Scaffold 0c8be2a1 9996-490a-99c0-6ef40baed98a

OSHA 10-Hour Construction Course: Module 5 – Scaffolds of 22

OSHA MODULE 5 – Scaffolds Learning Objectives Upon completion of the lesson, participants will be able to:

• Name the three types of scaffolds and describe their main characteristics • List at least three of the four main hazards to which persons working on a

scaffold are exposed, and describe at least one method of hazard prevention for each of the hazards.

• Identify the three essential elements of safe scaffold construction, and give at least three examples of incorporating each of the elements.

Introduction

An estimated 2.3 million construction workers, or 65 percent of the construction industry, work on scaffolds frequently. In 1996, when OSHA issued the revised Scaffold Standard for construction, the agency estimated that by protecting these millions of workers from scaffold falls, 4,500 injuries and 50 deaths from scaffold-related accidents would be prevented every year. In addition to this human savings, working safely on scaffolds also has financial rewards, with an estimated annual savings of $90 million for American employers in workdays not lost. By definition a scaffold is a temporary, elevated platform that construction workers use for working safely at elevations. Scaffolds have been around for thousands of years, and there are myriad types and uses. Some simple scaffolds are little more than planks and guardrails over two sawhorses; others are much more complex, such as the scaffolds erected hundreds of feet in the air to build skyscrapers or repair monuments like the Statue of Liberty. Scaffolds are fabricated from many materials—some common, and others not so common. As an example, even in this day of steel and iron, scaffolds made from bamboo sticks are still used in some Asian countries to erect large multistory structures. In the United States and Canada, most scaffolds found at jobsites are made of steel, aluminum, or less commonly, wood. Frequently used types of scaffolds include the fabricated frame scaffold, the mobile scaffold, the tube and coupler scaffold, the system scaffold, and the suspended scaffold. There are many other scaffolds in use as well, each with advantages and disadvantages. The knowledgeable user knows how to select the right scaffold for the job, and he should—his life depends on it. Using scaffolds properly can help prevent workplace accidents and injuries. Knowing what to do and when to do it can save lives. A thorough understanding of all aspects of constructing, using, and dismantling a scaffold is vital to protecting workers. Each has potential hazards that employers and workers need to be aware of so they can take the proper measures to protect against or prevent accidents and injuries.


The OSHA standard - 1926.451 Subpart L - sets performance-based criteria to protect employees from scaffold-related hazards such as falls, falling objects, structural instability, electrocution, or overloading. It also addresses training and various types of scaffolds as well as falling object protection, ladders, weather conditions, aerial lifts, stilts, and other issues that are not covered in OSHA’s previous scaffolding standards. In addition, it allows employers more flexibility when using protective systems for workers on scaffolding. As with most other OSHA regulations, the responsibility for meeting the standard is placed on the employer, who must have a competent person, who is, by definition, the “one capable of identifying existing and predictable hazards...and who has authorization to take corrective measures to eliminate them.” A scaffold can only be erected, moved, dismantled, or altered under the supervision and direction of a competent person qualified in such activities. The competent person selects, directs, and trains the employees who erect, dismantle, move, or alter scaffolds. He or she also determines the feasibility of fall protection and safe access during erection.

It is also mandatory that the competent person inspect the scaffold before the start of each work shift, as well as after any occurrences that could affect the integrity of the scaffold, such as a carpenter having removed a brace to reach his work, or the discovery of a broken component.

Let’s take a look at the stages of scaffolding—building, using, and dismantling—and identify their hazards. How Are Scaffolds Built? Before building a scaffold, all persons involved in the process must wear required, appropriate personal protective equipment (PPE), for protection from the hazards present at the job site. Generally, safety boots or shoes, eye protection, and hard hats meeting OSHA standards are a minimum requirement on a construction site. Other specialized equipment may also be required under certain circumstances, such as gloves, fall protection harnesses and equipment, and personal flotation devices. The first step in building a scaffold includes a site inspection to:

• Identify site-specific hazards not identified in the preplanning stage, and • Ensure that the specific characteristics of the site are considered in the scaffold

design Meanwhile, erectors should inspect all scaffold parts before use, checking for:

• Cracks • Dents • Bends • Breaks • Corrosion, and/or • Bad welds

on all metal pieces.


Fittings need to be scrutinized for distorted, stripped, missing, or bent parts, and scaffold planks need to be checked for cracks, splits, or other damage. To prevent the use of inappropriate planking, the competent person should specify that all planks be marked “scaffold grade or equivalent.” Planks should not be coated with opaque paints, because the paint may hide defects. There can be no large gaps in the front edge of the platform, and each abutted end of a plank must rest on a separate support surface. Platform Ends Each platform end 10 feet or less shall not extend more than 12 inches beyond its support unless the platform is designed and installed so that the cantilevered portion is designed by the competent person to support employees or materials without tipping, or has guardrails that prevent employee access to the cantilevered end. Each platform more than 10 feet long should not extend more than 18 inches over its support, unless all the other conditions mentioned for platform ends 10 feet or less also apply. Once the site inspection has been completed, the process of actually building the scaffold can begin under the supervision and direction of the competent person. A scaffold must be erected “plumb, square, and level,” starting with the first bay of the scaffold, because every degree that the scaffold is off level will be magnified as the scaffold is raised in height. If the scaffold is built even a few degrees off plumb, the resulting instability could cause the weight of the scaffold to shift, potentially causing the overloading of one leg and the eventual collapse of the scaffold. The ramifications of a disaster of that magnitude could be at best costly, and at worst, tragic. All diagonal, horizontal, or other bracing recommended by the manufacturer or qualified person must be installed as the scaffold is erected. Supported scaffolds with a height more than four times the minimum base width (4:1) must be tied, guyed, or braced. The braces have to be installed according to the manufacturer’s recommendations, but at a minimum, the scaffold must be tied closest to the 4:1 height and then repeated every 20 feet vertically for a scaffold 3 feet wide or less, and every 26 feet for a scaffold greater than 3 feet wide. The guys, ties, or braces must be placed horizontally at each end and at 30-foot intervals measured from one end only. As the scaffold is built level by level, builders must have a means of safe access. There are specific OSHA requirements for safe access for scaffold builders, dismantlers, and users. Some frame scaffolds meet these requirements with built-in ladders that have the proper spacing between rungs. For scaffolds without this feature, builders must install ladders. Using cross braces for access is not permitted by the OSHA scaffold standard. Decking or planking used by the builders must be at least 18 inches wide. After the building process is complete, it is important that all “working” levels of the scaffold are fully planked. Unless the employer can demonstrate that wider spacing is necessary in a particular scaffold installation, there should be no more than a 1-inch space between planks. Scaffold levels used only as a walkway must have planking or decking at least 18 inches wide or fall protection must be provided and used. Before builders can permit the use of a scaffold, fall protection systems and falling object protection must be installed on any scaffold more than 10 feet above a lower level. The


fall protection system can consist of guardrails, a personal fall protection system (PFAS) with a body harness, lifelines, and anchor points, or other equally effective means of preventing falls from the scaffold. The guardrail system must protect all open sides and ends of the scaffold. If the decision to use personal fall protection systems is made, it is important that a person who is competent in fall protection review the plan and approve any anchor points. The scaffold could potentially collapse if an employee “tied off” to the scaffold falls, so the competent person will have to consult with the scaffold manufacturer before making a decision regarding anchor points on a scaffold. To protect employees from falling objects, toeboards or other effective means—such as debris nets, canopies, or screens—need to be installed. The area below the scaffold should also be barricaded to prevent entry by unauthorized persons. However, the major protection is always to wear a hard hat! When potential falling objects might be too large to be held by conventional toeboards, screens, panels or guardrails, it is the employer’s responsibility to place those objects far from the edge of any surface from which they could fall, and the materials must be secured to prevent them from falling. Always be aware, too, of employees working on levels below you and be especially careful not to allow heavy tools, objects, etc. to somehow “slip through the cracks” around employer-supplied barricades. How Are Scaffolds Used Safely? All persons who build or use scaffolds must receive training in the proper use of the scaffold and hazards associated with this activity per OSHA.

The employer shall have each employee who performs work while on a scaffold trained by a person qualified in the subject matter to recognize the hazards associated with the type of scaffold being used and to understand the procedures to control or minimize those hazards. The training shall include the following areas, as applicable:

• The nature of any electrical hazards, fall hazards and falling object hazards in the work area;

• The correct procedures for dealing with electrical hazards and for erecting, maintaining, and disassembling the fall protection systems and falling object protection systems being used;

• The proper use of the scaffold, and the proper handling of materials on the scaffold; and

• The maximum intended load and the load-carrying capacities of the scaffolds used.

The employer also needs to train each employee who is involved in erecting, disassembling, moving, operating, repairing, maintaining, or inspecting a scaffold trained by a competent person to recognize any hazards associated with the work in question. The training shall include the following topics, as applicable:

• The nature of scaffold hazards;


• The correct procedures for erecting, disassembling, moving, operating, repairing, inspecting, and maintaining the type of scaffold in question;

• The design criteria, maximum intended load-carrying capacity and intended use of the scaffold; and

• Any other pertinent requirements of this subpart.

OSHA 1926.454(c) states:

“When the employer has reason to believe that an employee lacks the skill or understanding needed for safe work involving the erection, use or dismantling of scaffolds, the employer shall retrain each such employee so that the requisite proficiency is regained.”

During this training, in addition to the mandatory items in the OSHA regulations, the competent person should establish and communicate the jobsite rules to the scaffold users. These and any other rules to be implemented should be put in writing, taught to all employees, and made part of the corporate culture. Resources for safe scaffold use include training courses given by various organizations. The OSHA Training Institute (OTI) provides a 4-day course, Principles of Scaffolding, which focuses on the safety aspects of scaffolding and current OSHA requirements. Students learn the basics of scaffolding operations from installing to dismantling. Topics include built-up scaffolds, suspension scaffolds, and interpretation of related standards. The training includes a demonstration of scaffold installing and dismantling method as well as a 1-day field exercise. Examples of Scaffolding Rules

• Workers will use only the installed ladders for access and will never climb a scaffold using the cross braces or guardrails as ladders

• Scaffolds must never be modified by anyone without permission from the supervisor designated as a “competent person”, including “just removing that brace for a minute to paint behind it....” or doing other seemingly harmless activities

• Any damage to the scaffold has to be reported to the competent person immediately

• Scaffolds cannot be used in high winds or electrical storms; the competent person has the final word on what constitutes these prohibited conditions

• Snow and ice must be cleared from the scaffold before workers attempt to use it Removing Scaffolding Scaffolds should only be dismantled by employees who have been trained by the competent person to recognize the hazards inherent in scaffold erection and dismantling. Dismantling is the reverse of the building process with the same potential exposures to falls, electrocution, and other hazards. All work should be conducted from the top down. It is very important that workers at lower levels not get ahead of the dismantlers by removing braces, planking, or guardrails to “speed up the job.” When lowering the scaffold components to the ground, care must be taken not to damage the components by dropping them or throwing them around. Finally, the scaffold


components should be cleaned as necessary, inspected, repaired, and stored in a manner that will prevent corrosion or other damage. Types of Scaffolding Here we review some of the scaffold types used on jobsites, give a bit of detail on their designs, their more common uses, and their limitations and hazards. There are three basic types of scaffolds, from which many other formulations are derived (though there are also other unique assemblies as well). The three main scaffold types are supported scaffolds, suspended scaffolds, and aerial lifts. Supported scaffolds are comprised of one or more platforms supported by outrigger beams, brackets, poles, legs, uprights, posts, frames, or similar rigid supports. Suspension scaffolds are comprised of one or more platforms suspended by ropes or other non-rigid means from an overhead structure. Aerial lifts are vehicle-mounted devices such as cherry pickers or boom trucks used to get a worker to an elevated position. Fabricated Metal Frame Scaffolding Design

• Uses cross braces to connect prefabricated frames together. The size of the frames, as well as the length and type of the planks laid between them, dictate the maximum load possible.

Use

• Widely used at many jobsites due to simple assembly, rigid construction, low cost, and durability.

• Can be erected up to 125 feet in height. • Available in different configurations and weight ratings to accommodate many

types of work such as masonry and plaster work. Limitations/Hazards

• Rigid prefabricated construction makes it less adaptable to unusual building shapes than other scaffold types such as the tube and coupler or the system scaffold

• Fabricated frame scaffolds more than 125 feet high must be designed by a registered professional engineer

• Deenergize, guard, or mark all electrical hazards and keep all conductive materials at least 3 feet from electrical hazards (10 feet or more above 300 volts)

• Scaffold frames and panels must be attached together with pins, couplers, or equivalent devices

• Scaffolds must rest on base plates and mudsills, or other firm foundations capable of supporting the loaded scaffold without settling or displacing


Mobile Scaffold (Manually Propelled Rolling Tower) Use

• Ideal for work involving repetitive tasks at the same height in different places, such as checking the fire sprinkler heads in a warehouse.

Design

• Can be a specifically designed construction, but often is simply a fabricated frame scaffold mounted on locking wheels known as casters.

• Has additional diagonal bracing for rigidity. • Can use outrigger supports to widen the base for greater stability.

Limitations/Hazards

• Use on flat, smooth surfaces • This scaffold can be easily pushed into electrical wires. Deenergize, guard, or

mark all electrical hazards and keep all conductive materials at least 3 feet from electrical hazards (10 feet or more for electrical hazards exceeding 300 volts)

• Rubber casters often have a limited load capacity compared to metal casters of the same size, and this may limit the maximum load the scaffold can support

• Generally limited in height to two times the minimum base dimension or a maximum height of 20 feet when employees remain on it while it is moved

• Casters must be locked after each move • Apply manual force as low as possible, and no higher than 5 feet from the floor

surface when pushing the scaffold from one position to another Tube and Coupler Scaffold (Tube and Clamp Scaffold) Design

• Four basic parts—base plate, tube, right-angle clamp, and swivel clamp—combine to form a scaffold of almost infinite shape and size.

Use

• For placing elevated work platforms around structures with complex shapes. • Can be erected up to 125 feet in height before requiring approval from a qualified

engineer. • Can be erected around and in tight places such as petrochemical or power-

generating plants. Limitations/Hazards

• Tube and coupler scaffolds over 125 feet high must be designed by a registered professional engineer and be constructed and loaded in accordance with such design.

• Deenergize, guard, or mark all electrical hazards and keep all conductive materials at least 3 feet from electrical hazards (10 feet or more for electrical hazards exceeding 300 volts).

• Follow the blueprints for erection, install all bracing exactly as drawn. • Scaffolds must rest on base plates and mudsills, or other firm foundations

capable of supporting the loaded scaffold without settling or displacing.


System Scaffold Use

• Like the tube and coupler scaffold, this system can be used to erect platforms around complex structures.

Design

• Similar to the tube and coupler scaffold except that instead of couplers (clamps) specialized end-fasteners function as an integral unit of the scaffold component, allowing for quick and easy erection of scaffolding in less time.

• Proponents of the system scaffold believe that the relatively high initial purchase cost is more than offset by the savings in time and manpower required each time the scaffold is assembled and disassembled.

Limitations/Hazards

• End-fasteners are unique to each manufacturer, and a variety of specialized parts may be required, thereby increasing the initial cost of the scaffold inventory.

• Deenergize, guard, or mark all electrical hazards and keep all conductive materials at least 3 feet from electrical hazards (10 feet or more for electrical hazards exceeding 300 volts).

• Scaffolds must rest on baseplates and mudsills, or other firm foundations capable of supporting the loaded scaffold without settling or displacing.

• Consult the manufacturer before mixing components from different manufacturers.

Suspended Scaffold Design

• Rigged on cable or rope so that it hangs down from a structure. • Can have single or multiple points of attachments on the structure.

Use

• A single-point suspended scaffold like a boatswain’s chair is simply a rope attached to a special harness that a worker sits in as he or she is raised and lowered up and down the structure.

• A two-point suspended scaffold consists of a platform and two ropes and hoists, such as that frequently used by window washers on large buildings.

• Multipoint suspended scaffolds consist of two or more ropes, hoists, and platforms that can be linked together in a straight line or at angles to conform to buildings with unusual shapes.

Limitations/Hazards

• This assembly can be very complex, and multiple hoists present hazards when raising and lowering work platforms since it is possible to raise one side and lower the other or to create gaps between platforms through which employees can fall.

• Because this type of scaffold is suspended from the structure, great care also must be used to ensure that the roof and parapet of the structure can support the additional weight imposed by the scaffold.


• Only items specifically designed as counterweights shall be used to hold down scaffold outriggers. Construction materials such as bags of sand or rolls of roofing felt are not acceptable for this use.

Pump Jack Scaffold

Design Pump jacks are a uniquely designed scaffold consisting of a platform supported by moveable brackets on vertical poles. The brackets are designed to be raised and lowered in a manner similar to an automobile jack.

• Pump jack brackets, braces, and accessories must be fabricated from metal plates and angles.

• Each pump jack bracket must have two positive gripping mechanisms to prevent any failure or slippage.

Use • Pump jacks are appealing for certain applications because they are easily

adjusted to variable heights, and are relatively inexpensive.

• Poles must be secured to the structure by rigid triangular bracing, or equivalent, at the bottom, top, and other points as necessary

Limitations/Hazards

• When poles are made of wood, the pole lumber must be straight-grained, free of shakes, and free of large loose or dead knots, and other defects that might impair strength.

• When wood poles of two continuous lengths are joined together, the seam must be parallel to the bracket


• To develop full strength when two-by-fours are spliced to make a pole, mending plates must be installed at all splices

• When guardrails are used for fall protection, a workbench may be used as the

toprail only if it meets all requirements of paragraphs 1926.451(g)(4)(ii), (vii), (viii) and (xiii)

• Work benches must not be used as scaffold platforms

• When bracing already installed has to be removed so the pump jack can pass, an additional brace must be installed approximately 4 feet above the original brace before it is removed. The additional brace must be left in place until the pump jack has been moved and the original brace reinstalled.

Ladder Jack Scaffold

Design • A ladder jack scaffold is a simple device consisting of a platform resting on

brackets attached to a ladder

• Ladder jacks must be designed and constructed to bear on the side rails and ladder rungs, or the ladder rungs alone

If ladder jacks bear on the ladder rungs alone, the bearing area must include a length of at least 10 inches on each rung

• Ladders used to support ladder jack scaffolds must be placed to prevent slipping, fastened to prevent slipping, or equipped with devices to prevent slipping

Use Ladder jacks are primarily used in light applications because of their portability and cost effectiveness.


Limitations/Hazards

• All ladders used to support ladder jack scaffolds must comply with 1926 Subpart X—Stairways and Ladders

o Exception: Job-made ladders must not be used to support ladder jack scaffolds

• Platforms should not be placed higher than 20 feet from the supported base

• Scaffold platforms must not be bridged together Pole or Wood Pole Scaffold

Design Pole scaffolds are a type of supported scaffold in which every structural component, from uprights to braces to platforms, is made of wood. OSHA has standards for two kinds: single-pole, which are supported on their interior side by a structure or wall, and double-pole, which are supported by double uprights independent of any structure.

• Crossbracing must be installed between the inner and outer sets of poles on double pole scaffolds.

• Diagonal bracing must be installed in both directions across the entire outside face of double- and single-pole scaffolds and the entire inside face of double-pole scaffolds used to support loads of 50 lbs. or more per square foot.

• Runners and bearers must be installed on edge. Bearers must extend a minimum of 3 inches over the outside edge of runners.

• Runners must extend over two poles at minimum, and be supported by bearing blocks securely attached to the poles.


• Braces, bearers, and runners must not be spliced between poles.

Use

• These scaffolds are no longer common as they are expensive and labor-intensive to build, but when they are constructed, they are used for any variety of medium- to heavy-duty applications

• When platforms are moved to the next level, the existing platform must be left

undisturbed until the new bearers have been set in place and braced. Limitations/Hazards

• Pole scaffolds over 60 feet in height must be designed by a registered professional engineer, and be constructed and loaded in accordance with that design.

• Because they have to be built from scratch and cannot easily be reused, pole

scaffolds are considered old-fashioned and are rarely used today. Case Studies Suspension scaffolds in particular had a poor track record prior to 1996, when falls from scaffolds led to an overhaul of the OSHA standard for scaffolds in construction. Let’s take a quick look at some of the history and statistics:

Fatal falls from scaffolds during the period 1980-85 accounted for 17 percent of all falls from elevations, second only to falls from buildings [Source: Bobick 1988; NIOSH 1991a].

Falls from scaffolds accounted for 21 percent of fatal falls from working surfaces reported for the period 1974 to 1978 [OSHA 1979]. Suspension scaffolds were involved in 30 percent (25 of 82 incidents and 27 deaths) of the falls from scaffolds. Of the 25 falls from suspension scaffolds, 68 percent (17) involved scaffold equipment failure. Personal fall protection equipment was used in only three of these incidents, but it was used improperly in each case. In one incident, a worker fell out of his improperly fastened safety belt; in the other two incidents, excessively long lanyards broke or separated after victims fell 30 feet.

The NIOSH Fatal Accident Circumstances and Epidemiology (FACE) Program began investigating fall-related fatalities among workers in October 1988. Their findings included five case reports of falls from suspension scaffolds that resulted in the deaths of six workers between October or 1988 and November of 1989. Here we will look over the facts from three of them.

Case #1

On November 15, 1988, a 53-year-old male painting foreman and a 28-year-old male painter died when the scaffold from which they were working collapsed, causing them to fall nearly 48 feet to the ground. The men were painting the exterior of a 48-foot- high, 56-foot-diameter storage tank. They were painting the side of the tank from a two-point


suspension scaffold supported by two steel outriggers. The scaffold manufacturer specified 600 pounds of counterweight for this scaffold and load, but the painters had rigged the scaffold using only 200 pounds of counterweight (100 pounds per outrigger). The outriggers were not tied off or otherwise secured.

No personal fall protection equipment was being used by either worker. While the two men were working on the scaffold, their weight caused the outriggers to slip, and the scaffold, rigging, and victims fell to the ground. [Source: http://www.cdc.gov/niosh/92-108.html]

Case #2

On December 19, 1988, a 27-year-old male cement finisher died when he fell from a suspension scaffold and his safety lanyard snapped. The victim and a coworker were dismantling suspended scaffolding at the 160-foot level inside a 172-foot-high, circular concrete silo. Both men were wearing safety belts with nylon rope lanyards secured to independent lifelines.

The accident occurred when the victim lost his balance and fell off an unguarded end of the scaffold. The coworker stated that he saw the victim fall and jerk upward as the lanyard caught him. When the victim's weight dropped back on the lanyard, it snapped, allowing him to fall onto a concrete floor.

Examination of the lanyard after the event showed burn damage at several places, including the point of failure. The employer did not control inspection or distribution of this fall protection equipment. Instead, the equipment was kept in a common supply bin where the workers could readily obtain it when needed and return it when work was completed. The lanyard had been returned to the storage bin even though it had probably been damaged earlier during cutting and welding operations. [Source: http://www.cdc.gov/niosh/92-108.html]

Case #4

On October 21, 1989, a 37-year-old male painter died when the platform he was working from fell 65 feet inside a municipal water storage tank. The victim was a member of a three-man crew that was using an improvised suspension scaffold to paint the interior of the 68-foot-tall, 32-foot-diameter water tank. The scaffold consisted of an aluminum ladder used as a platform and secured to steel "stirrups" made of steel bar stock bent into a box shape and attached to each end of the ladder. Wire cables from each stirrup ran to a common tie-off point. A cable from this common tie-off was rigged to a block and tackle used from ground level to raise and lower the platform. The block and tackle supporting the system was secured to a vertical steel pipe on top of the tank with a cable that was fashioned into a loop by U-bolting the dead ends of a piece of wire rope.

The victim had been painting from one end of this scaffold while wearing a safety belt and lanyard attached to an independent lifeline. When the victim finished painting, he unhooked his lanyard from his lifeline and moved along the ladder platform to a position where he could hand his paint spray gun to the foreman (who was at the top of the tank). As the foreman took the spray gun, he heard a "pop" and saw the scaffold and the victim fall 65 feet to the floor of the tank.


Investigation of the incident revealed that the two U-bolts on the loop of cable supporting the block and tackle had loosened enough to allow the cable ends to slip through, causing the scaffold to fall. This particular rig had been used without incident every day for 2 weeks preceding this fatal fall.

Conclusions

The fatal incidents reported here all involved violations of today’s newer (1996) OSHA regulations for scaffolds. These regulations include the use of proper scaffold equipment, appropriate installation of equipment, use of proper operating procedures, use of prescribed personal fall protection equipment, and adequate training of workers.

None of the deaths described here would have occurred if the existing and proposed OSHA regulations for the safe use of scaffolds had been observed!

Reminders

NIOSH recommends the following measures to prevent serious injuries and fatal falls while working from suspension scaffolds:

1. Comply with the current and proposed OSHA regulations for working with scaffolds.

2. Assure that design and construction of scaffolds conform with OSHA requirements.

3. Shield scaffold suspension ropes and body belt or harness system droplines (lifelines) from hot or corrosive processes, and protect them from sharp edges or abrasion.

4. Inspect all scaffolds, scaffold components, and personal fall protection equipment before each use.

5. Provide personal fall protection equipment and make sure that it is used by all workers on suspension scaffolds.

6. Use structurally sound portions of buildings or other structures to anchor droplines for body belt or harness systems and tiebacks for suspension scaffold support devices. Droplines and tiebacks should be secured to separate anchor points on structural members.

7. Provide proper training for all workers who use any type of suspension scaffold or fall protection equipment.

8. Follow scaffold manufacturers' guidance regarding the assembly, rigging, and use of scaffolds.

Additional Requirements for Specific Types of Scaffolds As mentioned earlier, there are a number of specialized scaffolds that have special OSHA requirements. The summary of the final rule, found in the document Safety Standards for Scaffolds Used in the Construction Industry, §1926.450, Subpart L, Scaffolds, states:


“Section 1926.452 of the final rule contains requirements that supplement the requirements of §1926.451 with regard to particular types of scaffolds. The identified scaffolds have unique features which require specific attention. OSHA has determined that compliance with the performance-oriented provisions official rule §§1926.451 and 1926.452, taken together, will provide adequate protection for employees working on scaffolds.” By accessing the document above, you will find a detailed explanation of the updated special requirements for a plethora of specialty scaffolds. Here are two examples of the type of information you’ll find: Pole scaffolds over 60 feet in height must be designed by a registered professional engineer. Bricklayer’s square scaffolds (“Squares”) made of wood must be reinforced with gussets on both sides of each corner; diagonal braces must be installed on all sides of each square; diagonal braces must be installed between squares on the rear and front sides of the scaffold, and extend from the bottom of each square to the top of the next square; and scaffolds of this type must not exceed three tiers in height and must be constructed and arranged so that one square rests directly above the other, and the upper tiers must stand on a continuous row of planks laid across the next lower tier and be nailed down or otherwise secured to prevent displacement. These examples are not complete, but provide a general idea of the type of information you’ll need depending on the type of scaffolding you use. You’ll undoubtedly come across many different types of scaffolds during the course of your construction career, including those such as a carpenters' bracket scaffold, a catenary scaffold, and a float scaffold. Scaffold Fall Protection If a worker on a scaffold can fall more than 10 feet, they must be protected by guardrails and/or personal fall arrest systems (PFAS). The type of fall protection required will depend upon the type of scaffold being used. Falls from scaffolding most often occur when employees are climbing onto or off of a scaffold, when working on an unguarded scaffold platform, or when a scaffold platform or one of its planks breaks. Guardrail requirements were covered earlier in the course, but to reiterate the more important points, they must be installed along the open sides and ends of a scaffold and have a minimum height of 38 inches (36 inches where PFASs are the primary fall protection). Midrails are used halfway between the toprail and the platform, and toeboards must be at least 3 and ½ inches high. When crossbracing is used as a midrail, it must be between 20 and 30 inches above the work platform.


Guardrails are not required when:

• The front end of all platforms is less than 14 inches from the face of the work • Outrigger scaffolds are 3 inches or less from the front edge • Employees are plastering and lathing 18 inches or less from the front edge

Personal fall arrest systems were also covered in the PPE module, but a quick overview reminds us that they consist of an anchorage, connectors, and a body harness, and may include a lanyard, deceleration device, lifeline, or combinations of these. A few key requirements:

• There should be no free fall more than 6 feet. • There should be prompt rescue after a fall. • Inspect PFAS’s prior to each use. • Don’t use PFAS’s until they’ve been inspected by a competent person.

A competent person must determine the feasibility and safety of providing fall protection for employees erecting or dismantling supported scaffolds. What Fall Protection Will I Need for Scaffold Work?

• For a boatswain’s chair, a centenary scaffold, float scaffold, needle beam scaffold, or ladder jack scaffold, a PFAS is required.

• For a single-point or two-point adjustable scaffold, you’ll need a PFAS and a

guardrail system.

• For a crawling board (chicken ladder) you’ll need a PFAS, a guardrail system or a ¾-inch diameter grabline or equivalent handhold securely fastened beside each crawling board.l

• On a walkway within a scaffold, you’ll need a guardrail system installed within 9

and ½ inches of and along at least one side of the walkway.

• On a supported scaffold when performing overhand brick laying operations, a PFAS or guardrail system is necessary on all open sides and ends of the scaffold.

• For all other scaffolds, a personal fall arrest system or guardrail system is in

order. Don’t use Shore or Lean-To Scaffolds! A shore scaffold is a supported scaffold that gets its support from being placed against a building or structure and held in place with props. A Lean-to scaffold is a supported scaffold that is kept erect by tilting it toward and resting it against a building or structure. One other “don’t” to remember is not to load scaffolds or scaffold components in excess of their maximum intended loads or rated capacities, whichever is less.


The Cold, Hard Facts Don’t work on snow or ice covered platforms, or during electrical storms or high winds. Use tag lines on swinging loads.

Suspension ropes and droplines for body belt or harness systems should be shielded from:

• Heat-producing processes such as welding, • Acids or other corrosive substances, and • Sharp edges or abrasions.

Such ropes should also be made from material that is not adversely affected by heat or by acids or other corrosives.

To help summarize fall protection when working on a scaffold, NIOSH recommends the following measures to prevent serious injuries and fatal falls while working from suspension scaffolds:









Overhead Power Lines The possibility of electrocution is always something to watch out for when working near overhead power lines, and the standard requires specific clearance distances – see 1926.451(f)(6) for a table listing those distances. Scaffolds may be closer to power lines than specified where the clearance is necessary to perform work, but only after the utility company, or electrical system operator, is notified of the need to work closer and they deenergized or relocate the lines, or installed protective coverings to prevent contact with the lines.


Conclusion Scaffolds have provided workers with an ingenious way to work on things when they otherwise “wouldn’t be able to get there from here.” However, as you’ve learned in this course, proper scaffolding is an art that takes practice, training and discipline, not just a “makeshift” climbing mechanism. Be sure you’ve learned the rules from a qualified person and what you’re dealing with and how to do it safely before you head for the top. Scaffold Fact Sheet By definition a scaffold is a temporary, elevated platform that construction workers use for working safely at elevations. There are three basic types of scaffolds: Supported scaffolds are comprised of one or more platforms supported by outrigger beams, brackets, poles, legs, uprights, posts, frames, or similar rigid supports. Suspension scaffolds are comprised of one or more platforms suspended by ropes or other non-rigid means from an overhead structure. Aerial lifts are vehicle-mounted devices such as cherry pickers or boom trucks used to get a worker to an elevated position. The first step in building a scaffold includes a site inspection to:

• Identify site-specific hazards not identified in the preplanning stage, and • Ensure that the specific characteristics of the site are considered in the scaffold

design Meanwhile, erectors should inspect all scaffold parts before use, checking for:

• Cracks • Dents • Bends • Breaks • Corrosion, and/or • Bad welds

on all metal pieces.

The employer shall have each employee who performs work while on a scaffold trained by a person qualified in the subject matter to recognize the hazards associated with the type of scaffold being used and to understand the procedures to control or minimize those hazards. The training shall include the following areas, as applicable:

• The nature of any electrical hazards, fall hazards and falling object hazards in the work area;


• The correct procedures for dealing with electrical hazards and for erecting, maintaining, and disassembling the fall protection systems and falling object protection systems being used;

• The proper use of the scaffold, and the proper handling of materials on the scaffold; and

• The maximum intended load and the load-carrying capacities of the scaffolds used.

The employer also needs to train each employee who is involved in erecting, disassembling, moving, operating, repairing, maintaining, or inspecting a scaffold trained by a competent person to recognize any hazards associated with the work in question. The training shall include the following topics, as applicable:

• The nature of scaffold hazards; • The correct procedures for erecting, disassembling, moving, operating, repairing,

inspecting, and maintaining the type of scaffold in question; • The design criteria, maximum intended load-carrying capacity and intended use

of the scaffold; and • Any other pertinent requirements of this subpart.

Examples of Scaffolding Rules • Workers will use only the installed ladders for access and will never climb a

scaffold using the cross braces or guardrails as ladders • Scaffolds must never be modified by anyone without permission from the

supervisor designated as a “competent person”, including “just removing that brace for a minute to paint behind it....” or doing other seemingly harmless activities

• Any damage to the scaffold has to be reported to the competent person immediately

• Scaffolds cannot be used in high winds or electrical storms; the competent person has the final word on what constitutes these prohibited conditions

• Snow and ice must be cleared from the scaffold before workers attempt to use it If a worker on a scaffold can fall more than 10 feet, they must be protected by guardrails and/or personal fall arrest systems (PFAS). The type of fall protection required will depend upon the type of scaffold being used.

NIOSH recommends the following measures to prevent serious injuries and fatal falls while working from suspension scaffolds:










Module 5 Test Questions 1. Before the start of each work shift, it is mandatory that: a. Someone climb the scaffold and check for loose or missing planks on the platforms b. All scaffold workers don fall arrest systems, hard hats and any other PPE that might be necessary during the course of the work day c. A competent person inspects the scaffold before the start of each work shift d. The work crew has a short meeting discussing the day’s scaffold operations If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/introduction_page_5.html 2. The first step in building a scaffold is to: a. Measure and level the terrain b. Conduct a site inspection c. Build the bottom platform upon which the rest will be erected d. Call all utilities to alert them If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/scaffold_construction_page_2.html 3. A scaffold must be erected “plumb, square, and level,” because: a. It looks better b. It is not possible to build a “plumb, round, and level” scaffold c. It is not practical to build a “plumb, square and tilted” scaffold d. If a scaffold is built even a few degrees off plumb, the resulting instability could cause the weight of the scaffold to shift, potentially causing the overloading of one leg and the eventual collapse of the scaffold. If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/scaffold_construction_page_6.html 4. OSHA 1926.454(c) states: When an employer has reason to believe that an employee lacks the skill or understanding needed for safe work involving the erection, use or dismantling of scaffolds, the employer shall:


a. Fine the employee for coming to work unprepared b. Retrain each such employee so that the requisite proficiency is regained c. Immediately terminate that employee d. Suspend the employee until the employee has re-taken the required courses If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/safe_use_of_scaffolds_page_4.html 5. When dismantling a scaffold, all work should be conducted: a. From the top down b. From as far away as possible to avoid fallout in the event of a collapse c. From the bottom up d. Starting at eye level and then both up and down If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/removing_scaffolds_page_1.html 6. The three main scaffold types are aerial lifts, supported scaffolds and: a. Tubular scaffolds b. Bamboo scaffolds c. Suspended scaffolds d. Rope-ladder scaffolds If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/types_of_scaffolds_page_1.html 7. Tube and coupler scaffolds over 125 feet high must be designed by: a. A competent person b. A sanctified scaffold specialist c. A registered professional engineer d. A certified architect If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/types_of_scaffolds_page_8.html 8. What type of scaffold - other than the tube and coupler scaffold - is ideal for use around complex structures? a. A mobile scaffold b. A system scaffold c. A fabricated metal frame scaffold d. A suspended scaffold


If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/types_of_scaffolds_page_10.html 9. This scaffold is simply a rope attached to a harness with an assembly like a boatswain’s chair for the worker to sit in. a. Suspension scaffold b. System scaffold c. Wood-frame scaffold d. Styrofoam scaffold If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/types_of_scaffolds_page_13.html 10. If a worker on a scaffold can fall more than 10 feet, they must be protected by guardrails and/or personal fall arrest systems (PFAS). The type of fall protection required will depend upon: a. The size of the worker b. The amount of experience the worker has on scaffolds c. The type of scaffold d. The width of the scaffold If the answer you chose was incorrect, read about the correct answer here: http://www.redvector.com/extra/OSHA_safety/mod5NoScorm/scaffold_fall_protection_page_1.html

Scaffold 0c8be2a1 9996-490a-99c0-6ef40baed98a

Business

Transcript of Scaffold 0c8be2a1 9996-490a-99c0-6ef40baed98a