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Scaffolds in Construction
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Session ObjectivesYou will be able to:
Understand the nature of scaffold hazards
Identify major types of scaffolds and theiruse
Erect, move, operate, inspect, and maintaina scaffold
Implement safe work practices, use fallprotection, and protect yourself from fallingobjects
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Scaffolding Accidents 9% of construction-
related fatalities
There are almost10,000 scaffold-relatedinjuries each year
Loose plank a commoncause of accidents
A third of scaffolds lackguardrails
About of workers arenot properly trained
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Common Hazards of
Scaffold Work Electrical contact with
scaffolds
Slips, trips, and falls
Falling objects (toolsand equipment)
Weather-relatedhazards such as rain,
ice, and snow
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Common Types of
Scaffolds Most Common
Welded Frame
Mobile (Rolling) Two Point Suspension (Swing Stage)
Less Common
Boatswains chairs and floats
Tube and Coupler
Interior Hung (Needle Beam)
Ladder Staging
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Welded Frame and Other
Supported Scaffolds Secure to the building to prevent movement
Each tier must be placed with stacking pins
or couplings Legs on bases must be placed on firm
foundation
Each scaffold tier must be cross-braced
Full guardrails at the 10-foot level
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Welded Frame and Other
Supported Scaffolds (cont.) Footings must support
loaded scaffold
Scaffold uprights mustbe plumb and bracedto prevent swaying
Install guys, ties, andbraces to prevent
tipping Supported scaffolds
with a height-to-basewidth ratio greater than4:1 must be tied to the
structure
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Mobile (Rolling) Scaffold Height must not exceed four times the
minimum base dimension
Must be fully planked, platform secured
Never ride on a mobile scaffold unlessspecific conditions exist
Lock in place when in use
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Mobile (Rolling) Scaffold(cont.)
The casters must be able to withstand four timesthe load of the scaffold, with positive lockingdevices
Each tier must be fully braced
The platform must have full guardrails if it is 10 feetabove the ground
Power systems used to move scaffolds must be
designed for that purpose Platforms must not extend beyond base supports
Scaffolds must be leveled using screw jacks orequivalent
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Two-Point Suspension
Scaffold Inspect before installation and during use
Roof irons or hooks must be securely
installed and anchored Suspension ropes must be able to handle
six times the rated load
The platform must not be more than 36
wide.
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Suspension Scaffolds in
General Support device must rest on surface that
can support four times scaffold load
Inboard ends of outrigger beams must bebolted to structure or supported bycounterweights
Tieback strength must be equal to
suspension rope strength The platform must be secured to prevent
swaying
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Suspension Scaffolds In
General (cont.) Each rope must support six times max load
Wire ropes must be inspected prior to
each work shift for: Kinks, bends, or other physical damage
Broken wires in the strands
Abrasion, corrosion, heat damage
Repaired wire rope cannot be used
Suspension scaffolds must have emergencyor automatic braking devices
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Types of ScaffoldsAny
Questions?Any questions about the types of scaffolds
used at our construction sites?
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Scaffold Capacity Each scaffold and component must be
designed by a qualified person
It must support its own weight plus at leastfour times its maximum intended load
It must be constructed and loaded accordingto the design criteria
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Access to Platforms Use a ladder or steps
for platforms more than2 feet above or below
point of access Climbing cross braces
is not a form of access
Use proper access
Hook-on ladders Stairways and
stair towers
Inclined ramps and
walkways
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Platform Construction Working platforms
must be fully planked
Most platforms must be
at least 18 wide
Must be within 14from face of work
Must extend at least 6
over support Cantilevered platform
ends must besupported or guarded
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Long PlatformsAbutted platform ends must rest on
separate supports
Common supports may be used forplatforms specifically designed for such use
Planks must be over supports andoverlapped at least 12 or secured
At corners, the overlapped plank that is notat a right angle must be laid under the plankthat is at a right angle to the support
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Platform Components Wood platforms must not be painted
Components from one manufacturer must
not be used with those of another system Components must not be modified
Components of dissimilar metalsmust not be used together
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Guardrail Systems Must be installed along open sides and
ends of platforms
Must be in place before scaffold is releasedfor use
Top height of guardrails must be between38 inches and 45(42 standard)
Top rails must be capable of withstanding200 pounds of force
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Guardrail Systems (cont.) Midrails must be installed between top rail
and platform
Screens, mesh, or solid panels may be used Midrail systems must withstand 150 pounds
Cross braces may be used provided they donot exceed a 19-inch opening
Guardrails may not present a puncture orlaceration hazard
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Protection from Falling
Objects Wear hard hats
Use toeboards
Use screens or panelswhen items arestacked
Canopies, debris nets,or catch platforms may
be used Barricade areas below
to protect fromoverhead hazards
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Scaffold Safe Practices Scaffolds must be erected, dismantled, and
altered under supervision of a competentperson
Inspect scaffolds before each work shift
Replace damaged or weakened scaffoldcomponents
Keep scaffolds away from energizedpower lines
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Scaffold Safe Practices (cont.) Do not load scaffolds beyond their rated
capacity
Do not move scaffolds horizontally while youare on them
Do not work on scaffolds that are coveredwith snow or ice
Do not work on scaffolds during stormsor high winds
Debris should not be allowed to accumulateon platforms
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Ladders on Scaffolds Ladders are prohibited except on large
area scaffolds
Ladders must be secured against sidewaysmovement
Platforms must be secured to the scaffold
Ladder legs must be prevented from
slipping off platform You are not permitted to stand on boxes or
other items
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Fall Protection Required when
working 10 feet abovea lower level
Use approved personalfall arrest system
Use guardrail system
Suspension scaffolds
require both
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Personal Fall Arrest
System Vertical lifelines must be fixed to anchor
independent of scaffold
Vertical lifeline must not be anchored to thesame point as suspension ropes
Horizontal lifelines must be secured to twoor more points of scaffold
Suspension scaffolds must be equippedwith additional support lines
Anchorage must support 5,000 lb
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Any Questions?Any questions about the safety
specifications of scaffolds?
Any questions about safe work practiceswhile working on a scaffold?
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Key Points to Remember Inspect the scaffold before each work shift
Properly secure platforms
Do not overload scaffolds
Wear personal fall arrest system
Understand scaffold hazards and followaccident prevention measures