to facilitateremoval. May require scaffold, mobiletowers, scissor lifts or mast workplatforms.
Storage during stage by stagedismantling to avoid loss of or damage toequipment.
Risk assessments
In the development of safe systems ofwork, the decision process should be ledby hazard identification and theassessment of associated risks. which, ifthey cannot be eliminated, must beeffectively controlled.
Significant hazards relating to edgeprotection include:
Falls from HeightFalling MaterialsManual HandlingInadequate working spaceInadequate access to heightLifting and lowering of loadsPlant and machinery operatorcompetenceStructural integrity
Also see page 33 for illustrations oftypical hazards.
9. Installation guidance
19
9.2 Typical method statementissues
The following items identify many of theissues that, typically, are required to becovered during the installation and removalof edge protection.
Site inductionAll personnel working on or visiting thesite on a regular basis should report to themain contractor to attend a site induction.This induction to be held on first day ofoperating on site.
Site labourAll operatives are required to becompetent in the erection anddismantling of edge protection, and arefamiliar with site procedures. Alloperatives should carry evidence ofcompetence to install the system beinginstalled; evidence to use any access orlifting equipment and general site safetyawareness by way of a CSCS card orsimilar.
AccidentsAny accident, however slight, to bereported immediately to the main siteagent and entered into the site accidentbook. If the accident or injury falls withinthe requirements of RIDDOR regulations,it shall be reported.
Access requirements/site conditionsSuitable roadways and access routes areto be provided and maintained to allowtransport to gain access from the publichighway to the working area. The groundconditions within the working area shall beestablished and maintained in a suitablecondition to support the access (e.g.MEWP’s) and lifting equipment.
Working areasOnce the start point and gridline havebeen determined, the main contractor shall ensure that no other personnel workeither under or in full-fall risk areas. Theseareas should be monitored closely by themain contractor and adjusted to suitprogress.
Where work is being undertaken that maycause materials to fall onto persons
passing below, install adequate means ofisolating the areas below the workactivity.
PlanningDetailed planning of the work canalleviate the need to work at height,through pre-installation of systems.Examples are indicated later within thisguidance.
When working on the edge, installers mayneed to wear a safety harness. When themethod of work requires the specificationof a harness, both the lanyard and theattachment point must also be includedwithin the method statement.Consideration should also be given to theneed for a rescue plan and the necessaryequipment required.
CompetenceHaving established a safe system of work,only those competent to carry out thework should be employed and they shouldfollow the method statement.
Adjustment/temporary removalIf the system needs to be temporarilyremoved to allow other work to beundertaken, the unprotected area shouldbe secured by other compensatorymethods and the system should be re-instated as soon as practical by thosesufficiently competent to reinstate it.
Setting outThe system should be set out inaccordance with the system supplier’sinstructions and in accordance with therelevant class requirements from withinthe standard BS EN 13374. The minimumheight requirements of 1m and themaximum gaps required by the relevantclass should all be satisfied.
HandoverOn completion of an area, the installershould complete a handover certificate andleave a copy with the main contractor’ssite agent. Following handover, theinstalled system will require regularinspection by the user.
20
Installation optionsInstallation options include many methods.The table above indicates the mostcommon usage.
General GuidanceAlways check material being used fordamage. Damaged items are to bereplaced immediately. Always use the same system and do notmix and match between systems as allhave different specifications.Edge protection systems are not designedfor the attachment of fall arrest devices,nor are they designed to provide supportto building materials.Ensure type or class of edge protectionmeets the specifications that are requiredon site for the specific applications.Edge protection systems should not beadapted or altered in any way, other thanby a competent person and in line with themanufacturer’s approval.
GapsIn general, gaps in edge protection shouldbe kept to the minimum. Below theprotective barriers, toeboards or nets,they should be as close as practicable to20mm, to prevent loose materials fromsliding underneath. Gaps in the edgeprotection should be sufficiently small thata person cannot fall through.
21
Drilledanchors
Cast-inanchors Clamps Formwork
beamsVertical
surfaces MEWPs Columnsecured
Free-standing
Concrete frame
Steel frame
Sloping roof
Flat roof
9.3 Installation guidance forconcrete frames
Drilled anchorsThe selection of a suitable anchor will bedependent on both the system beinginstalled and on the base materialavailable. The system supplier can adviseon suitable anchors and can confirm theload imparted to the anchor with thevarious socket bases and configurations.
The strength, thickness, age and type ofconcrete all have a bearing on performance,as do the edge distance, depth ofembedment and the proximity to otherfixings. In all cases, the anchormanufacturer’s instructions must be closelyfollowed to achieve the desired capacity.
AnchorsAnchors used in the support of edgeprotection are frequently heavily loadedand all five key anchorage performanceareas need to be carefully considered:
• Anchor edge distance,• Anchor spacing,• Depth of embedment, • The base material itself.• The load on the anchor is influenced by
the geometry of the system and theattachments as well as by the thicknessof the slab and application geometry.
Additionally, wind loading and combinationloading must be considered.
Effective anchorage solutions mightinclude the use of cast-in channels or otherfixings that are placed for the permanentworks, but that can be utilised for thetemporary works in supporting the edgeprotection. Their ability to accommodatethe loads imposed by the edge protectionsystem must be confirmed.
Having selected an attachment point onthe slab surface or wall face, it is equallyimportant to consider the impact such alocation has on the effectiveness of thetoeboard containment. Panel type systemswill frequently lose effective toe boardheight, within the depth of the slab or bypositioning the attachments down the wall
face, below the wall top. The ENrequirements for minimum toeboard heightmust be maintained and equally the needto contain the 20mm sphere must also beconsidered.
The other consideration in selecting suchan attachment position is the overalleffective height of the edge protection. Theminimum height of 1m (In accordance withBS EN 13374) must be maintained at allstages of the construction process. Thismay result in the need to “top up” theedge protection system with additionalheight (in both posts and panels).
Slab socket base
• When working at an edge, the operativemust wear a suitable safety harness andlanyard, which has been inspected and,in turn, should be anchored to a suitablepoint in the structure in accordance withthe safe use of the fall arrest system.
• Before installing the anchors, measureand identify clearly the location for eachsocket base.
• Socket bases should only be installedinto sufficiently cured concrete slabs.
• It is normal practise to install anexpanding sleeve type anchor and holediameter and depth should be to themanufacturers instructions.
• It is normal practice that the hole isdrilled no less than 200mm+/-50mm infrom the slab edge. However, at alltimes, reference must be made to boththe system installation instructions andthose of the anchor manufacturer.
• The anchor sleeve must sit flush with theslab surface and not above (if anchor sitsproud then check the hole for debris anddepth and then re-locate). See illustration.
• Set the anchor with the setting tool andhammer the tool until solid resistance isencountered.
• Ensure the thread on the socket base isfree from defects and/or damage, thenthread the socket base into the surfaceand tighten according to supplier’srecommendations.
• Socket base centres and edge distancesshould, at all times, be set out inaccordance with the systemmanufacturer’s requirements.
22
Cast-in sockets are mostly used incomposite type construction, either withprecast units or with metal decking. Thesetting out and positioning of the socketsmust be carefully planned and must followthe system manufacturer’srecommendations. Best practice wouldinclude, where possible, the opportunity topre-install the complete system prior tolifting into position.
It is also important to consider thechanges in working surface level, at thevarious stages of the construction process.The overall height requirements within theEN standard must be maintained, as mustthe containment limits.
• When working at an edge, the operativemust wear a suitable safety harness andlanyard, which has been inspected and,in turn, should be anchored to a suitablepoint in the structure in accordance withthe safe use of the fall arrest system.
• When planning and installing edgeprotection for precast unit placement,consideration should be given to thelocation of the anchors for the edgeprotection relative to the floor layout.
Effect of concrete topping The edge protection may also need to belifted to maintain its minimum height forthe topping pour. The principle being tominimise movement and change to theedge protection, whilst maintaining bothheight and toeboard containment.
23
Vertical surfaces.Where edge protection systems need tobe fastened to vertical surfaces, such asslab edges or walls, consideration at thedesign stage should be given to the typeof anchor and its suitability to the loadingapplication. The anchor will be subject tocombined loading from both shear andtensile forces resulting from self weightand other superimposed load as well asmoments due to handrail and windloading. The strength of the surface intowhich the anchor is fixed is a majorconsideration and, where any doubts, existthe strength should be confirmed by pullout tests or other approved means.Reference should always be made to theanchor manufacturer.
Gaps between the vertical surface and thehandrail/toeboard should be controlled andkept to the minimum as required by BS EN13374. The installation should be carriedout by trained personnel, wearing asuitable safety harness and lanyard whichhas been inspected and, in turn, anchoredto a suitable point in the structure inaccordance with the safe use of the fallarrest system. Alternatively MEWPs maybe suitable for access.
Cast-in Anchors and cast-in SocketsIf proprietary anchors are to be insertedinto floors prior to pouring, themanufacturer’s recommendation should beclosely followed. It will be important toproperly secure anchors, to preventmovement and ensure that the anchorresult is both vertical and flush with thefinished slab.
Socket base installaion
Anchor installation
Anchor proudof surface
Anchor installedout of plumb
Anchor correctlyinstalled
Socket base proud of surface
Socket base installedout of plumb
Socket base correctly installed
24
Clamps Various clamps and attachments can beeffectively used to maximise flexibility and toavoid drilling or penetrating the structuralelement. Clamp systems, fitted in accordancewith the manufacturer’s instructions, requiremore space to provide adequate support, andcare must be taken to avoid conflict withother trades such as with cladding.
• When working at an edge, the operativemust wear a suitable safety harness andlanyard, which has been inspected and,in turn, should be anchored to a suitablepoint in the structure in accordance withthe safe use of the fall arrest system.
• Check the design to ensure that thestructural element will have sufficientstrength to accept the loads from theclamps.
• Where the finish may be sensitive, careshould be taken to minimise the impactof the clamp on finishes.
• Where possible, clamps should besecured against inadvertent releaseduring the installation process. Use oflanyards or ties should be considered.
• Measure and identify the intendedlocation for each clamp and post
• Determine the approximate depth of theslab and, initially, adjust clamp to within100mm of this figure.
• Hook clamp over the slab and position toobtain full contact against the edge.
• Adjust clamp to fit by turning handlefirmly to clamp rigidly into place on theslab floor. Test for movement and, ifnecessary, tighten again.
Formwork beamsProprietary brackets are available that lockonto the upper or lower surfaces ofaluminium or proprietary timber formworkbeams to provide a socket or other meansof clamping a vertical handrail post. Thesebrackets can be pre-fixed onto theformwork beams during the initialformwork erection procedure and canremain in place during formwork or tablemovement, thus providing a handrailfacility at all stages of the formwork use.The brackets must be fitted in accordancewith the manufacturer’s instructions atcentres that are adequate to sustain theforces exerted onto the posts, via meshbarriers or handrails, due to wind andhandrail loading.
• When working at an edge, the operativemust wear a suitable safety harness andlanyard, which has been inspected and,in turn, should be anchored to a suitablepoint in the structure in accordance withthe safe use of the restraining system.
• Ensure all beams are free from damageor distortion of the web and at the ends.
• Ensure all beams are securely fixed tothe falsework/formwork structure.
• Fix bracket to manufacturer’s instructions.The centres of the brackets should be atleast 150mm in from the end of the beam.
• The horizontal spacing of brackets shouldfollow the system manufacturer’srecommendations.
• Brackets should only be fixed to beamsthat are at right angles to the meshbarrier direction.
CantileversCantilever applications, whilst in commonuse, need further design considerationswith particular regard to stability, loadingand deflection criteria, both during theinitial erection and in the intended finalapplication. Formwork beam brackets can,again, be utilised on these applications, butthe deflection on the beams, due to thecombined loading from concrete and theadditional moments from the handrailloading, need to be considered by thetemporary works designer.
The brackets must be fitted in accordancewith the manufacturer’s instructions atcentres that are adequate to sustain theforces exerted onto the posts, via meshbarriers or handrails, due to wind andhandrail loading.
25
Installation guidance for steelframes
In accordance with the recent Work atHeight legislation, hierarchical controlsmust be employed to reduce, or preferablyeliminate, the need to work at height. It is,therefore, recommended that where siteconditions allow, ground level, pre-determined installation of edge protectionsystems is utilised.
PlanningIn order to build the edge protection atground level, it is important to determine:• Whether clamping or bolting components
will be selected.• That the steel sections have the
appropriate properties to resist the loads.• If components are to be pre-bolted, the
section size will be compatible with thesize of the component.
• That there is a reliable process for anypre-drilling during manufacture.
• The craneage facility will maintain thebalance of the beams to avoid rotation.
Pre-installation• Ensure adequate knowledge of the
system has been gained prior to anyinstallations, including fixing operationsand component sizes.
• Prior to any craning or manual handlingactivity, consideration should be given toidentifying each component weight.
• All appropriate site risk assessmentsshould be developed and communicatedto all relevant parties.
• Implement the necessary exclusionzones.
• Where appropriate, netting should beutilised.
• For MEWP equipment (e.g. telescopicbooms) the site should be prepared bymeans of suitable hard core surfaceswhich have been consolidated andlevelled.
WeatherConsideration should be given to weatherconditions that could have an adverseeffect on the craning and installation of theedge protection. (Refer to the BCSA guide,erecting steel in windy conditions)
Pre-attaching systems to steelwork:• Confirm that pre-drilling of steel sections
are to the correct spacing. • Securely fix components into position
following manufacturer’s fixing details.• Make positional (i.e. vertical) adjustments
prior to attachment to the steel frame. • Ensure that minimum gaps would be left
between the final working surface levelsand the underside of the barriers,removing, where possible, the need tore-position the system at a later stage.
Sacrificial socket
26
• Ensure that component positioning willpreclude the need for operatives to leanthrough the edge protection.
• Measures should be taken to ensure thenecessary working clearances areprovided for the fixing of edge trims etc.
• All components to be lifted in a MEWPmust have a reliable securing method toensure that they cannot accidentally bedislodged during lifting or during fixingoperations.
• Insert guardrail posts • Add mesh panels following
manufacturer’s methodology.• Ensure that guardrail height meets
regulatory requirements.
Mobile elevating work platformsMEWP’s installationMEWP’s can be used for access to installthe edge protection system in a largerange of applications. They can be used toinstall tubular guardrail solutions or otherseparate component systems when all thework is carried out at height. They can beused to complete a mesh barrier typesystem that has been partly installed tothe structural elements prior to lifting. Theyare also most commonly used to install netbarrier systems, where the intermediatesupport points are typically installed on thecolumn heads and then the safety nettingis strung between the supports tocomplete the system.
General guidance
• MEWP’s should not be used other thanby suitably trained and competentoperatives, who can evidence theircompetence and training.
• When working within a boom typeMEWP, the operative should wear a fullbody harness together with a fallrestraint lanyard, which may benefit froma shock absorber, of such a length thatthe user cannot climb up or out of thebasket whilst attached to the designatedanchorage point.
• The ground conditions within the wholeworking area should be established andmaintained in a suitable condition tosupport the MEWP and any liftingequipment required. Specific attention isfrequently required around the buildingperimeter.
• Care must be taken to ensure that thecombined weight of the operative, thetools and any equipment at no timeexceeds the capacity of the MEWPbeing used. Long or large componentsmay require the specification ofalternative MEWP’s or the use of liftingequipment.
• The area around and below the MEWPshould be access restricted to limit thehazard of falling materials and tools.
• All hand tools and other accessoriesshould be secured against falling, as theypresent a hazard to those passing below
Installing clamping components from aMEWP:• Ensure that steel sections are suitable
(see Planning)• Check capacity of MEWP relative to
weight of individual components• When working from a MEWP, a full body
harness (Restraint) must be worn,attached to a secure anchor pointdesignated for this purpose.
• A rescue plan should be produced torecover operatives in the event of a fall.
• All components to be lifted in a MEWPmust have a reliable securing method toensure that they cannot accidentally bedislodged during lifting or during fixingoperations.
• Position and rigidly secure clampingcomponents at recommended spacing.
• Insert guardrail posts in the appropriateposition.
• Ensure that guardrail height meetsregulatory requirements.
27
Crane slinging edge protection systemsSlinging and positioning of the steel beam,complete with the edge protection, shouldbe carried out with consideration given tothe possible rotation and imbalance of theload.
Measures should be taken to ensure theedge protection itself is secured to thesteel frame components during lifting.
Securing the load to the primary liftingdevice by means of secondary chains andties is suggested, as is following existingbest practice with regard to positiveconnection lifting.
.Tubular guardrail solutions onsteelworkIf tubular guardrails are to be installed bytraversing the steelwork, there areparticular issues, as this can be aparticularly hazardous operation. Werecommend the procedures outlined in theNASC document SG27:06 - TemporaryEdge Protection on Open Steelwork.
Installing tubular guardrails from mobileelevating work platforms• Great care and site specific prior approval
must be sought to lift and handle longtubes from a boom type MEWP basket.Handling materials such as this must bethe subject of a specific risk assessmentthat ensures that they can be safely liftedwithout risk of dislodgement or ofoverloading the platform.
• There must be a means of ensuring thatthe tubes remain secure throughout theoperation. Suitable measures to preventthe tubes rolling during manoeuvring ofthe MEWP should be adopted, such asfeeding the tubes through the basketguardrails. However, the guardrails maynot be suitable for vertical loadingwithout additional measures.
• Lighter materials than steel should beconsidered, such as aluminium, to easemanual handling issues.
• Great care is needed in the control of theMEWP, as the long tube componentsextend the basket width substantiallyand present impact hazards over a largearea.
• Temporary clips or open fittings can beused at the standards, to partially
support the tubes, whilst sliding intoposition and connecting.
• Consideration should be given toaccessing steelwork for fixings, as someof the bolt fastenings may be in difficultpositions to ensure adequately torquedfittings.
• Maintaining a clear area below theoperations is of increasing importance,as the risk of falling materials increaseswith the component size.
• Avoid over-reaching and climbing out ofthe platform.
• Consideration should be given to theprevailing weather conditions, which mayaffect the stability of the platform andequipment.
Mesh barrier type solutions• Lifting and handling mesh barrier panels
within a boom type MEWP can presentconcern, due to the weight and size ofthe panels. Early consideration should begiven to barrier component weights priorto selection of MEWP.
• Site specific prior approval must besought to lift and handle mesh barrierpanels and methods of safely,temporarily securing or restraining thebarrier panels should be considered.
Net barrier system solutions• Pre-assembly or part pre-assembly of the
components will reduce work at heightand ease the use of the MEWP.
• The net barrier is installed longitudinallyunder tension and normally fitted into thefall arrest netting system within thebuilding, having previously installed thecorner elements, and the intermediatesupports. This requires a larger and morerapidly changing exclusion zone to beestablished below the work area, andalso renders the installation even moresensitive to ground conditions.
• Suitably trained and competent installersshould always be used, who shouldstrictly follow the system manufacturersguidance. In most cases they will also beFASET trained in safety net rigging, andFASET best practice should also befollowed.
2 floors in height requires carefulplanning. Choice of anchor type isdependent on system being employed andshould be installed as per the supplier’sinstructions. As these systems arenormally used on taller structures, windloading is critical, especially when plywoodor monoflex is used as the screen face.Back propping to the concrete slab isrequired due to imposed loads from thescreen system at the needle positions.
• During assembly and dismantling of thesystem, operatives must wear theappropriate PPE at all times.
• Needles are anchored to the slab oncethe concrete has acquired sufficientstrength to carry imposed loads.
• Screens to be erected in a suitableassembly area on site or off site for partpre assembled delivery.
• Due to self weight of components,provisions should be made formechanical handling during on-site or off-site assembly. This would also applywhen dismantling system at completionof project.
• Only suitably trained personnel should beused for screen assembly.
• Lifting sequence must be carefullyplanned in accordance with the supplier’sinstructions. Care must be taken toensure screen weights are within thelifting capacity of the crane.
• LOLER regulations apply during all liftingoperations.
• User at all times must follow supplier’smethod statement for the safe use ofthe system.
Freestanding systemsFreestanding systems are typically used inflat roof applications or where theinclination is no greater than 10 degreesand there is reluctance to drill into thefabric of the roof. These systems can alsobe used to protect voids, lift shafts andstairwells, where it may be more difficultto support from elements of the buildingstructure.Where roofing membranes are being laid,facilities may exist for adapting systems toachieve clear unobstructed areas.
• When working at edge, the operativemust wear a suitable safety harnesswhich has been inspected and, in turn,should be anchored to a suitable point inthe structure in accordance with the safeuse of the restraining system.
• Estimate the material required andproduce a plan for the position of theguardrail together with any ballastpositions.
• Transport the material onto the roofsurface. This can be achieved by manuallifting, but can more effectively be doneby craning/ hoisting directly onto theroof.
• Point loads on the roof should beconsidered.
• At least two people will be required tobuild this type of system
• Lay out the equipment in approximatelythe right position. At this stage keepaway from the roof edge
• Connect the components together andmove towards the roof edge.
• The supplier should determine proximityto the edge permitted.
• Attach toeboards.
Mobile anchor and fixed anchorsystems Where it is not possible to confidentlyprevent a fall, it is a requirement of theWAH Regulations to mitigate theconsequences of a fall and this will requirethe use of a harness-based systemattached to a suitable anchor point. In theabsence of suitable support from thebuilding structure, a mobile anchor canoffer such support.
Whatever method is used, the BS 8437:2005 Code of Practice for selection, useand maintenance of personal fall protectionsystems should be referred to. Thisdocument covers restraint systems, rigidhorizontal/vertical anchor lines, workpositioning systems and other fall arrestequipment. The specification and hazardsof such systems are covered in detail. Itshould be read in conjunction with BS 7883.
BS 8437:2005, Code of Practice forselection, use and maintenance ofpersonal fall protection systemsand equipment for use in the workplace.
29
BS 7883:2005, Code of practice for thedesign, selection, installation, use andmaintenance of anchor devices conformingto BS EN 795.
Mobile anchor systems will generallycomprise a central framework with thefacility of attaching dedicated weightssufficient to resist the impact and weightof a person whilst falling. The frameworkwill feature a load-tested attachment pointfor an inertia/ fixed length/restraint fallarrest safety block. The line should berestricted in length for most applications toavoid the danger of any pendulum effect.
• The mobile anchor should have beentested to EN 795.
• It is important that all mobile anchorsystems are installed and used no closerthan 2 metres from the leading edge inorder to have sufficient clearance tooperate in the event of a fall.
• Check that the surface is capable ofbearing the deadweight of the anchor andthat the friction resistance is suitable.
• Do not use in icy or very wet conditions.• Assembled and used in accordance with
manufacturer’s instructions.• Many systems are designed to accept
only one person - check the capability.• Counterweights should be moved with
regard to manual handling requirements.• Employ internal lifts or mechanical
handling where possible.• The harness line should be of a
maximum length of 5 metres.• Attach counterweights to central
framework and check that all items aresecure.
• Clip karabiner hook to central eyebolt.
PerformanceSystems should be tested to BS EN 795Class B or E and should have the capabilityof resisting a dead force of 100kg droppingvertically through 2.5 metres. This shouldresult in a mass weight in the region of250 to 350kg for most systems.
ComponentsCentral anchor frameCounterweights Safety line and harness.
Tubular guardrail solutionsScaffold tube and fittings are the traditionalcomponents for constructing slab edgeprotection. Short length tubes are used forthe support posts, ties and bracingmembers, whilst tubes up to 6.4m inlength are used for the handrails. Thetubes are connected together by means offittings and the support posts shouldinclude a base plate. Toeboard is normally a3.9m scaffold board which should be fixedto the support post by means of atoeboard clip. Concrete blocks may berequired to stabilise this if used as afreestanding edge protection system.
Detailed guidance for the erection,alteration and dismantling of tubularscaffolding can be found in the NASCtechnical guidance document TG20:05. Thefollowing suggestions should be read inconjunction with that guidance:• When working at an edge, the operative
must wear a suitable safety harness andlanyard, which has been inspected and inturn, should be anchored to a suitablepoint in the structure in accordance withthe safe use of the restraining system.
• Tubular guardrail solutions should only bedesigned and installed by competent andsuitably experienced persons.
• Steel tubes should be cut square andclean, free from bends, distortion, splitsor corrosion and capped, where possible,to prevent injury to personnel or thegeneral public.
• All fixings should be made to appropriatestructure capable of sustaining the forcesrequired.
• All tubes should be connected with load-bearing couplers.
• Scaffold fittings should be tested to BS1139 or EN 74.
• Sleeve couplers should be used forhorizontal tubing.
• Maximum spacing for supporting poststo be set to achieve the performancerequirements for the relevant class ofprotection within EN 13374.
• Scaffold boards should comply with BS2482 and should not be warped, twisted,split or badly worn.
• Where loose materials are likely to bestacked or placed at a level above thetoeboard, brickguards or similarprotection may also be required.
30
Dismantling of edge protectionsystems
Sequence of Work• Ensure adequate knowledge of the
system has been gained prior to anydismantling operations and implementcontrols appropriate with the WAHlegislation.
• Edge protection systems must not beremoved prior to installation ofpermanent means of protection andwithout the explicit permission of themain contractor.
• Prior to any manual handling activity,consideration should be given toidentifying each component weight.
• Early consideration should be given tothe possible restricted access for plantand machinery necessary for thedismantling operation.
• Ground conditions should be made safeand suitable for any machinery tooperate.
• The dismantling procedures andsequence should be in line with thesupplier’s recommendations.
• The intention should be stated, e.g. “ thepurpose will be to dismantle thetemporary guardrail at the eaves positionand… guardrail at the gable position ofthe steel framed structure.”
• The grid line start point is to bedetermined on site prior to dismantling.
Use of MEWP’s• Once areas have been identified,
operatives will take possession of theboom lift and ensure it is in goodworking order.
• For safe use of MEWP’s refer to page 27• Use all appropriate PPE.• Full body harness with short fall arrest
harness (also known as restraint lanyard)to be clipped onto safe anchorage pointwhilst the MEWP is being operated.
• When removing edge protection fromMEWP’s or man-riding cradles, operatorsmust take note of component weightsand SWL of mechanical equipment.
• All measures should be taken to ensurehand tools or accessories are fit forpurpose and secured to working platformor the operator.
• Consideration should be given toprecluding the need for operatives toreach out of MEWP’s.
Movement of edge protectionequipment• When manually handling tubes,
operatives are to be aware of otheroperatives accessing around site andequally when manoeuvrings MEWP withtubes loaded. They are also to be awareof any operatives that may move into theerection area and will stop workimmediately until the area is cleared.
• Ensure edge protection components areneatly and safely stored in readiness forsite removal.
Dismantling of bolted edge protectionon steel framed buildingsConsideration should be given at earlyplanning stage to the issue of removal atan advanced stage of construction.Components can otherwise become lessaccessible. If components do becomelocked into less accessible positions it maybecome necessary to use accessplatforms for removal of presentundesirable risks of working at height.
31
Listed below are the major pieces ofhealth and safety legislation that apply tothe use of edge protection systems:
The Work at Height Regulations 2005
The Health and Safety at Work Etc Act1974 (HSWA)
The Management of Health and Safety atWork Regulations (MHSWR)
The Lifting Operations and LiftingEquipment Regulations (LOLER)
The Provision and Use of WorkEquipment Regulations (PUWER)
The Manual Handling OperationsRegulations
The Construction (Design andManagement) Regulations 2007 (CDM)
Construction Health and Safety at WorkRegulations ( modified by WAHregulations)
A guide to the safe transportation offormwork and falsework equipment
Hierarchy of hazardmanagement
All edge protection activities, in commonwith most other construction activities,should only be undertaken when using asafe system of work. A safe system ofwork is a formal procedure that resultsfrom a systematic examination of a task toidentify all of the hazards and assess theconsequent risks. It is a means of ensuringthat wherever possible hazards areeliminated or otherwise minimised by theapplication of appropriate controlmeasures.
It has been estimated that at least aquarter of all accidents at work involvefailures in systems of work. Therefore, it isessential that the entire process of edgeprotection erection and dismantling,including all peripheral activities, such asstorage and material handling, is coveredby a comprehensive safe system of work.
Hazard identificationIn the development of safe systems ofwork, the decision process should aim toidentify all hazards associated with theplanned activity and, if they cannot beeliminated, identify ways in which they canbe effectively controlled to an acceptablelevel of risk.
Significant hazards relating to edgeprotection include:
• Falls from height• Lifting & lowering of loads• Manual handling• Trapping• Inadequate working space• Structural instability• Inadequate access to height• Plant and machinery
32
10. Safety requirements
One of the most common hazardsencountered whilst installing edgeprotection on formwork decks is that ofworking at height, with falls from heightalone accounting for over 45% of all sitefatalities. In accordance with the Work atHeight Regulations, wherever reasonablypracticable, work at height should beavoided.
Risk assessments should be commencedat planning/design stage and be refinedthroughout the scheme and detaileddesign process. It is at concept stage thatdesigners can be most effective ineliminating or reducing hazards. This isbecause, as the design progresses,hazards get locked into the design andbecome harder to design out.
Hazards which cannot be avoided must becontrolled. The HSE promotes a structuredapproach to risk control which it refers to
Excessive gaps
Inadequate support
Edge protection too low
Inadequate support
Wrong orientation
Too close to the edge
33
Typical hazards
as a ‘hierarchical system’. The aim is topromote control measures on the basis of‘most effective first’. It is based on theclear principles that:
Prevention is better than protection.
Collective passive protection (protecting allpersonnel and not requiring actions by theindividual) is better than active personalprotection (requiring individual action).
As a last resort, care must be taken tomitigate the consequences of any accident.
Hierarchy of control measuresThis is expanded in the Management ofHealth and Safety at Work Regulations1999 as follows:
(a) Avoid risks.
(b) Evaluate the risks that cannot beavoided.
(c) Combat the risks at source.(d) Adopt the work to the individual.(e) Adapt to technological progress.(f) Replace the dangerous by the non or
less dangerous.(g) Develop a coherent overall prevention
policy.(h) Give collective protective measures
priority over individual protectivemeasures.
(I) Give appropriate instructions toemployees.
This is presented within the followingmatrix showing four levels of controlmeasure/equipment associated with workat height. At every level, collectivemeasures should be considered ahead ofpersonal ones.
34
Type of work equipmentCollective ProtectionMeasures
Work restraint systemsSingle user MEWPsFall factor 0
Work equipment thatminimises height andconsequences of fall
Nets at high levelSoft landing systems(close under work surface)
Personal fall protectionequipmentFall factor 1Fall factor 2
Work equipment thatminimises consequences offall
Soft landing systemsNets at low level(<6m below surface)
Life jacketsInflating air suitsInjury reduction systems
Work equipment that doesneither Hop-ups; platforms Ladders; step-ladders
Fig 1.0 Hierarchy of control measuresNote - In all cases collective protection measures have priority over personal protection measures
Leas
t ef
fect
ive
Mo
st e
ffec
tive
Regulations summary
The Work at Height RegulationsThese recently enacted regulations havebeen made to prevent deaths and injuriescaused by falls from work at height. Theyconsolidate and replace all earlierregulations about working at height. Theoverriding principle is that everythingreasonably practicable should be done toprevent anyone from being injured byfalling from height.
The regulations require duty holders toensure that:
• All work at height is properly planned andorganised.
• Those involved in work at height aretrained and competent.
• Any person involved in work at height,including organisation, planning,purchasing, shall be competent.
• The risks from work at height areassessed and appropriate workequipment is selected and used.
• The risks from fragile surfaces areproperly controlled.
• Equipment for work at height is properlyinspected and maintained.
Duty holders include employers, the selfemployed and anyone who controls theway work at height is undertaken.
The Health and Safety of Work Act 1974(HSWA)This act is the major piece of health andsafety legislation in Great Britain. It appliesto every type of work situation. The actsets out general duties for the health andsafety of those involved in work, includingemployers, employees, the self employed,suppliers of work equipment and thosewho control work premises. Section 6covers the requirement to provideadequate information.
The main general duties are contained insections 2 -7 of the act. Section 15provides the Secretary of State withextensive powers to make delegatedlegislation which contain more specificresponsibilities (e.g. The Management ofHealth and Safety at Work Regulations :
The Management of Health and Safetyat Work Regulations (MHSWR)The regulations place broad general dutieson employers and employees in all nondomestic work activities. They aim toimprove health and safety managementand make more explicit what is required ofemployers under the HSWA. Theregulations, which aim to encourage asystematic and organised approach tohealth and safety, overlap with severalother regulations such as the CDMRegulations (see below).
The broad requirements of the MHSWR onemployers are:
• To undertake an assessment of the risksto health and safety of their employeesand to other persons affected by theirundertaking.
• To make appropriate arrangements forimplementing any preventive orprotective measures identified in the riskassessment.
• To undertake health surveillance asappropriate regarding the risks toemployee’s health and safety identified inthe assessment.
• To appoint one or more competentpersons to assist in undertaking theabove measures.
• To provide relevant information to theiremployees.
The Lifting Operations and LiftingEquipment Regulations (LOLER)The regulations aim to reduce risks topeople’s health and safety from liftingequipment provided for use at work.
The regulations require that liftingequipment provided for use at work is:
• strong and stable enough for theparticular use and marked to indicatesafe working loads.
• positioned and installed to minimise anyrisks,
• used safely, i.e. the work is planned,organised and performed by competentpeople and,
• subject to ongoing thorough examinationand where appropriate, inspection bycompetent people.
35
Lifting equipment includes any equipmentused at work for lifting and lowering loadsincluding lifting accessories.
The Provision and Use of WorkEquipment Regulations (PUWER)Under these regulations work equipment,which includes machinery, appliances,apparatus, tools, component assembliesand in some cases, complete plant, must:
• be suitable for its intended task and areaof operation,
• be well maintained and• conform to certain EC requirements.
When work equipment poses a specificrisk, only designated, trained persons mayuse or maintain it. Employees mustreceive adequate information, instructionand training on how to safely use theequipment. They must also understandthe risks and necessary control measuresassociated with their work.
The Manual Handing OperationsRegulationsThe Regulations, aimed at reducing the riskof injury from manual handling, establish ahierarchy of measures to be followed:
• Avoid hazardous manual handlingoperations so far as is reasonablypracticable. This may be done byredesigning the task to avoid moving theload or by automating or mechanising theprocess.
• Make a suitable and sufficientassessment of any hazardous manualhandling operations that cannot beavoided.
• Reduce the risk of injury from thoseoperations so far as is reasonablypracticable. Where possible, mechanicalassistance should be provided, forexample, a trolley or hoist. Where this isnot reasonably practicable then changesto the task, the load and the workingenvironment should be explored.
The assessment referred to above shouldconsider:
• The load to be manually lifted.• The task i.e. twisting bending etc.• The environment where the activity is
being carried out.
Employers must provide employees withinformation about the nature of the load tobe lifted and employees should make fulluse of any work equipment provided bythe employer.
The Construction (Design andManagement) Regulations 2007 (CDM2007)The construction industry covers a widerange of activities, hazards, materials,techniques employment patterns andcontractual arrangements. The regulationsare based on the premise that goodmanagement of construction progressfrom concept through to completion isessential if health and safety standards areto improve.
The regulations require the systematichealth and safety management of projects.Hazards must be identified and eliminatedwhere possible, and the remaining risksreduced and controlled. This approachreduces risks during construction work andthroughout the life cycle of a structure(including eventual demolition).
In summary, the regulations require:
• a realistic project programme withadequate time allowed for planning,preparation and the work itself;
• early appointment of key people:Competent duty holders with sufficientresources to meet their legal duties;
• provision of health and safety informationfrom the start of the design phase,through construction and maintenance toeventual demolition, so that everyonecan discharge their duties effectively;
• co-operation between duty holders andeffort and resources proportionate to therisk and complexity of the project to beapplied to managing health and safetyissues.
