Office Ergonomics Today

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Scaffolding Safety
Erecting Dismantling
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Introduction
As a person who erects and dismantles
scaffolding, your safety - and the safety of
those who will work on the scaffold - depends on
your ability to closely follow the minimum safety
requirements for constructing and using
scaffolds.
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Introduction
The scaffold system you erect will support many
workers and allow them to carry out their job
functions. How well you follow proper procedures
and safe work practices while erecting scaffolds
will have a direct affect on their safety. If you
have any questions about erecting or dismantling
scaffolding, ask your supervisor.
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Pre-planning
It is important that thorough pre-planning takes
place before scaffolding is erected. This should
include

• Evaluation and Preparation of the Site
• Identification of Any Potential Hazards
• Determining the Type of Scaffolding to be Used
• Activities to be Performed and their Weight
  Requirements
• Weight Capacity of the Scaffold

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Pre-planning
Evaluating the Site
While evaluating the site there are many factors
to consider. There may be a number of steps you
will need to take to prepare the site.
Some items to check could include
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Pre-planning

• Is the surface level and sound?
• Can the ground support the scaffold unit?
• Are there any unguarded openings or potential
  underground utility work that may affect the
  stability of the scaffold?

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Pre-planning

• Are there any nearby electrical power lines?
• If so, can the scaffold be erected while keeping
  a minimum safe approach distance from the lines?
• Can work be performed on the scaffold while
  maintaining a minimum safe approach distance from
  the electrical power lines?

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Pre-planning

• What type of pedestrian, vehicular, or equipment
  traffic will be in the area?
• What type of fall protection will be feasible?
• Will safe access while erecting and dismantling
  the scaffold be feasible?
• Will conditions such as high winds, storms, or
  icy conditions exist?

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Scaffolding Inspection
To make sure scaffold components are in good
working order, carefully inspect all scaffolding
parts before and during its erection. A defective
or damaged part could affect the integrity of the
whole scaffold.
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Scaffolding Inspection
Items to Check
Some areas to inspect include the following

• Are planks and wood components free of splits,
  rot, burns, warps, splintering, oil, or paint and
  opaque finishes that could cover potential
  defects.
• Are wood planks scaffold grade?
• Are welds and bolted connections in good
  condition.

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Scaffolding Inspection
CAUTION!

• Any defective parts must not be used.
• Any damaged or weakened scaffold part must be
  immediately repaired or removed from service
  until it is repaired.
• Never risk your safety by using damaged parts.

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Load Capacity
The load capacity of a scaffold varies, depending
on its design and application. General capacity
requirements for all scaffolds include
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Load Capacity

• The scaffold and each scaffold component must be
  capable of supporting four times the maximum
  intended load. This includes all personnel,
  equipment, and supplies.
• Direct connections and counterweights used to
  balance adjustable suspension scaffolds must be
  able to resist at least four times the tipping
  moment of the scaffold, including stall loads.

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Load Capacity

• All suspension ropes and connecting hardware must
  be capable of supporting at least six times the
  maximum intended load.
• Scaffolds must be designed by a qualified person,
  and built and loaded according to that design.
• Never overload the scaffold.

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Platform Construction
The platform surface that supports workers and
materials on the scaffold is called planks.
Planks are usually made of steel, aluminum, or
wood. Wood scaffold planks should be 2 by 10
inches, scaffold plank grade, and stamped by an
agency approved by the American Lumber Standards
Committee. Any unsafe planks should be removed
from service and clearly marked or made unusable.
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Platform Construction

• When erecting scaffolding it is most important to
  make sure the first unit of any scaffold is
  plumb, aligned, and level.
• Each platform on all working levels of scaffolds
  are required to be fully planked or decked,
  except when used only as walkways or for erecting
  or dismantling scaffolding.

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Platform Construction

• The platform and walkway must be at least 18
  inches wide.
• Install each platform unit (plank, fabricated
  deck, or fabricated platform) so that the space
  between planks, and the space between the
  platform and the uprights, is no more than one
  inch.

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Platform Construction

• The front edge of the platform must be no more
  than 14 inches from the face of the work, unless
  guardrails are used along the front edge and/or
  personal fall arrest systems are used.
• Never cover wood platforms with opaque finishes
  (such as paint), except for the edges, which may
  be covered or marked for identification.
• Never intermix scaffold components by different
  manufacturers, unless a competent person
  determines they are compatible and the scaffolds
  structural integrity is maintained.

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Platform Construction

• Each end of the platform, unless cleated or
  restrained by hooks or other means, must extend
  over the center line of its support at least six
  inches.
• If the platform is 10 feet or less in length, the
  end cannot extend over its support more than 12
  inches.
• If the platform is over 10 feet in length, its
  end cannot extend over the support more than 18
  inches.

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Platform Construction

• When platforms are overlapped to create a long
  platform, the overlap must occur only over
  supports and must be at least 12 inches, unless
  the platforms are restrained to prevent movement.
• Each abutted end of a plank must rest on a
  separate support surface.
• When the platform changes direction, any platform
  that rests on a bearer at an angle other than a
  right angle must be laid first. Platforms that
  rest at right angles over the same bearer must be
  laid second, on top of the first platform.

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Supported Scaffolds
Supported scaffolds have one or more platforms
that are supported by outrigger beams, brackets,
poles, legs, uprights, posts, frames, or similar
rigid supports. The following are some general
requirements for supported scaffolds
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Supported Scaffolds

• When using mud sills, the base plates should be
  attached to it. For added stability, it is
  recommended the mud sill be one continuous sill
  under both legs. The sill should extend at least
  12 inches beyond the center line of the pole.

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Supported Scaffolds

• All supported scaffold poles, legs, posts,
  frames, and uprights must bear on base plates,
  mud sills, or other firm foundation.
• They must also be plumb and braced to prevent
  swaying and displacement.
• Footings must be level, sound, rigid, and capable
  of supporting the load of the scaffold without
  settling or displacing.

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Supported Scaffolds

• Never use cinder blocks, bricks, gravel, loose
  fill, or other means for leveling uneven
  surfaces, or providing a foundation for the base
  plate.
• When supported scaffolds have a height-to-base
  width ratio of more than 4-to-1 (four feet of
  height for every one foot of width), then guys,
  ties, or braces must be installed at locations
  where horizontal members support both inner and
  outer legs.

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Suspension Scaffolds
Suspension scaffolds have one or more platforms
suspended by ropes or other non-rigid means from
an overhead structure. Before the suspension
scaffold is used, a competent person must confirm
that the supporting surfaces are capable of
supporting the loads imposed on them.
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Suspension Scaffolds
The following are some general requirements for
suspension scaffolds
Ropes

• NEVER use repaired wire rope as suspension rope.
• Ropes need to be inspected by a competent person
  for defects before each work shift and after any
  occurrence that could affect a ropes integrity.

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Suspension Scaffolds
Hoists

• Gasoline-powered equipment and hoists must not be
  used on suspension scaffolds.
• Gears and brakes of power-operated hoists used on
  suspension scaffolds must be enclosed.

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Suspension Scaffolds
Support Devices

• All suspension scaffold support devices (such as
  outrigger beams, cornice hooks, and parapet
  clamps) must rest on surfaces that are capable of
  supporting four times the load imposed on them.
• Two-point and multi-point suspension scaffolds
  must be tied or otherwise secured to prevent them
  from swaying if a competent person determines it
  is necessary. Never use window cleaners anchors
  for this purpose.

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Suspension Scaffolds
Outrigger Beams

• When suspension scaffold outrigger beams are
  used, they must be restrained to prevent
  movement. The inboard ends of suspension scaffold
  outrigger beams must be stabilized by bolts or
  other direct connections to the floor or roof
  deck, or by counterweights.

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Suspension Scaffolds
Counterweights

• Never use sand, gravel, or other materials that
  can be easily dislocated as counterweights. Only
  objects specifically designed as counterweights
  must be used.
• Counterweights must be secured by mechanical
  means to the outrigger beams to prevent
  accidental displacement.
• Do not remove the counterweights until the
  scaffold is disassembled.

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Suspension Scaffolds
Tiebacks

• Outrigger beams that are not stabilized by both
  bolts or other direct connections to the floor or
  the roof deck must be secured by tiebacks.
• Tiebacks must be equal in strength to the
  suspension ropes.
• Tiebacks must be secured to a structurally sound
  anchorage on the building or structure. Do NOT
  use standpipes, vents, or electrical conduits as
  anchorages.

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Access Requirements
Many scaffold-related injuries occur while
improperly getting on or off platforms. Never
jump onto a scaffold.
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Access Requirements

• When the scaffold platform is more than two feet
  above or below a point of access, then a portable
  ladder, stairway, ramp, or other means of access
  that does not affect the scaffolds stability
  must be used.
• Never use cross braces to climb onto the scaffold
  or another level of the scaffold.
• Direct access from one scaffold to another can
  only be used when the scaffold surfaces are not
  more than 14 inches horizontally and 24 inches
  vertically from each other.

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Access Requirements
Portable, Hook-On, and Attachable Ladders

• Place hook-on and attachable ladders so their
  bottom rung is not more than 24 inches above the
  scaffold support level.
• When hook-on and attachable ladders are used on a
  supported scaffold that is more than 35 feet
  high, rest platforms must be provided at least
  every 35 feet.
• The minimum rung length for hook-on and
  attachable ladders is 11-1/2 inches. Rungs must
  be uniformly spaced with a maximum spacing of
  16-3/4 inches between rungs.

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Access Requirements
Stairway-Type Ladders

• Place stairway-type ladders so their bottom rung
  is not more than 24 inches above the scaffold
  supporting level.
• Rest platforms are required at least every 12
  feet.
• The step width should be a minimum of 16 inches.
  Mobile scaffold stairway-type ladders must have a
  minimum step width of 11-1/2 inches.

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Access Requirements
Integral Prefabricated Scaffold Access Frames

• Rungs on integral prefabricated scaffold access
  frames must be at least 8 inches long.
• Rest platforms must be provided at least every 35
  feet on supported scaffolds more than 35 feet
  high.
• Rungs must be spaced no more than 16-3/4 inches
  apart.

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Access Requirements
Stairtowers (Scaffold Stairway/Towers)

• Stairtowers must be positioned so their bottom
  step is not more than 24 inches above the
  scaffold supporting level.
• Stairways must be installed between 40 degrees
  and 60 degrees from the horizontal. Each stairway
  must be at least 18 inches between stair rails.

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Access Requirements
Stairtowers (Scaffold Stairway/Towers)

• Each side of the scaffold stairway must have a
  stair rail that includes a toprail and a midrail.
  Stair rails must be between 28 inches and 37
  inches in height, from the top of the stair rail
  to the surface of the thread.
• The toprail of each stair rail system must also
  serve as a handrail, unless a separate handrail
  is provided. All handrails must provide a good
  handhold for employees.

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Access Requirements
Stairtowers (Scaffold Stairway/Towers)

• A landing platform at least 18 inches wide and at
  least 18 inches long must provided at each level.
  All treads and landing must have slip-resistant
  surfaces. Guardrails must be provided on the open
  sides and ends of each landing.

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Access Requirements
Ramps and Walkways

• All ramps and walkways that are six feet or more
  above lower levels must have guardrails.
• A ramp or walkway that is steeper than one
  vertical to eight horizontal, must have cleats
  not more than 14 inches apart that are securely
  fastened to the flanks to provide footing. Ramps
  and walkways may not incline more than a slope of
  one vertical to three horizontal.

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Access Requirements
Access for Supported Scaffolds

• When erecting or dismantling a scaffold, a safe
  means of access must be provided, if possible. A
  competent person will determine this based on
  site conditions and the type of scaffold being
  erected or dismantled.
• Hook-on or attachable ladders must be installed
  as soon as safe installation and use are
  possible.

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Access Requirements
Access for Supported Scaffolds

• When erecting or dismantling tubular welded frame
  scaffolds, end frames with horizontal members
  that are parallel, level, and not more than 22
  inches apart vertically may be used as climbing
  devices for access.

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Fall Protection
A competent person will determine if fall
protection is feasible during erecting and
dismantling procedures. Check with your
supervisor or the competent person if you are not
sure what type of fall protection is required.
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Fall Protection
Guardrail Systems

• Guardrails must be installed along all open sides
  and ends of scaffolds that are more than 10 feet
  above a lower level.
• The top edge height of toprails on supported
  scaffolds manufactured or in service after
  January 1, 2000 must be installed between 28 and
  45 inches above the platform.

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Fall Protection
Guardrail Systems

• The top edge height on supported scaffolds
  manufactured or in service before that date, and
  on all suspended scaffolds where both a guardrail
  and personal fall arrest system are required,
  must be installed between 36 and 45 inches.
• When midrails, screens, mesh, intermediate
  vertical member, solid panels, or similar
  structural members are used, they must be
  installed between the top edge of the guardrail
  system and the scaffold platform.

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Fall Protection
Personal Fall Arrest Systems

• When engineering controls, such as guardrails and
  safety nets cannot protect you from fall hazards,
  then a personal fall arrest system must be used.
  In the construction industry, a personal fall
  arrest system is required at heights of 6 feet or
  more.
• A personal fall arrest system must be attached by
  a lanyard to a vertical lifeline, horizontal
  lifeline, or scaffold structural member.

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Fall Protection
Personal Fall Arrest Systems

• The personal fall arrest system must limit free
  fall to six feet or less.
• Do not attach the personal fall arrest system to
  the guardrail system.

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Fall Protection
Personal Fall Arrest Systems

• The anchor point must be able to support 5,000
  pounds per attached worker. When vertical
  lifelines are used, the anchor point must be
  independent of the scaffold. Standpipes, vents,
  other piping systems, electrical conduits,
  outrigger beams, and counterweights are NOT
  considered safe points of anchorage.
• Inspect the personal fall arrest system before
  each use. Look for wear, tears, cuts, and other
  signs of damage.

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Falling Object Protection
A hard hat must be worn whenever there is a
possibility of being struck by falling objects,
impact while handling material at head level, or
other situations where the danger of injuries to
the head exists. OSHA (Occupational Safety and
Health Administrator) recommends that if a hard
hat is needed anywhere on the job site, then you
should wear it at all times.
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Falling Object Protection

• If tools, materials, or equipment could fall and
  strike employees below, then the area must be
  barricaded and unauthorized personnel must not be
  allowed to enter. If the platform is more than 10
  feet above a lower level, then toeboards must be
  used.
• Toeboards must be at least 3-1/2 inches high from
  the top edge of the toeboard to the level of the
  walking surface, have no more than a 1/4 inch
  clearance above the walking/working surface, and
  solid or have openings no larger than one inch in
  size.

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Falling Object Protection

• If tools, materials, or equipment are piled
  higher than the top edge of the toeboard, then
  mesh, debris nets, canopies, or other means of
  protection must be installed.

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Dismantling Scaffolding
All scaffolds must be dismantled only under the
supervision or direction of a competent person
who is qualified.

• Before dismantling scaffolding, check that it was
  erected properly and that no structural
  alterations were made.
• Make sure the correct number of ties and braces
  are in place.
• Check that all planks are correctly seated and
  will not fall as you remove other planks.

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Dismantling Scaffolding

• Lower all components to the ground by rope,
  hoist, or man-to-man. Never throw the parts to
  the ground.
• If possible, avoid leaving the scaffold partially
  dismantled, post warning notices at each point of
  access.
• Whether erecting or dismantling scaffolding, work
  should always be suspended during high winds and
  storms.

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Summit Training Source, Inc.
Contact us at 1-800-842-0466 or
at info_at_safetyontheweb.com