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 rigid materials are a common sight around buildings, bridges and similar structures that are under construction or repair. The main aim of these structures is to provide safety to man & material from falling. Scaffold is an elevated platform work which is temporary is nature. There are a number of structural elements integrated in the scaffold project for protecting workers against falls. Walkways, Personal fall arrest system, erection & maintenance of scaffolds as well as Training of workers are the main elements of a scaffold system. The purpose of a working scaffold is to provide a safe working place & safe access suitable for the work being done. Most work related injuries happen when workers are working above a height of 1.5 - 2 meters. It is therefore imperative to use scaffolding which are designed and erected properly. Failure to understand and comply with all applicable safety requirements, regulations and these safety guidelines before installing, using or dismantling scaffolding can result in serious injury or death. This guideline is to prevent accidents at the workplace.

Rev. 02

Dec 2012

1Page 1 of 18

2.0 Scope: This guideline is to promote safe erection of Scaffold which is used in the Construction industry in areas within the jurisdiction of “Dubai world”. This guideline defines, identifies and describes safe methods of scaffold erection which can 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 supporting structure, the proximity with electric power lines, overhead obstructions, wind conditions and the need for overhead protection or weather protection coverings The contractor must prepare the construction design, drawing & design loads for all the scaffold used on site and must be approved by a consultant. This document must be readily available at site. The maximum height of the scaffold shall not exceed 10 meters and in case the need for higher scaffold arises the contractor shall appoint a 3rd Party for scaffold erection & supervision. All equipment’s must be inspected to see that they are in good condition. Damaged or deteriorated equipment should be reported and replaced. Wooden planks used for scaffolding must be inspected to ensure that they are sound and in good condition, straight grained, free from nails, saw cuts, splits and holes. (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 while erection of scaffold:3.1 Scaffold Foundation:Base plates are mandatory even while setting on concrete floor or Soil (i.e. soil must be compacted properly The base plate must be not be less than 5 cm thick and not less than 25 cm wide to distribute load evenly. (See figure # 01)

Rev. 02

Dec 2012

2Page 2 of 18

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 both person & material are used. The platform must be provided with standard guard rail (95 cm), which consists of mid rail & top rail The height of the toe board shall not be less than 15 cm. (see figure # 02)

Fig. 02

Rev. 02

Dec 2012

3Page 3 of 18

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 the supervision of competent persons.  Base plates must be of adequate size to distribute the loads on the scaffolding to the 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 10 meter horizontal intervals in between.

Rev. 02

Dec 2012

4Page 4 of 18

 Work platforms must be fully planked, either with scaffold graded solid sawn or laminated plank or with fabricated platforms in good condition.  Loads on plank should be evenly distributed and should not exceed the allowable loads for the type of plank being used.  Planks and/or platforms should be secured to scaffolding when necessary to prevent 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 sides and ends of scaffold platforms.  Access must be provided to all work platforms. If it is not available from the structure, access ladders or frames with built-in ladders stairways must be provided.  Side and end brackets are designed to support people only. Materials should never 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 an energized power line, to avoid any contact between scaffold component and power lines.  Check the installed scaffolding before you allow people to use it. A qualified person must thoroughly inspect the completed assembly.  Tagging system must be followed properly during erection, dismantling and when operative is working on the scaffold

Rev. 02

Dec 2012

5Page 5 of 18

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 are supported with load bearing substances like legs, poles, outriggers, frames etc. Commonly used supported scaffold are Metal Scaffold, Tube & Clam Scaffold & Frame Scaffold (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 from being affected by weather conditions.  All material used for the scaffold must be inspected regularly and maintained properly.  Scaffolding erection must be carried out by a competent person under proper supervision.  Tagging system must be followed properly during erection, dismantling and when operative is working on the scaffold.  All of the suspended scaffold must be inspected and must have valid test certificate issued by approved third party agency.

Fig.04

Rev. 02

Dec 2012

6Page 6 of 18

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 popular one is the cup-lock system scaffold where all the blades of the pipes are located in the lower cup and the upper cup is lowered down & tightened with hammer blow (see figure # 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 from being affected by weather conditions.  All material used for the scaffold must be inspected regularly and maintained properly.  Scaffolding erection must be carried out by a competent person under proper supervision.  Tagging system must be followed properly during erection, dismantling and when operative is working on the scaffold.

Fig.05

Rev. 02

Dec 2012

7Page 7 of 18

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 scaffold shall be used, proper counter weights shall be attached on the other end of the out rigger to support the scaffold. There are many types of suspended scaffolds such as suspended 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 out riggers 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 a suspended scaffold. The space between the structure and the platform shall not be more than 30 cm All suspended scaffold must be inspected and must have valid test certificate issued by approved third party agency. Tagging system must be followed properly during erection, dismantling and when operative is working on the scaffold.

Rev. 02

Dec 2012

8Page 8 of 18

Fig.06

5.4 Mobile Tower Scaffold: - A portable, wheel-mounted, caster scaffold, whether un-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 width of 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 or both.  No persons, equipment or materials are allowed to be on the platform when it is moved.  It is recommended to use a ladder (internal staircase) for access to and from the platform (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.

Rev. 02

Dec 2012

9Page 9 of 18

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.

Rev. 02

Dec 2012

Page 10 of 18 10

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, and this requires a proper safety management system to prevent any accident associated with scaffolds. The below five steps can provide a brief description of good safety management system during scaffold operation (see figure # 09)

Fig.09

Rev. 02

Dec 2012

Page 11 of 18 11

All scaffolding dose not required a design. General access/Mobile scaffold scaffolding, erected in accordance with the manufacturer’s instructions, does not require any further design. However, if a design is required then a competent scaffold designer must be engaged to design the scaffold. (See figure # 10)

Fig .10

The contractor should define a policy in relation to scaffolding. This written scaffolding policy should: Include a commitment to protect employees & other personnel working at site Require to appoint competent person for erection maintenance & dismantling of scaffold on site Include a commitment to comply with relevant health and safety legislation, & Local Regulation and relevant codes of practice and guidelines. Developing a team for scaffold and assign responsibility for choosing the type of scaffold according to design procedure

Rev. 02

Dec 2012

Page 12 of 18 12

Proper planning must be done during scaffold erection activity to minimize the risk involved Scaffolding procedure and plan must be readily available on site with all the instruction for 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 were personnel 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. Successful implementation 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

Rev. 02

Dec 2012

Page 13 of 18 13

Regular inspection is a must to determine if performance standard Periodic checking is necessary to determine if performance standards are meeting with local and other legal requirements, 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 can be 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?

Rev. 02

Dec 2012

Page 14 of 18 14

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

HIERARCHY OF HAZARDS CONTROL

Fig.11

7.0 DO’s & DON’T 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.

Rev. 02

Dec 2012

Page 15 of 18 15

7.2 DON’T  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 heavy—a 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 a cantilevered scaffold? – No 2) Is a person with a Basic Scaffolding Certificate allowed to construct a tower frame scaffold with outriggers? – Yes 3) Is a person with a Basic Scaffolding Certificate allowed to construct a mobile frame 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)

Rev. 02

Dec 2012

Page 16 of 18 16

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 with moving parts? - Injury from machinery operation 8) When a scaffold is built on soil, what would you place under the baseplates to distribute 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

Rev. 02

Dec 2012

Page 17 of 18 17

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    

Rev. 02

Dec 2012

Page 18 of 18 18