1 temporary works temporary works 2 temporary works definition definition (according to bsi)...

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Temporary WorksTemporary Works

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DefinitionDefinition (according to BSI)(according to BSI) Any temporary construction necessary to Any temporary construction necessary to

assist the execution of the permanent works assist the execution of the permanent works and which will be removed (sometimes not) and which will be removed (sometimes not) from the site on completion.from the site on completion.

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((according to theaccording to the General Conditions of General Conditions of Contract for Civil Engineering Works, Contract for Civil Engineering Works, Hong Kong Government 1993 Edition)Hong Kong Government 1993 Edition)

All temporary work of every kind required All temporary work of every kind required for the construction, completion and for the construction, completion and maintenance of the Works.maintenance of the Works.

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Common Temporary Works in Common Temporary Works in construction sitesconstruction sites

Hoading & Fencing, Site offices, storage Hoading & Fencing, Site offices, storage facilitiesfacilities

Excavation supportsExcavation supports Access ScaffoldsAccess Scaffolds Working PlatformsWorking Platforms

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Common Temporary Works in Common Temporary Works in construction sitesconstruction sites

FalseworkFalsework ShoringShoring Temporary Access Bridges, RampTemporary Access Bridges, Ramp Temporary Structures for Construction PlantsTemporary Structures for Construction Plants River Diversion StructuresRiver Diversion Structures

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Temporary Works and the Temporary Works and the Conditions of ContractConditions of Contract

General Conditions of Contract for Civil General Conditions of Contract for Civil Engineering Works, Hong Kong Engineering Works, Hong Kong Government 1993 EditionGovernment 1993 Edition

Clause 10 Clause 10 –– Extent of Contract ( General Extent of Contract ( General ObligationsObligations ) )

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Temporary Works and the Conditions Temporary Works and the Conditions of Contractof Contract

The Contractor shall, subject to the provisions The Contractor shall, subject to the provisions of the Contract, execute the Works and provide of the Contract, execute the Works and provide all labor, materials, Construction Plant, all labor, materials, Construction Plant, Temporary Works, transport to and from the Temporary Works, transport to and from the Site or in and about the Works and everything Site or in and about the Works and everything whether of a temporary or permanent nature whether of a temporary or permanent nature required in and for such execution so far as required in and for such execution so far as necessary for providing the same is specified in necessary for providing the same is specified in or reasonably to be inferred from the Contractor reasonably to be inferred from the Contract

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Temporary Works & the Common Temporary Works & the Common LawLaw

It shall be the duty of any person who It shall be the duty of any person who designs, manufactures, imports or designs, manufactures, imports or supplies any article for use at work,supplies any article for use at work,

(a)(a) to ensure, so far as is reasonably to ensure, so far as is reasonably practicable, that the article is so designed practicable, that the article is so designed and constructed as and constructed as to be safe and to be safe and without risks to healthwithout risks to health when properly when properly used;used;

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(b) to carry out or arrange for the carrying (b) to carry out or arrange for the carrying out of such out of such testing and examinationtesting and examination as as may be necessary for the performance of may be necessary for the performance of the duty imposed upon him by the above the duty imposed upon him by the above paragraph;paragraph;

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(c) to take such steps as are necessary to (c) to take such steps as are necessary to securesecure that there will be available in that there will be available in connection with the use of the article at work connection with the use of the article at work necessary and adequate informationnecessary and adequate information about about the use for which it is designed and has been the use for which it is designed and has been tested, and about any conditions necessary to tested, and about any conditions necessary to ensure that when put to that use, it will be safe ensure that when put to that use, it will be safe and without risks to health.and without risks to health.

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Temporary Works & Contract PricingTemporary Works & Contract Pricing

Requirements of temporary works: labor, Requirements of temporary works: labor, plants, materials, construction plants, materials, construction methods(including safety provisions) and methods(including safety provisions) and the associated cost need to be established the associated cost need to be established at the tender stage.at the tender stage.

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Temporary Works & Contract PricingTemporary Works & Contract Pricing

Otherwise the tender sum may not allow Otherwise the tender sum may not allow sufficient budget for the subsequent site sufficient budget for the subsequent site activities in the construction phase, hence activities in the construction phase, hence decreasing the Contractor's profit margin decreasing the Contractor's profit margin or to the worst incurring a significant loss or to the worst incurring a significant loss at the end of the Contractat the end of the Contract

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DESIGN OF TEMPORARY WORKSDESIGN OF TEMPORARY WORKS

Standard SolutionsStandard Solutions Solutions to temporary works problem by Solutions to temporary works problem by

reference to tables/charts previously reference to tables/charts previously prepared for the likely variety of loadings prepared for the likely variety of loadings that could be met in situations amenable that could be met in situations amenable to their use. to their use.

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DESIGN OF TEMPORARY DESIGN OF TEMPORARY WORKSWORKS

Relevant information could be available from :Relevant information could be available from : I. in-house tabulations showing loads and I. in-house tabulations showing loads and

spacing of materials used on a standardized spacing of materials used on a standardized basis;basis;

II. authoritative guidance documents resulting II. authoritative guidance documents resulting from research and testing e.g. CIRIA Reports, from research and testing e.g. CIRIA Reports, B.S. B.S.

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DESIGN OF TEMPORARY WORKSDESIGN OF TEMPORARY WORKS

III. documents provided by III. documents provided by manufacturers marketing proprietary manufacturers marketing proprietary equipment tested to comply with the equipment tested to comply with the relevant local legislation/industrialrelevant local legislation/industrial standards.standards.

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Why Standard Solutions ?Why Standard Solutions ?

Requirements in relation to temporary works can Requirements in relation to temporary works can

be assessed with good accuracy.be assessed with good accuracy. The pricing of various bill items will be more The pricing of various bill items will be more

accurate.accurate. Standard solution tables provide site management Standard solution tables provide site management

with the means of checking the work of with the means of checking the work of subcontractors involved in carrying out the subcontractors involved in carrying out the temporary works on site.temporary works on site.

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Designed SolutionsDesigned Solutions

Designed solutions become necessary for Designed solutions become necessary for

situations where the standard solutions are in situations where the standard solutions are in appropriate. Competent persons should be appropriate. Competent persons should be employed in such particular site situations.employed in such particular site situations.

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SCAFFOLDING SCAFFOLDING

DefinitionDefinition:: a crucial item to ensure that workers have a safe a crucial item to ensure that workers have a safe

place of work and a safe means of access to it.place of work and a safe means of access to it.

Related legislationRelated legislation:: Strength and Stability; Platform widths for Strength and Stability; Platform widths for

various purposes; Provision of hand rails, toe various purposes; Provision of hand rails, toe boards, prevention of materials falling off boards, prevention of materials falling off scaffoldsscaffolds

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SCAFFOLDINGSCAFFOLDING

Codes of Practice:Codes of Practice:

BS 5973:1990 Code of Practice of BS 5973:1990 Code of Practice of scaffoldingscaffolding (design code) (design code)

BS 1139:1981 Part 3 Specification for BS 1139:1981 Part 3 Specification for prefabricated access and worker towersprefabricated access and worker towers

No codes of practice for proprietary systemsNo codes of practice for proprietary systems

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Terminology in Scaffolding LayoutTerminology in Scaffolding Layout

StandardsStandards LiftLift BayBay Ledger/LacingLedger/Lacing Diagonal BraceDiagonal Brace Ledger BraceLedger Brace Plan BracePlan Brace TransomTransom

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PutlogPutlog CouplerCoupler GuardrailGuardrail Decking/BoardingDecking/Boarding ToeboardToeboard Sole Plate/BoardSole Plate/Board

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U-head/Fork headU-head/Fork head Screw (U-head/Base)JackScrew (U-head/Base)Jack Prop (telescopic)Prop (telescopic) Tie rodTie rod

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Couplers & Fittings Couplers & Fittings

Standard 90 deg Standard 90 deg couplercoupler

Fixed couplerFixed coupler Swivel couplerSwivel coupler Safety/Check Safety/Check

couplercoupler

Putlog headPutlog head Reveal pinReveal pin

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Types / Configurations of ScaffoldsTypes / Configurations of Scaffolds A. A. Tube and Fitting ScaffoldsTube and Fitting Scaffolds Putlog Scaffolds :Putlog Scaffolds : scaffolds are those which have one line of scaffolds are those which have one line of

standards to support the outside of the scaffold standards to support the outside of the scaffold deck, while the inside edge is supported from the deck, while the inside edge is supported from the wall being built. The 'putlog' is a transom wall being built. The 'putlog' is a transom member with a flattened end to rest on masonry member with a flattened end to rest on masonry walling. The whole scaffold erection is slightly walling. The whole scaffold erection is slightly lean inwards to increase stability.lean inwards to increase stability.

Limitation - for use on load bearing walls only.Limitation - for use on load bearing walls only.

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Types / Configurations of ScaffoldsTypes / Configurations of Scaffolds

Independent Tied ScaffoldsIndependent Tied Scaffolds : : scaffolds are those have two rows of standards scaffolds are those have two rows of standards

supporting the working deck. The transom supporting the working deck. The transom members are tied between the two layers of members are tied between the two layers of standards and act independent of what is being standards and act independent of what is being built. For improving the overall scaffold built. For improving the overall scaffold stability, the structure is tied at some points to stability, the structure is tied at some points to the new building.the new building.

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Special Scaffolds for specialised workSpecial Scaffolds for specialised work Free-standing scaffoldsFree-standing scaffolds - movable and stable Vs - movable and stable Vs

overturning without any attachment to any other overturning without any attachment to any other structure but occasional guy or raking strut structure but occasional guy or raking strut support. (Covered by BS 1139 : Part 3. 1983)support. (Covered by BS 1139 : Part 3. 1983)

Slung ScaffoldSlung Scaffold - those hanging from a structure - those hanging from a structure overhead but incapable of being moved sideways overhead but incapable of being moved sideways or raised or lowered. (Covered by 5973:1990)or raised or lowered. (Covered by 5973:1990)

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Suspended ScaffoldsSuspended Scaffolds - working - working platforms suspended on wire ropes from a platforms suspended on wire ropes from a suitable structure above, such that they suitable structure above, such that they can be raised or lowered, but not moved can be raised or lowered, but not moved sideways. (Covered by 5974:1982)sideways. (Covered by 5974:1982)

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B. Proprietary Scaffolding SystemsB. Proprietary Scaffolding Systems The specialised systems are designed to The specialised systems are designed to

avoid the use of loose fittings and are modular avoid the use of loose fittings and are modular in concept. Their load carrying capacity and in concept. Their load carrying capacity and structural stability work on a deem-to-satisfy structural stability work on a deem-to-satisfy basis after extensive testing to validate the basis after extensive testing to validate the performance figures by the respective performance figures by the respective manufacturers.manufacturers.

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Comparison between Tube & Fittings Comparison between Tube & Fittings

Scaffold and Proprietary ScaffoldScaffold and Proprietary Scaffold

Tube and Fitting ScaffoldTube and Fitting Scaffold AdvantageAdvantage more flexible to awkward situations and more flexible to awkward situations and

dimensions which do not fit the modules of dimensions which do not fit the modules of proprietary methods.proprietary methods.

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Comparison between Tube & Fittings Comparison between Tube & Fittings Scaffold and Proprietary ScaffoldScaffold and Proprietary Scaffold

Proprietary ScaffoldProprietary Scaffold AdvantagesAdvantages:: Connection methods provide a rigid Connection methods provide a rigid

connection to standards than conventional tube connection to standards than conventional tube and fittingsand fittings

The members are of fixed modules and hence The members are of fixed modules and hence the scaffold set out itself. If dimensions are the scaffold set out itself. If dimensions are wrong, the pieces will not fit together.wrong, the pieces will not fit together.

It is easier and quicker to train scaffolders.It is easier and quicker to train scaffolders.

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Proprietary ScaffoldProprietary Scaffold Advantages (ContAdvantages (Cont’’d)d):: Few loose fittings are needed.Few loose fittings are needed. Quicker erection due to no coupling to be Quicker erection due to no coupling to be

set out or done up required in the tube set out or done up required in the tube methods.methods.

Losses are minimized because of the size of Losses are minimized because of the size of the standard components.the standard components.

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Proprietary ScaffoldProprietary Scaffold Disadvantage:Disadvantage: the capital cost is grater than with the capital cost is grater than with

tube and fittings.tube and fittings.

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Division between standard and Division between standard and designed solutionsdesigned solutions

BS 5973 recommends that the design of BS 5973 recommends that the design of Tube & Tube & Fitting ScaffoldsFitting Scaffolds can adopt standard solutions (i.e. can adopt standard solutions (i.e. without design calculation) up to 50 metres high without design calculation) up to 50 metres high provided that they do not carry loads nor greater bay provided that they do not carry loads nor greater bay lengths than those specified in the document, nor lengths than those specified in the document, nor subjected to loading of materials by mechanical subjected to loading of materials by mechanical means.means.

The The Proprietary Scaffold SystemsProprietary Scaffold Systems all come into the all come into the standard solutions. Any modified approach need to be standard solutions. Any modified approach need to be supported by designed solutions. supported by designed solutions.

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Checklist for scaffolding Checklist for scaffolding requirementsrequirements

Preparations for scaffolding specifications will Preparations for scaffolding specifications will be assisted by having available a checklist be assisted by having available a checklist similar to one shown below of all possible similar to one shown below of all possible types of scaffolding that may be needed for types of scaffolding that may be needed for both internal and external construction both internal and external construction activities.activities.

1. External elevations1. External elevations 2. Scaffold to roof level structures2. Scaffold to roof level structures 3. Hoist towers3. Hoist towers

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4. Rubbish chutes4. Rubbish chutes 5. Loading towers5. Loading towers 6. Internal wall and partition scaffold6. Internal wall and partition scaffold 7. Birdcage access scaffold7. Birdcage access scaffold 8. Mobile access towers8. Mobile access towers

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9. Truss-out Access scaffold 10.Handrails and guardrails 10.Handrails and guardrails 11. Lift shafts11. Lift shafts 12. Protective fans12. Protective fans 13. Other specialist requirements13. Other specialist requirements 14. Protection requirements14. Protection requirements

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Provisions in Scaffolding ContractsProvisions in Scaffolding Contracts ResponsibilitiesResponsibilities 1. The scaffold owner shall declare the loads that are 1. The scaffold owner shall declare the loads that are

brought down by each standard. The hirer will be brought down by each standard. The hirer will be responsible for adequate foundations and this responsible for adequate foundations and this information on loading of standards is necessary for information on loading of standards is necessary for him to provide the necessary support.him to provide the necessary support.

2. The hirer is responsible for the provision of 2. The hirer is responsible for the provision of sufficient anchorage points for a positive tie into the sufficient anchorage points for a positive tie into the structure, in accordance with BS 5973 or as may be structure, in accordance with BS 5973 or as may be agreed between the parties.agreed between the parties.

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Provisions in Scaffolding ContractsProvisions in Scaffolding Contracts

3. Those erecting the scaffold will ensure that the 3. Those erecting the scaffold will ensure that the scaffolding is soundly and adequately constructed scaffolding is soundly and adequately constructed and complies with appropriate Regulations (esp. in and complies with appropriate Regulations (esp. in respect of safety) on handing over.respect of safety) on handing over.

4. The legal requirements calling for regular 4. The legal requirements calling for regular inspections of the scaffold thereafter rest with site inspections of the scaffold thereafter rest with site management.management.

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Provisions in Scaffolding ContractsProvisions in Scaffolding Contracts

PricingPricing 1. Provision of scaffolding as described by the 1. Provision of scaffolding as described by the

main or specialist contractor who is responsible main or specialist contractor who is responsible for its provision;for its provision;

2. The extra over rate for the hire of the scaffold 2. The extra over rate for the hire of the scaffold if the contract period is overrun, as a rate per if the contract period is overrun, as a rate per week;week;

3. Hourly labor rates for alterations to the 3. Hourly labor rates for alterations to the scaffold after the initial erection. scaffold after the initial erection.

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Site Safety RegulationsSite Safety Regulationsfor Scaffolding Worksfor Scaffolding Works

The responsibilities of a contractor in working The responsibilities of a contractor in working with scaffolds under the Construction Sites with scaffolds under the Construction Sites (Safety) Regulations of Hong Kong are :(Safety) Regulations of Hong Kong are :

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(I) ensure practicable, suitable and sufficient safe (I) ensure practicable, suitable and sufficient safe access to and egress from every place on site at which access to and egress from every place on site at which any person at any time works, and maintain it any person at any time works, and maintain it properly,properly,

(ii)(ii) ensure every place on the site shall be made ensure every place on the site shall be made and kept safe for any person working there and kept safe for any person working there

(iii)(iii) ensure that no scaffold is erected on the site or ensure that no scaffold is erected on the site or substantially added/altered/dismantled except under substantially added/altered/dismantled except under the immediate supervision of a competent person and the immediate supervision of a competent person and by competent workmen of adequate and appropriate by competent workmen of adequate and appropriate working experience.working experience.

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(iv)(iv) ensure every scaffold is of good construction, ensure every scaffold is of good construction, made of strong and sound materials and free from made of strong and sound materials and free from patent defect and properly maintained.patent defect and properly maintained.

(v)(v) ensure every scaffold is kept so fixed, secured ensure every scaffold is kept so fixed, secured

or placed in position.or placed in position. (vi)(vi) no part of structure or building is used in no part of structure or building is used in

support for a scaffold unless it is strong and stable.support for a scaffold unless it is strong and stable.

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(vii) the scaffolds to be inspected by a (vii) the scaffolds to be inspected by a competent person within the immediately competent person within the immediately preceding month,preceding month,

(viii) inspection reports to be made in (viii) inspection reports to be made in

approved forms by the person who is approved forms by the person who is responsible for inspection which contain the responsible for inspection which contain the prescribed particulars and delivered to the prescribed particulars and delivered to the contractor concerned.contractor concerned.

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Bamboo Scaffolds - AdvantagesBamboo Scaffolds - Advantages

FlexibilityFlexibility Bamboo could be cut and lapped through fastening thus Bamboo could be cut and lapped through fastening thus

tailor-assembled easily to suit the profile and contour for tailor-assembled easily to suit the profile and contour for most construction structures even of very complicated most construction structures even of very complicated geometry and shape.geometry and shape.

Bamboo scaffolds could also be erected at any elevation Bamboo scaffolds could also be erected at any elevation of a multi-storey building, for instance truss-out scaffold of a multi-storey building, for instance truss-out scaffold structures, which is particularly advantageous in Hong structures, which is particularly advantageous in Hong Kong where tall buildings are crowded with limited space Kong where tall buildings are crowded with limited space for access in general.for access in general.

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Bamboo when combining with steel brackets Bamboo when combining with steel brackets as the primary structural supports could be a as the primary structural supports could be a very safe solution for most scaffolding work.very safe solution for most scaffolding work.

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Cost effectivenessCost effectiveness

· · Abundant supply of bamboo is available from the Abundant supply of bamboo is available from the Southern China areas, thus reducing the cost of Southern China areas, thus reducing the cost of transportation for scaffolding work in Hong Kong.transportation for scaffolding work in Hong Kong.

· · Fast growth in bamboo plantation could make it as a Fast growth in bamboo plantation could make it as a cheap and environmental friendly temporary works cheap and environmental friendly temporary works materialsmaterials

The cost is usually a few percent of that of steel The cost is usually a few percent of that of steel scaffolding tubes.scaffolding tubes.

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SpeedinessSpeediness

· · Bamboo is very light-weighted which can be Bamboo is very light-weighted which can be handled by workers and it requires no handled by workers and it requires no machinery and sophisticated hand tools.machinery and sophisticated hand tools.

This feature is leading bamboo scaffolds could This feature is leading bamboo scaffolds could be erected and dismantled much faster than be erected and dismantled much faster than other types of other types of scaffolding.other types of other types of scaffolding.

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Bamboo Scaffolds Bamboo Scaffolds - Common Causes of Failure & - Common Causes of Failure &

LimitationsLimitations

1.1. A safely erected bamboo scaffold could be put A safely erected bamboo scaffold could be put into a dangerous access structure for into a dangerous access structure for construction workers if other trade-workers construction workers if other trade-workers damage it through cutting bamboo elements to damage it through cutting bamboo elements to suit their own operational needs e.g. plastering suit their own operational needs e.g. plastering work, plumbing.. etc.work, plumbing.. etc.

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Bamboo Scaffolds Bamboo Scaffolds - Common Causes of Failure & Limitations- Common Causes of Failure & Limitations

2.2. Immature bamboo was imported and used for Immature bamboo was imported and used for the scaffolding work, in particular when there the scaffolding work, in particular when there is a large over-consumption of bamboo in the is a large over-consumption of bamboo in the times when construction is a blooming times when construction is a blooming business.business.

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3.3. Inadequate of monitoring and Inadequate of monitoring and maintenance of bamboo scaffold erected maintenance of bamboo scaffold erected are not uncommon in local building sites. are not uncommon in local building sites. Sometimes a bamboo scaffold is left Sometimes a bamboo scaffold is left unattended for several months.unattended for several months.

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4.4. Unskilled scaffolding workers are employed Unskilled scaffolding workers are employed to erect or dismantle bamboo scaffold. to erect or dismantle bamboo scaffold. Traditional skill and correct code of practice Traditional skill and correct code of practice are neither ignored nor carried out by are neither ignored nor carried out by inexperienced workers which eventually inexperienced workers which eventually produce an unsafe temporary structure.produce an unsafe temporary structure.

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5.5. Bamboo is a natural material bearing Bamboo is a natural material bearing biological defects which are difficult to be biological defects which are difficult to be characterised assessment in the current characterised assessment in the current engineering practices. Design and engineering practices. Design and construction of bamboo scaffolds depends on construction of bamboo scaffolds depends on skill and experience of the trade. Application skill and experience of the trade. Application to very high-rise and heavy duty structural to very high-rise and heavy duty structural works should be avoided.works should be avoided.

1 temporary works temporary works 2 temporary works definition definition (according to bsi)...

Documents

common temporary works

permanent works

civil engineering works

ramp temporary structures

ramp temporary access

hong kong government

site offices

edition clause