1. Supported Scaffold Safety
In this session we are going to talk about the requirements of the WISHA standard related to:
Erection
Inspection
Use
WAC Definition: Scaffold is: any temporary elevated platform (supported or suspended) and its supporting structure including anchorage used for supporting employees materials or both.

2. Objectives Familiarize yourself with: Duties of a “Competent person”
Basic scaffold requirements
NOTE: Links to the rule (WAC ) and other resources are on a slide at the end of this presentation

3. Some Supported Scaffolds
Supported scaffolds are scaffolds that are have an attachment to the ground rather than are suspended by cables.

4. What is a “Competent Person”?
A competent person is able to:
identify existing and
predictable hazards
identify working conditions
that are unsanitary, hazardous
or dangerous and
has authority to eliminate hazards
NOTE: This training does not make a person a “competent person” as defined by the rule.
Competent person” means:
one who is capable of identifying existing and predictable hazards in the surroundings or
working conditions which are unsanitary, hazardous, or dangerous to employees, and
who has authorization to take prompt corrective measures to eliminate them.
Implies:
knowledge of what the scaffolding standard requires for workplace safety
training and experience in erecting and inspecting scaffolds
Knows about the kinds of hazards that can exist around scaffolds
Is designated by management as the competent person.
Has authority to take action to stop unsafe activities and eliminate hazards identified.
NOTE: This training does not make a person a “competent person” as defined by the rule.

5. Erecting and Dismantling
A competent person determines feasibility of fall protection.
Employer must provide maximum feasible fall protection.
Questions to ask are:
Is there a nearby structure from which a lifeline can be dropped that the worker can tie off to?
Can we install guardrails immediately after installing the fabricated frames and before moving to the next level?
Can we sequence disassembly to keep the worker protected for the maximum feasible time?
Whatever is feasible to do must be done during the assembly / disassembly stages
Questions to ask are:
Is there a nearby structure from which a lifeline can be dropped that the worker can tie off to?
Can we install guardrails immediately after installing the fabricated frames and before moving to the next level?
Can we sequence disassembly to keep the worker protected for the maximum feasible time?
Whatever is feasible to do must be done during the assembly/ disassembly stages

6. Inspection by a competent person
Must occur at the beginning of each shift.
After any occurrence which could affect a scaffold's structural integrity, such as:
adverse weather
removal of parts
damaged parts
Conditions can change due to
weather
actions of workers who damage or remove parts of the scaffold or
undermine / compromise the scaffold supports.

7. If you don’t have inspections done…
You might go to a jobsite some day and find this!!

8. What do I have to do? Damaged or weakened parts must immediately be:
repaired, replaced, braced to meet minimum strength or
removed from service until repaired.

9. Or bad things can happen…
The safety of a scaffold is highly dependent upon being built right in the first place. You should have regular inspections to make sure a problem hasn’t developed over time.
When scaffolds fail, they fail in a catastrophic way and can cause many serious injuries or deaths depending on who is on or around it when it fails.

10. Worker must be trained on:
Recognizing hazards of the type of scaffold they’ll be using
Understanding the procedures to control or minimize hazards
Hazards including: electrical, falling off the scaffold, and falling objects
How to erect, maintain and disassemble the fall protection and falling object protection systems
Using the scaffold and handling materials on the scaffold
Maximum intended load and capacity
Other information as needed
So they don’t misuse the scaffold or do things that will cause it to lose its integrity, such as removing cross bracing so they can do their work. Training needs to be specific to the scaffold the workers will be using. Job-specific issues would include power line clearances, surface conditions.
According to the scaffold industry association, the five most serious scaffold hazards are:
Falls
Unsafe access
Falling objects
Electrocution
Scaffold collapse
Falls, scaffold collapse and electrocution account for most scaffold related fatalities.
A combination of regular inspection and consistent training of workers can go a long way to reducing these risks.
So, what do you need to know to be sure that scaffolds on your job site are safe? …
Employees need training so they don’t misuse the scaffold or do things that will cause it to lose its integrity, such as removing cross bracing so they can do their work. Training needs to be specific to the scaffold the workers will be using. Job-specific issues would include power line clearances, surface conditions.

11. Worker must be retrained when:
You believe an employee lacks the skill or understanding to safety erect, use or dismantle a scaffold,
If an employee's work is inadequate,
If there is a change in any of the following that presents new hazards:
Worksite
Type of scaffold
Fall protection
Falling object protection
Other equipment
So they don’t misuse the scaffold or do things that will cause it to lose its integrity, such as removing cross bracing so they can do their work. Training needs to be specific to the scaffold the workers will be using. Job-specific issues would include power line clearances, surface conditions.

12. Provide fall protection for …
employees on a scaffold more than 10 feet above a lower level by one of these methods:
guardrails, which must be:
Installed along open sides and ends and
In place before employees use the scaffold OR
personal fall arrest system
In accordance with WAC Part C-1
Must be attached to the structure or
a lifeline -- not the scaffold
Guardrails:
Along open sides and ends of the scaffold.
Must be installed before employees begin to use the scaffold.
Fall Arrest:
Lifelines attached to a fixed anchor independent of the scaffold (i.e.: not to the outrigger beam or weights of a suspension scaffold) or the frame of a supported scaffold.

13. Requirements for Guardrails
Guardrails consist of toprail, midrail and falling object protection, such as a toeboard
The toprail must be between 38” – 45” high and withstand a 200 lb. force
The midrail must be installed at a height approximately midway between the top edge and the platform surface and withstand a 150 lb. force
A toeboard, when used, must be 3 ½ inches tall and able to withstand a 50 lb. force
Top rail 38” – 45” 200 lb strength
Midrail half way between top rail and platform or vertical balusters not more than19” apart lb strength.
Toeboard (2 X 4 50 lb strength), screen or nets if employees walk or work below.
An alternative is to barricade the area around the base of the scaffold.
Top surface smooth to prevent puncture or snagging of clothes.
Manila or plastic rope rails must be inspected frequently to assure that it doesn’t deteriorate below strength requirements.
Don’t use steel or plastic banding as a top rail.
Don’t let ends of rails overhang the terminal post unless there isn’t a hazard.
You can only use cross braces in lieu of a top rail or mid rail but not both if a 19” sphere won’t pass through the resulting openings.
Cross bracing is acceptable in place of a midrail when the crossing point of two braces is between 20 inches and 30 inches above the work platform.
Install the top rail between 38” and 45”
Cross bracing can be used as a top rail when the crossing point is between 38 inches and 48 inches above the work platform.
Install the midrail ½ way between the cross point and the platform
The end points at each upright must be no more than 48 inches apart.

14. Guardrails
“X” brace can substitute for top rail or mid rail but not both.
Cross bracing is acceptable in place of a midrail when the crossing point of two braces is between 20 inches and 30 inches above the work platform.
Cross bracing can be used as a top rail when the crossing point is between 38 inches and 48 inches above the work platform.
The end points at each upright must be no more than 48 inches apart.
Top rail 38” – 45” 200 lb strength
Midrail half way between top rail and platform or vertical balusters not more than19” apart lb strength.
Toeboard (2 X 4 50 lb strength), screen or nets if employees walk or work below.
An alternative is to barricade the area around the base of the scaffold.
Top surface smooth to prevent puncture or snagging of clothes.
Manila or plastic rope rails must be inspected frequently to assure that it doesn’t deteriorate below strength requirements.
Don’t use steel or plastic banding as a top rail.
Don’t let ends of rails overhang the terminal post unless there isn’t a hazard.
You can only use cross braces in lieu of a top rail or mid rail but not both if a 19” sphere won’t pass through the resulting openings.
Cross bracing is acceptable in place of a midrail when the crossing point of two braces is between 20 inches and 30 inches above the work platform.
Install the top rail between 38” and 45”
Cross bracing can be used as a top rail when the crossing point is between 38 inches and 48 inches above the work platform.
Install the midrail ½ way between the cross point and the platform
The end points at each upright must be no more than 48 inches apart.

15. Examples of lack of fall protection

16. Provide a ladder, ramp or direct access
For platforms more than 2 feet above or below a point of access
Provide portable ladders, hook-on ladders, attachable ladders, stair towers (scaffold stairways/towers), stairway-type ladders (such as ladder stands), ramps, walkways, integral prefabricated scaffold access, or direct access from another scaffold, structure, personnel hoist, or similar surface.
Don’t climb cross braces as a means of access.
If you use a ladder more than 24 feet high, provide a rest platform every 20 feet after the first platform at 24 feet.
Make sure an attached ladder won’t tip a scaffold.
Rungs minimum 11 ½” wide X maximum 16 ¾” uniform spacing between rungs
(integral ladders like the illustration must be at least 8” wide. They can also have non-uniform spacing at the point where frame sections are joined.)
Bottom of ladder within 24” of the access point.
Stairs must have a rest platform every 12 feet.
Slip resistant tread minimum 18” wide.
Ramp: Max 20 degree slope with non-slip or cleats
Min 18” wide, guardrails if more than 4 feet above adjacent surface.
Direct access: Max 14” step across distance.
Safe access for erecting and dismantling as feasible ( per competent person). Conventional access provided as soon as possible.
In the picture on right, the worker is climbing the scaffold frame, which is in violation of the rule.

17. Power line clearance Insulated lines All other power lines
50 – 299 volts = 3 feet
50 – 50k Volts = 10 feet
Over 50k Volts, add .4” per KV
You can get closer than these distances if you contact the power company and they deenergize the lines and visibly ground them or install protective shields where exposure closer than within the above limits may occur.
A residential service drop to a weather head would be an example of under 300 volt exposure.
However, just because the wires are insulated doesn’t mean that it is safe to touch them.
They have been exposed to sun and weather for a long time and may contain cracks or other breaks in the insulation that can result in an unexpected shock upon contact.
The picture shows that there is walk-by contact on the scaffold platform. These power lines would need to be deenergized, relocated or otherwise protected against contact.
Examples of scaffolds too close to power lines

18. Footings Level Sound Rigid
Support the load without settling or displacement
Footing consists of a base plate nailed to a mud sill. A leveler is used to adjust for variations in the terrain.
A mud sill wouldn’t be needed on a concrete or asphalt surface.
You always need the base plate.

19. Unstable Footing Examples
No mudsills or base plates
Cardboard, sticks, blocks, rocks or bricks aren’t a sound method of leveling.
What happens if the pole gets nudged off the curb?

20. Platform specifications
Each working level fully planked; no more than 1” gaps
Minimum platform and walkway width of 18”
Overlap planks between scaffold sections by at least 12”
Fully decked between uprights and guardrails supports.
Platforms must be at least 18” wide
Except Ladder jack, pump jack, top plate bracket or roof bracket type scaffold must be at least 12” wide.
Except when the area is too narrow to allow 18” width guardrails or fall protection must be used.
The intent is that there be no more than 1” space between planks and uprights.
However planks can be up to 9 ½” away from the upright if you can show that the scaffold requires additional space (such as to fit around the uprights when side brackets are used to extend the width of the platform.)
Extend planks over the supporting members at least 6” unless you have tied the plank or use cleats or hooks on the underside.
Don’t extend the plank more than 12” (10’ or less plank) or
18” (longer than 10’ plank) or you could flip the plank up if you step on the extension.
Overlap planks between sections of scaffold by at least 12”.
You can only overlap over a supporting bearers.
Overlap can be less if planks are secured with cleats or tie wires
You can butt planks if each has their own support and are tied or hooked.
Overlaps can only be made above supporting bearers
Don’t paint planks since this will hide defects or damage that may only become apparent if someone falls through the plank.
Wood preservatives and non-slip finishes ok if they don’t obscure the top and bottom surfaces.
If the scaffold front edge isn’t within 14” of the wall then you must use guardrails
Except that plaster and lathing operations can be 18” away.
Extend end over support 6” min (Maximum end extension 12”)
Don’t paint planks since they will hide defects
Front edge within 14” of the work

21. Example of improper scaffold planking
Scaffold platforms must be fully planked…
(and this employee needs fall protection)

22. Plank cannot extend more than 18” beyond its support
This plank is designed to be supported at its ends with the load concentrated between the supports.
Also, if it’s not adequately secured, it can tip if you walk out past the support.
If a plank extends too far past the support because it’s too long, you can barricade access to the hazardous area.

23. Platforms Scaffold grade or equivalent
1,500 lb-f/in2 (stress grade) construction lumber
Manufactured planks used according to manufacturer’s recommendations
The standard does not specifically require scaffold grade planks.
However, the platform material you use must be able to support 4X the intended load.
If you use a manufactured plank then you need to follow the manufacturer’s instructions in terms of weight limit and distribution of that weight (uniformly over the entire span)
e.g.: three person plank has max 250 lbs at center and additional 250 lbs at 18” to the right and to the left of center.

24. Wood Plank Inspection Damaged wood planks include:
Rot, "squishy" feel, or powdery appearance from termite damage
Cupping of 3/8" or more on a 10" wide or 1/2" or more on 12" wide plank.
Crook of more than 5/16”, bow of more than 7/16” or twist of more than ¾” on a 10’ long 10” board.
Wane of more than ¼ the width and ¼ the thickness for more than ¼ the length of the plank.
A split that has a length of 1 ½ times the board width or more.
Knots that are more than 1 ½” diameter if loose or 2” diameter if tight on a 10” plank.
A notch cut into a plank more than 1/3 the plank width.
Any saw kerf cut across the plank weakens the plank by the depth of the cut. The problem may not be noticed if the plank is later laid with the cut side down.
Damaged wood planks. Damage is typically considered to include:
Rot, "squishy" feel, or powdery appearance from termite damage
Cupping of 3/8" or more on a 10" wide or 1/2" or more on 12" wide plank.
Crook of more than 5/16”, bow of more than 7/16” or twist of more than ¾” on a 10’ long 10” board.
Wane of more than ¼ the width and ¼ the thickness for more than ¼ the length of the plank.
A split that has a length of 1 ½ times the board width or more.
Knots that are more than 1 ½” diameter if loose or 2” diameter if tight on a 10” plank.
A notch cut into a plank more than 1/3 the plank width.
Any saw kerf cut across the plank weakens the plank by the depth of the cut. The problem may not be noticed if the plank is later laid with the cut side down.
Damaged manufactured planks:
Bent or cracked in hooks (DON’T repair by re-bending hook.)
Cracked rails Damaged decking
Corrosion to metal supports Loose fasteners

25. Capacity 4 times the intended load + scaffold weight
Planks must not deflect more than 1/60 of span when loaded
Scaffolds must be designed to support four times the intended load + the scaffold weight.
Planks deflect no more than 1/60 of span. For example: 10 foot plank = maximum deflection 1.8”
10’ plank minus 12” (6” overlap of supports x 2) = 9 ft x 12 in = 108 inches
108 in X 1/60 = inches

26. Example of Overloaded scaffold
Bearer – supports the planks also known as “putlog”
Runners – horizontal bracing along the length of the scaffold (may support the bearers) also known as ledger or ribbon.
Bracing – holds scaffold member rigid against another scaffold member or a structure (wall)
Cleat – block at the end of a plank to prevent it from slipping off the bearer
on top of the scaffold if it is inclined to provide traction.
Pole – vertical supporting member of the scaffold.
Base plates – support the poles and prevent them from sinking or shifting.
Ties and guys attach the scaffold to the structure at specified intervals depending on height.
Outrigger – structural member used to increase the base width
Guardrail system around the perimeter to prevent falls to a lower level
Toeboard is lower member of guardrail along planking
Platform – the work surface or planking

27. Overlaps Angled plank is not on the bottom
Not fully planked at transition
No guardrail at transition
On a corner, planks that don’t come in at a right angle to the support must be on the bottom and then overlapped by the planks that are at a right angle.

28. Example of Unstable Support
Forklifts and front-end loaders not designed by the manufacturer for such use.

29. Guying, Tying or Bracing
If the height of a scaffold is more than four times the width of the base of the scaffold
Including any outriggers, if used
You must install guys, ties, bracing or the equivalent at the closest horizontal member:
that supports both the outer and inner legs and
that is nearest the point where the scaffold height is 4 times its base width – as shown in the illustration <Click>
Install guys every 26’ above this tie point for scaffolds more than 3’ wide
(20’ above the tie point for scaffolds 3’ wide or less)
The last guy must be within the 4:1 ratio distance from the top.
Install these guys at each end of the scaffold and space additional middle guys no more than 30’ apart (as measured from one end).
If you use a cantilevered work platform (outside the framework of the scaffold), then you must use some type of bracing such as tying or outriggers to prevent the scaffold from tipping.
If the ratio of height to base is more than 4:1
Install guys every 26’ above this tie point for scaffolds more than 3’ wide.
Install these guys at each end of the scaffold and space additional middle guys no more than 30’ apart.
If you use a cantilevered work platform (outside the framework of the scaffold), then you must use some type of bracing such as tying or outriggers to prevent the scaffold from tipping.

30. Other scaffold use rules
Don’t
move a scaffold when someone is on it.
work on a scaffold covered with snow or ice.
work on a scaffold during a storm or high winds.
use boxes, barrels or a ladder on top of a scaffold to increase its height.
Do clean up debris on platforms before it accumulates.
Unless the scaffold has been designed by a registered professional engineer for movement.
You can only be on the scaffold to clear ice or snow – not to work.
Your competent person must determine if a storm or wind poses a danger to workers. If ok, then they must be protected by a personal fall arrest harness or wind screens on the scaffold.
Increasing the height of the platform with a box defeats the guardrail protection. You can use a ladder only on a large area scaffold (which fills a room) if you secure the ladder against movement and secure the platform against movement.

31. Unacceptable Scaffold Example
Shore or “lean to”
Also, a competent person must approve the use of dissimilar metals
Intermixed scaffold components must fit together without force and not effect the structural integrity of the scaffold.
Intermixed components on scaffolds can only be used if they fit together without force and don’t effect the structural integrity of the scaffold.
Dissimilar metals can’t be used unless it can be shown that galvanic action won’t reduce the strength of the component to an unacceptable level.
This is an example of a lean-to scaffold. In this picture, the 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!

32. Thank you for taking the time interest to learn about safety and health and how to prevent injuries and illnesses.