scaffolds construction

8/4/2019 Scaffolds Construction

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Scaffolds

OSHAX.org - The Unofficial Guide to the OSHA 1


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What Is A Scaffold?

An elevated, temporary work platform

Three basic types:

Supported scaffolds -- platforms

supported by rigid, load bearingmembers, such as poles, legs, frames,& outriggers

Suspended scaffolds -- platformssuspended by ropes or other non-rigid,

overhead support Aerial Lifts -- such as cherry pickers

or boom trucks



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Hazards


Falls from elevation caused

by slipping, unsafe access, andthe lack of fall protection

Struck by falling tools / debris

Electrocution from overheadpower lines

Scaffold collapse - caused byinstability or overloading

Bad planking giving way

Employees working on scaffolds are

exposed to these hazards:


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Fall Hazards

While climbing on or

off the scaffold Working on

unguarded scaffoldplatforms

When scaffoldplatforms or planks fail


Falls may occur:


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ProtectingWorkers from Falls

Guardrails, and/or

Personal Fall ArrestSystems (PFAS)


If a worker on a scaffoldcan fall more than 10feet, protect them by:


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Install along open sides & ends

Front edge of platforms notmore than 14 inches from thework, unless using guardrailsand/or PFAS

Top rails - 38 to 45 inches tall

Midrails halfway betweentoprail and platform

Toeboards at least 3-1/2 incheshigh

Guardrails


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Personal Fall Arrest Systems (PFAS)

You must be trained how to properly use PFAS

PFAS include anchorage, lifeline and body harness.


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Can use PFAS instead of

guardrails on some scaffolds

Use PFAS & guardrails onsuspension scaffolds

Use PFAS on erectors and

dismantlers where feasible


Fall Protection Requirements

The ends of this scaffoldare not properly guarded


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Falling Object Protection

Wear hardhats

Barricade area below scaffold

to forbid entry into that area Use panels or screens if

material is stacked higher thanthe toeboard

Build a canopy or erect a netbelow the scaffold that willcontain or deflect falling objects



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Overhead Power Lines


The possibility of

electrocution is a

serious consideration

when working nearoverhead power lines

Check the clearance

distances listed in thestandard


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Scaffold Support Examples

Good support Inadequate support in danger of collapse?


Base plate

Mud sills


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Essential Elements of Safe

Scaffold Construction Use appropriate

scaffold construction

methods

Proper scaffold access

Properly use acompetent person


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Scaffold Platform Construction

Platforms must:

be fully planked or

decked with no

more than 1 inchgaps

be able to support

its weight & 4 times

maximum load

be at least 18

inches wide


This is not a properly

constructed scaffold


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No large gaps in frontedge of platforms

Each abutted end ofplank must rest on aseparate support

surface Overlap platforms at

least 12 inches oversupports, unlessrestrained to preventmovement



Planks not properlyoverlapped


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No paint on wood platforms

Use scaffold grade wood

Fully planked between frontupright and guardrail support

Component pieces used mustmatch and be of the same type

Erect on stable and level ground

Lock wheels and braces


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Scaffold Height

The height of the

scaffold should not

be more than fourtimes its minimum

base dimension

unless guys, ties,

or braces are used


20

5


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Platform Ends

Each end of a

platform, unless

cleated or otherwiserestrained by hooks,

must extend over its

support by at least 6

inches

No Cleats


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Supported Scaffolds

Platforms supported by legs,outrigger beams, brackets,poles, uprights, posts, & frames

Restrain from tipping by guys,ties, or braces

Scaffold poles, legs, posts,frames, and uprights must be

on base plates and mud sills orother firm foundation


This support is not adequate!


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Proper Scaffold Access

Provide access when scaffoldplatforms are more than 2 feetabove or below a point of access

Permitted types of access:

Ladders, such as portable,hook-on, attachable, stairwaytype, and built-ins

Stair towers Ramps and walkways

May use building stairs and comeout window



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Scaffold Access

No access bycrossbraces

When usingladders, bottom

rung no more than24 inches high

Can use some endframes

Can access from

another scaffold,structure or hoist


End FrameDo not accessby crossbraces


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Suspension Scaffolds

Train employees to recognize hazards

Secure/tie to prevent swaying

Support devices must rest on surfaces

that can support four times the loadCompetent person: evaluate connections to ensure the

supporting surfaces can support load inspect ropes for defects before shift

PFAS must have anchors independent ofthe scaffold support system


Platforms suspended by ropes or wires. Rope must be capable

of supporting 6 times the load


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Moving Scaffolds

Employees cant be on a movingscaffold unless:

Surface is level Height to base ratio is 2 to 1 Outriggers are installed on

both sides of scaffolds

Employees cant be on scaffoldpart beyond the wheels

Competent person must be onsite to supervise


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Fatal Fact Moving a Lift

Employee was operating anaerial lift, with an extendableboom rotating work platform

The boom was fully extendedand the machine apparently ranover some bricks, causing theboom to flex or spring, throwingthe employee from the basket

The employee fell 37 feet to aconcrete surface


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Using Scaffolds

Dont work on snow orice covered platforms orduring storms or highwinds

Use tag lines onswinging loads

Protect suspensionropes from heat & acid


A covered scaffold has specialwind load considerations


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Fatal Fact Ice & No Guardrails

Laborer was working on the

third level of a tubular welded

frame scaffold which was

covered with ice and snow

The scaffold was not fully

decked, there was no

guardrail and no access

ladder

The worker slipped and fell

head first 20 feet to the

pavement below


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Overhand Bricklayingfrom Supported Scaffolds

A guardrail or personal fall arrest system is requiredon all sides except the side where the work is

being done



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Competent Person

Person capable of identifying and

promptly correcting hazards

Determines if its safe to work on ascaffold during storms or high

winds

Trains workers to recognize hazards

Selects qualified workers to conduct

work



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Scaffold Inspection

Competent personinspects scaffoldsfor visible defects

before each shiftand after anyalterations

Defective parts mustbe immediatelyrepaired


Deformed bearer


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Scaffold Erection

Scaffolds can only beerected, moved,dismantled oraltered under the

supervision of acompetent person

Competent personselects & directs

these workers anddetermines thefeasibility of fallprotection



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Training Requirements

Train employees on scaffoldhazards and procedures tocontrol the hazards

The training must include: Nature of electrical, fall, andfalling object hazards How to deal with electricalhazards and fall protectionsystems

Proper use of the scaffold Scaffold load capacities

Retrain as necessary



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Training Erectors

Train employees involved in

erecting, disassembling,

moving, operating,

repairing, maintaining, or

inspecting a scaffold to

recognize its hazards and

the correct procedures to

use



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Avoid the Main Hazards of Scaffolds

Falls from elevation

Bad planking

Scaffold collapse

Getting struck by fallingtools or debris

Electrocution



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Summary

Use appropriate scaffold constructionmethodsy Erect, move, or alter scaffold properly

y Protect from falling objects or toolsEnsure stable accessUse a competent persony Train on scaffold construction and the hazards

involved with scaffoldsy Inspect scaffold before each shift and after

alterationsy Determine fall protection requirements


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