Supported Scaffold Safety

Objectives

Familiarize yourself with:

•Duties of a “Competent person”

•Basic scaffold requirements

NOTE: Links to the rule (WAC 296-874) and other resources are on a slide at the end of this presentation

Some Supported Scaffolds

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

What is a “Competent Person”?

A competent person is able to:

• identify existing and predictable hazards

• identify working conditionsthat are unsanitary, hazardousor dangerous and

• has authority to eliminate hazards

NOTE: This training does not make a person a “competent person” as defined by the rule.

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

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

If you don’t have inspections done…

You might go to a jobsite some day and find this!!

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.

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.

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 neededEmployees 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.

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

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 296-155 Part C-1•Must be attached to the structure or a lifeline -- not the scaffold

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

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.

Examples of lack of fall protection

Provide a ladder, ramp or direct access

For platforms more than 2 feet above or below a point of access

In the picture on right, the worker is climbing the scaffold frame, which is in violation of the rule.

Power line clearance

Insulated lines All other power lines50 – 299 volts = 3 feet 50 – 50k Volts = 10 feet

Over 50k Volts, add .4” per KV

Examples of scaffolds too close to power lines

Footings

•Support the load without settling or displacement

• Sound • Rigid• Level

Unstable Footing Examples

Platform specifications

Each working level fully planked; no more than 1” gaps

Minimum platform and walkway width of 18”

Extend end over support 6” min (Maximum end extension 12”)

Overlap planks between scaffold sections by at least 12”

Front edge within 14” of the work

Don’t paint planks since they will hide defects

Scaffold platforms must be fully planked…

(and this employee needs fall protection)

Example of improper scaffold planking

Plank cannot extend more than 18” beyond its support

Platforms

• Scaffold grade or equivalent•1,500 lb-f/in2 (stress grade) construction

lumber•Manufactured planks used according to

manufacturer’s recommendations

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.

Capacity

• 4 times the intended load + scaffold weight

• Planks must not deflect more than 1/60 of span when loaded

Downward deflection must be no more than 1.8”

10’ total plank length 6” overlap

6” overlap

Example of Overloaded scaffold

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.

Example of Unstable Support

• Forklifts and

front-end loaders

not designed by

the manufacturer

for such use.

Guying, Tying or Bracing

•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.

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.

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.

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!

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