Topics of Discussion
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Awareness
Types of Scaffolding
Scaffolding Basics
Erecting Scaffolds
Inspection of
Scaffolds
• Do’s and Don’ts
Photo of Engelmann Gym scaffold (under construction, fall 2005)
USA (v. 2008)
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Anatomy of a Fall
•
Source: Anatomy of a Fall diagram from Associated
General Contractors of Wisconsin, 6th Annual State Risk
Mgmt. Conference, Madison, 1998
USA (v. 2008)
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Scaffolding Accident/Injury Statistics
• An estimated 2.3
million construction
workers, or 65% of the
construction industry,
work on scaffolds
frequently.
• Protecting these
workers from scaffoldrelated accidents
would prevent 4,500
injuries and 50 deaths
per year.
USA (v. 2008)
2004 DOL Statistics
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Fatalities in Construction (OSHA)
Fall Protection (3 methods):
•Fall Prevention (e.g.,
guardrail system)
•Work Positioning, secures
you to a location, thus
preventing a fall
•Fall Arrest Systems,
consisting of a full body
harness, lanyard, and
anchorage
USA (v. 2008)
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Scaffolding
• A registered professional engineer must design and
certify scaffolds:
– with wood poles and
over 60 feet in height
– frame scaffolds over
125 feet in height
– outrigger scaffolds plus
scaffold erections
– when intended loads
exceed tube and
coupler scaffold
standard ratings
USA (v. 2008)
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Types of Scaffolds
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Supported Scaffolds
• Ladder Jack
• Pump Jack
• Frame or
Fabricated
• Tube and
Coupler
• Mobile
• Specialty
• Pole
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Manually Propelled
Mobile Scaffolds
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Suspended Scaffolds
• Two-Point
• Single-Point
Adjustable
• Catenary
• Multi-point
Adjustable
• Interior Hung
• Needle Beam
• Multi-Level
• Float (ship)
USA (v. 2008)
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Boatswain’s Chair
Seat slings must:
• Pass through four corner
holes in the seat,
• Cross on the underside of
the seat,
• Be rigged to prevent
slippage which could
cause the chair to be outof-level, and
• Be at least 5/8” diameter
fiber, synthetic, or other
first-grade manila rope of
equivalent criteria
(strength, slip resistance,
durability, etc.).
USA (v. 2008)
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Specialty Scaffolds
Specialty Scaffolds are designed for a narrow and very specific
range of applications. Specialty Scaffolds Include:
• Plasterers‘
• Decorators', and other largearea scaffolds;
• Bricklayers' square scaffolds;
• Horse scaffolds
• Outrigger scaffolds
• Step, platform, and trestle
ladder scaffolds
• Form and carpenter's bracket
scaffolds
• Window jack scaffolds;
• Crawling boards and chicken
ladders
• Roof bracket scaffolds.
USA (v. 2008)
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Outrigger Scaffolds
Outrigger beams must
be:
Secured in place to
prevent movement,
and
Securely braced at
the fulcrum point to
prevent tipping.
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Tube and Couple
Scaffolds
• Klotsche
natatorium HVAC
renovation
(Summer 2004)
USA (v. 2008)
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Tube and Coupler Scaffolds
Medium Duty
Light Duty
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Not to exceed 25 pounds per
square foot
10 foot longitudinal post spacing
6 foot traverse post space
•
1 work level
– 8 additional planked levels
– 125 feet maximum height
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3 work levels
– 0 additional planked levels
– 91 feet maximum height
6 additional planked levels
125 feet maximum height
2 work levels
–
–
2 work levels
– 4 additional planked levels
– 125 feet maximum height
•
Not to exceed 50 pounds per square
foot
8 foot longitudinal post spacing
6 foot traverse post space
1 work level
0 additional planked levels
78 feet maximum height
Heavy Duty
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Not to exceed 75 pounds per square
foot
6’ 6” foot longitudinal post spacing
6 foot traverse post spacing
1 work level
–
–
USA (v. 2008)
6 additional planked levels
125 feet maximum height
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Basics
• Training — Employers must
train each employee who
works on a scaffold on the
procedures to control or
minimize the hazards.
• Inspections — Before each
work shift and after any
occurrence that could affect
the structural integrity, a
competent person must
inspect the scaffold and
scaffold components for
visible defects.
USA (v. 2008)
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Basics
• Fall protection (e.g.
guardrails) required at a
10 foot height above a
lower level.
[1926.451(g)(1)]
• When erecting and
dismantling supported
scaffolds, a competent
person must determine
the feasibility of providing
a safe means of access
and fall protection for
these operations
USA (v. 2008)
NOTE: guardrails recommended at
work platform heights greater than
18
4 feet
Personal Safety Tips
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Personal Safety Tips
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Inspect Prior to Use
• All equipment
must be
inspected to see
that it is in good
condition and
serviceable.
• Damaged or
deteriorated
equipment must
not be used
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Erecting Scaffolding
• Erect plumb,
square and
rigid with all
brace
connections
securely
fastened
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Tubular Welded-frame Scaffolds
• Be sure scaffold stays plumb and level as erection progresses
• For mobile scaffolds, use a horizontal diagonal brace, for
stability, at the base and every 21 feet in height.
USA (v. 2008)
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Tubular Welded-Frame Scaffolds
• Cross members
must be locked
together with cotter
pins or equivalent
• Safway scaffolds
have “G” locks
which open with
slight pressure and
lock automatically
after guardrail slips
into place
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Overlap
• Each plank on a continuous run scaffold must
extend over its supports by at least 6” and overlap
each other by at least 12”
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Guardrails and Toeboards
• Guardrails and toeboards must be put on all open sides
and ends of scaffolds 10’ or higher
• Screening required when materials are stacked higher than
toeboard
USA (v. 2008)
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Side and End Brackets
• Side and end
brackets are
designed to support
people ONLY.
• Brackets are not to
be used on rolling
towers
• Brackets introduce
overturning and/or
uplift forces.
USA (v. 2008)
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Side and End Brackets
• Do not store
materials on side or
end bracket
platforms
• Only store materials
on scaffolds which
are for immediate
use
• Do not overload
platforms with
materials.
USA (v. 2008)
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Climbing
• Do not climb on
cross members
or railings
• Access ladders
must be used;
attachable
ladders must
extend 3 feet
above platform
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Climb Safely
• Face the rungs
• Use both hands
• Do not carry
materials while
you climb
• Keep one hand
firmly on frame or
ladder at all times
• Rungs and shoes
should be clean to
avoid slipping
USA (v. 2008)
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Mobile Scaffolds
• Height not to exceed 4* times
the minimum base dimension
•
(Example, if base is 6’ x 10’, the
maximum height is 24’)
• Planks must extend the full
length of the scaffold
• Do not ride on a mobile rolling
tower scaffold while it is being
moved.
• Guardrails and toeboards
required on all sides when
over 10 feet
* In California and some other states, height
must not exceed 3 times.
USA (v. 2008)
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Mobile Scaffolds
• All tools or other objects which
could fall from the scaffold
must be removed or secured
before moving the scaffold
• At each new location, the
scaffold shall be put on firm
ground and kept plumb
• Manual force used to move the
scaffold must be applied as
close to the base as possible,
but not more than 5 feet above
the supporting surface.
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Manually Propelled Mobile Scaffolds
• The load rating of the
casters will limit the size,
configuration, and load
capacity of the rolling
tower. Casters must be
rated 4 times the
maximum rated load of
the scaffold
• Caster and wheel stem
shall be pinned, bolted
or otherwise secured in
scaffold legs or
adjustment screws.
USA (v. 2008)
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Manually Propelled Mobile Scaffolds
• Lock all
casters
before
getting on a
rolling tower.
• Casters shall
remain
locked while
in use
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Upright Narrow Scaffold
• Per instructions of the
UpRight Narrow
Scaffold, the platform
height must not exceed
3 times the smaller
base dimension unless
scaffold is tied to the
structure
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Upright Narrow Scaffold: read the labels
USA (v. 2008)
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Upright Narrow Scaffold
USA (v. 2008)
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Inspect Job Site
• Inspect job site to
determine ground
conditions, strength
of supporting
structure, proximity
to electric lines &
overhead
obstructions
• Compensate for
uneven ground by
using screw jacks &
base plates
• Do not use unstable objects such
as blocks, loose bricks and
similar objects
USA (v. 2008)
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Ties, Guys, Bracing
• Scaffolds must be
secured to the
structure when the
height exceeds 4 times
the minimum base
width
– every 30 horizontal feet
– every 20 feet or less
(for scaffolds less than
3 feet wide) or 26
vertical feet or less (for
>3 feet wide)
– Outriggers, if used,
must be installed on
both sides
USA (v. 2008)
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Clearances
• Any work where the
tube could come into
contact with the line
would need to be 6
meters plus the
“Danger Zone”
distance relative to
the voltage and
nature of insulation in
order that the
scaffold tube cannot
enter the “Danger
Zone”
USA (v. 2008)
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Clearances
Minimum Clearances From Electrical Lines
Insulated Lines
Less than 300 volts
3 feet
300 volts to 50 kv
10 feet
More than 50 kv
10 feet plus 4” for each
additional kv
Uninsulated Lines
Up to 50 kv
10 feet
More than 50 kv
10 feet plus 4” for each
additional kv
USA (v. 2008)
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Peronsal Protective Equipment
• What types of PPE should you use when
working on or near a scaffold?
1.
2.
3.
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What’s Wrong in This Picture?
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What’s Wrong in This Picture?
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What’s Wrong in This
Picture?
• The concrete blocks are
stacked six high, there
are no base plates on
some legs, scaffold legs
are bearing on unstable
objects, and there is
improper/inadequate
bracing.
Photo & Text -- OSHA
USA (v. 2008)
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What’s Wrong in This
Picture?
• This is a shore, or lean-to
scaffold, and it is not
permitted to be used per
OSHA or ANSI.
• In this photo, workers
have a shore scaffold on
top of another shore
scaffold.
• Access is unsafe both
from above and below.
• The only thing holding
this scaffold up is the
DUMPSTER!
Photo & Text -- OSHA
USA (v. 2008)
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What’s Wrong in This Picture?
USA (v. 2008)
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What’s Wrong in This Picture?
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What’s Wrong in This Picture?
• The planks are not
cleated or
otherwise secured
against
displacement,
• There are no
guardrails, and
• There is greater
than a 14-inch gap
between the
building and the
scaffold platform.
USA (v. 2008)
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• Where ladders
end, plasterers
clamber onto
bundles of sticks
that stud the
Great Mosque.
These serve as
scaffolding --a
grid of
permanent
perches.
•
Photograph by Sarah
Leen, National
Geographic, June 2001
USA (v. 2008)
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