GL 17 Scaffolding

7/29/2019 GL 17 Scaffolding

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Rev. 02 Dec 2012 Page 1 of 18

Guideline No: CS-GL-17 Issue Date: 31/12/2012

Title: Scaffold Guidelines

Issued By: Facility Permit Section

1.0 Introduction

Frameworks and Platforms, erected on iron poles, bamboos and other rigidmaterials are a common sight around buildings, bridges and similar structures thatare under construction or repair. The main aim of these structures is to providesafety to man & material from falling.

Scaffold is an elevated platform work which is temporary is nature. There are anumber of structural elements integrated in the scaffold project for protectingworkers against falls. Walkways, Personal fall arrest system, erection &maintenance of scaffolds as well as Training of workers are the main elements of ascaffold system.

The purpose of a working scaffold is to provide a safe working place & safe accesssuitable for the work being done. Most work related injuries happen when workersare working above a height of 1.5 - 2 meters. It is therefore imperative to usescaffolding which are designed and erected properly. Failure to understand andcomply with all applicable safety requirements, regulations and these safetyguidelines before installing, using or dismantling scaffolding can result in seriousinjury or death. This guideline is to prevent accidents at the workplace.


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2.0 Scope: -

This guideline is to promote safe erection of Scaffold which is used in theConstruction industry in areas within the jurisdiction of Dubai world. Thisguideline defines, identifies and describes safe methods of scaffold erection whichcan create awareness of hazards associated with the use of scaffold during erection& utilization. This guideline also specifies the criteria to be observed in the design& construction of a scaffold.

3.0 General Requirements:-

Inspect entire job site to determine ground conditions, strength of supportingstructure, the proximity with electric power lines, overhead obstructions, windconditions and the need for overhead protection or weather protection coverings

The contractor must prepare the construction design, drawing & design loads for allthe scaffold used on site and must be approved by a consultant. This documentmust be readily available at site.

The maximum height of the scaffold shall not exceed 10 meters and in case theneed for higher scaffold arises the contractor shall appoint a 3rd Party for scaffolderection & supervision.

All equipments must be inspected to see that they are in good condition. Damagedor deteriorated equipment should be reported and replaced.

Wooden planks used for scaffolding must be inspected to ensure that they aresound and in good condition, straight grained, free from nails, saw cuts, splits andholes. (Not all species and grades of lumber can be used as scaffold plank.)

The following are the important aspects which need to be taken care of whileerection of scaffold:-

3.1 Scaffold Foundation:-

Base plates are mandatory even while setting on concrete floor or Soil (i.e. soilmust be compacted properlyThe base plate must be not be less than 5 cm thick and not less than 25 cm wide todistribute load evenly. (See figure # 01)


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Fig. 01

3.2 Scaffold Platform:-

The width of the platform shall not be less than 60 cm wide (3 boards)

The width of the platform shall not be less than 80 cm wide (4 boards) when bothperson & material are used.

The platform must be provided with standard guard rail (95 cm), which consists ofmid rail & top rail

The height of the toe board shall not be less than 15 cm. (see figure # 02)

Fig. 02


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3.3 Safe Access:-

Safe access must be provided for entrance and exit Ladders are commonly used to access the platforms Ladders must have slope 4:1 of height and shall extend 1 meter above the

platform level, for safe hold & landing on platform

Ladder must be secured properly on level surface. (See figure # 03)

Fig.03

4.0 General Guideline for Scaffold installation

Scaffold should be installed, moved, or disassembled only by and under thesupervision of competent persons.

Base plates must be of adequate size to distribute the loads on the scaffolding tothe soil or supporting structure.

DO NOT USE unstable objects such as blocks, loose bricks, etc. Ties, bracing and outriggers may be needed to ensure a safe stable scaffold

assembly. Scaffolding must always be secured when the height of the scaffold exceeds for 4

times the minimum base width.

Vertical ties should be placed at the ends of scaffold runs and at no more than 10meter horizontal intervals in between.


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Work platforms must be fully planked, either with scaffold graded solid sawn orlaminated plank or with fabricated platforms in good condition.

Loads on plank should be evenly distributed and should not exceed the allowableloads for the type of plank being used.

Planks and/or platforms should be secured to scaffolding when necessary toprevent uplift of displacement because of high winds or other job conditions.

Both top and mid rail guardrails are required and must be used on all open sidesand ends of scaffold platforms.

Access must be provided to all work platforms. If it is not available from thestructure, access ladders or frames with built-in ladders stairways must be

provided.

Side and end brackets are designed to support people only. Materials shouldnever be placed on cantilevered platforms unless the assembly has been

designed to support material loads by a qualified person

Scaffold cannot be erected or used, closer than 3 meters (10 feet) near anenergized power line, to avoid any contact between scaffold component and

power lines.

Check the installed scaffolding before you allow people to use it. A qualifiedperson must thoroughly inspect the completed assembly.

Tagging system must be followed properly during erection, dismantling and whenoperative is working on the scaffold


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5.0 Basic types of Scaffolds: -

Scaffolds can be classified in following categories :-

5.1 Supported Scaffolds: In this type of scaffold, one or more than one platforms aresupported with load bearing substances like legs, poles, outriggers, frames etc.Commonly used supported scaffold are Metal Scaffold, Tube & Clam Scaffold & FrameScaffold (see figure # 04)

5.1.1 Basic Requirement for Supported Scaffold:-

Metal part used for supported scaffold must be straight & free from all defects

All parts of the scaffold must be secured properly. Suitable access must be provided with ladder or stairways and must be attached

to scaffold structure.

All material used for the scaffold must be stored properly, to prevent them frombeing affected by weather conditions.

All material used for the scaffold must be inspected regularly and maintainedproperly.

Scaffolding erection must be carried out by a competent person under propersupervision.

Tagging system must be followed properly during erection, dismantling and whenoperative is working on the scaffold.

All of the suspended scaffold must be inspected and must have valid testcertificate issued by approved third party agency.

Fig.04


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5.2 System Scaffolds: - In this type of scaffold vertical pipe with different length

(post) and the runner and the bearer are connected with each other. The most popularone is the cup-lock system scaffold where all the blades of the pipes are located in thelower cup and the upper cup is lowered down & tightened with hammer blow (seefigure # 05)

5.2.1 Basic Requirement for System Scaffold:-

Metal part used for system scaffold must be straight & free from all defects All parts of the scaffold must be secured properly. Suitable access must be provided with ladder or stairways and must be attached

to scaffold structure.

All material used for the scaffold must be stored properly, to prevent them frombeing affected by weather conditions.

All material used for the scaffold must be inspected regularly and maintainedproperly.

Scaffolding erection must be carried out by a competent person under propersupervision.


Fig.05


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5.3 Suspended Scaffolds:

Suspended scaffold consist of platforms suspended by wires, ropes, fixed outrigger,which are installed horizontally on the roof of the building. Wherev suspended scaffoldshall be used, proper counter weights shall be attached on the other end of the outrigger to support the scaffold. There are many types of suspended scaffolds such assuspended platform, cradle scaffold & boatswains chairs. (See figure # 06).

5.3.1 Basic Requirement for Suspended Scaffold:-

All suspended scaffolds must be provided with suitable chain or ropes and winches and

shall be suspended for suitable outrigger, beams, joists, runways, rails.

The counter weight, when used with outriggers, must be securely fastened to the outriggers and must not be less than four times the total weight of the scaffold.

The operative working on suspended scaffold must use proper fall protection system(i.e. full body harness, lanyards, Shock absorber, rope grabbing device & life line).

No wire other than wire rope shall be used for raising & lowering & suspension of asuspended scaffold.

The space between the structure and the platform shall not be more than 30 cmAll suspended scaffold must be inspected and must have valid test certificate issued byapproved third party agency.



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Fig.06

5.4 Mobile Tower Scaffold: - A portable, wheel-mounted, caster scaffold, whetherun-powered or powered, is known as mobile scaffold. (See figure # 07)

5.4.1 Basic Requirement for Mobile Tower Scaffold:-

The height of the mobile towers shall not exceed 4 times the smallest base widthof the scaffold, in case the height is exceeding 4 times the width of the scaffold.

Rolling scaffolds shall be moved on levelled surfaces only by pushing or pulling orboth.

No persons, equipment or materials are allowed to be on the platform when it ismoved.

It is recommended to use a ladder (internal staircase) for access to and from theplatform (in case of using a vertical ladder higher than 6m, it shall be protected

by a cage or provide workers with proper fall protection equipment). Mobile scaffolds must be provided with caster wheels & locking brakes to prevent

unsteady movement.


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Fig.07

6.0 Hazards associated with scaffolding:-

Incidents of falling, owing to lack of proper fall protection system. Scaffolds may collapse, due to overloading or instability. Proximity of scaffolds to overhead power lines can increase the risk of

electrocution.

Scaffold may also collapse when struck by debris, tools and work materials. Falls from elevation, due to lack of fall protection

(See figure # 08)

Being struck by falling tools, work materials, or debris.


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Fig.08

6.0 Management, Risk reduction & Control of Scaffolding Hazards

6.1 Management of scaffolding activity:

During any construction activity there is high level of risk due to scaffolding work, andthis requires a proper safety management system to prevent any accident associatedwith scaffolds. The below five steps can provide a brief description of good safetymanagement system during scaffold operation (see figure # 09)

Fig.09


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All scaffolding dose not required a design. General access/Mobile scaffold scaffolding,erected in accordance with the manufacturers instructions, does not require anyfurther design. However, if a design is required then a competent scaffold designermust be engaged to design the scaffold. (See figure # 10)

Fig .10

The contractor should define a policy in relation to scaffolding. This written scaffoldingpolicy should:

Include a commitment to protect employees & other personnel working at site

Require to appoint competent person for erection maintenance & dismantling ofscaffold on site

Include a commitment to comply with relevant health and safety legislation, & LocalRegulation and relevant codes of practice and guidelines.

Developing a team for scaffold and assign responsibility for choosing the type ofscaffold according to design procedure


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Proper planning must be done during scaffold erection activity to minimize the riskinvolved

Scaffolding procedure and plan must be readily available on site with all the instructionfor assembly, use, dismantling or alteration of scaffold

The planning must contain contractor, Scaffolding Designer & scaffolding erector roles& responsibility. The planning process should highlight the following areas werepersonnel has to concentrate

Local and other Legal requirements must be followed Assigning of Roles and Responsibilities Hazards Identification and necessary precaution in the assigned task Assessment of Risk and must be eliminated or reduced Clear performance standards should be set Scaffold erection site survey

The written plan is transformed into action during the implementation stage. Successfulimplementation requires that the following issues be addressed.

Roles & Responsibilities in the assigned task Instruction, Training and proper supervisor for Contractor & Scaffold Erector All the relevant information related to design scheduling, loading must be

communicated to responsible persons All the Document (i.e. HSE Plan, Scaffold plan, Inspection record) related to

scaffold must be kept & maintained on site


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Regular inspection is a must to determine if performance standard Periodic checking isnecessary to determine if performance standards are meeting with local and other legalrequirements, and to take necessary corrective action

Scaffolding must be inspected by a competent person

The review stage helps to make each job a learning experience so that the next job canbe performed more effectively. The following questions should be asked:

Was the planning adequate or were there unwelcome surprises? Was the implementation adequate so that the job was completed as planned? Were the planned checks carried out and did the necessary corrective action

take place?

What changes will be necessary for the next job?


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A more General Hierarchy of Hazards control is depicted below(see figure # 11)

HIERARCHY OF HAZARDS CONTROL

Fig.11

7.0 DOs& DONT s

7.1 Do

Make sure a competent person has inspected the scaffold before you go up. Wear a hard hat whether you work on or under a scaffold. Be sure to wear sturdy shoes with nonslip soles as well. Use a personal fall arrest system whenever required. Watch out for co-workers on the scaffold as well as people below. Always use common sense when working on any scaffold, and move around slowly

and carefully.

Ask a supervisor if you're not sure if a scaffold or working conditions are safe.


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7.2 DONT

Take chances.

Overload a scaffold. Keep debris or unnecessary materials on a scaffold where someone could trip

over them or accidentally knock them off the platform.

Hit a scaffold with anything heavya truck, a forklift, a load of lumber, etc. Leave materials and equipment on the platform at the end of the day. Use an outdoor scaffold in stormy or windy weather.

8.0 Frequently Ask Question

1) Is a person with a Basic Scaffolding Certificate allowed to construct acantilevered scaffold?

No

2) Is a person with a Basic Scaffolding Certificate allowed to construct a towerframe scaffold with outriggers?

Yes

3) Is a person with a Basic Scaffolding Certificate allowed to construct a mobileframe scaffold?

- Yes

4) How close to live unprotected power lines would you construct a metal scaffold?- 3m

5) How can a scaffold built alongside a road be protected from traffic damage?- 1. Re-route traffic

2. Provide guards (or fenders)

3. Use a person to direct traffic (or flagman)


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6) Name something which might corrode scaffolding equipment?- 1. Acids

2. Alkalis

3. Salts

7) What is the danger where a scaffold is being constructed close to machinery withmoving parts?

- Injury from machinery operation

8) When a scaffold is built on soil, what would you place under the baseplates todistribute the load?

-- Soleplates

9) Are gaps allowed between the planks of a working platform?- No

10)Can planks with different thicknesses be used to deck out a working platform?- No

11)When is edge protection needed on working platforms?-- When a person or object could fall more than 2m

12)What type of ladders cannot be used for access to a scaffold?-- 1. A domestic grade (or non-industrial grade) ladder

2. An extension ladder

3. A step ladder

13)What is the maximum height allowed between ladder landings?-- 6m (or 3 lifts)

14)Do castors for mobile scaffolds need wheel locks?- Yes


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9.0 REFERENCES:-

Trakhees EHS Construction Safety Regulation Dubai Municipality Code of Construction Safety Practice Occupational Safety & Health administration US Code of Practice for Access & Working Scaffold Health and Safety

Authority Ireland

Health & Safety Executive UK

Documents

GL 17 Scaffolding