Scaffolds & Temporary Work Platforms
Here at SoCal Removal we have implement a stringent policy to ensure that employees are not exposed to hazards while working on or with scaffolding or elevated work platforms. These injuries account for nearly 50 deaths and thousands of injuries each year in the United States alone. Andre Abajian or SoCal Removals designated competent scaffolding person is responsible for ensuring the following engineering controls, training requirements, and safe work practices are enforced to protect our employees from hazards associated with the erecting, use, and dismantling of scaffolds.
SOCAL DEMOLITION CONTRACTOR RESPONSIBILITIES
Preventing injuries during the setup, use and dismantling of scaffolds is a cooperative effort between the company and its employees.
SoCal Removal Construction Jobsite RESPONSIBILITIES:
- Ensure employees are trained appropriately to their level of responsibility regarding scaffolds
- Acquire appropriate scaffolding for the job to be performed
- Ensure all equipment, including scaffolds, is safe for use by employees
- Ensure there is at least one qualified person at every job that requires scaffolding
QUALIFIED PERSON RESPONSIBILITIES
It is the responsibility of the qualified person to:
- Be competent in fall protection
- Review work plans to determine if scaffolds are necessary
- Design scaffolds to the required specifications
- Ensures the onsite scaffolding meets requirements of the job and all safety guidelines
- Train employees who perform work on scaffolds and work platforms to recognize the hazards specific to that type of work and understand the procedures necessary to control them
It is the responsibility of the competent person to:
- Take prompt measures to eliminate conditions that may pose harm to employees
- Ensure scaffold components from different manufacturers do not intermix
- Evaluate direct connections and to confirm the supporting surfaces are capable of supporting the loads to be imposed on them
- Inspect all suspension scaffold ropes before each shift and after anything that might affect
- a rope’s integrity
- Supervise the erection, moving, dismantling, and altering of scaffolds
SoCal Removal EMPLOYEE RESPONSIBILITIES
All company employees are expected to:
- Complete all requisite training before using scaffolds
- Follow company safety policy and best industry practices
- Perform pre-use inspection before accessing the scaffold
- Report any unsafe condition to the appropriately qualified person
Scaffolds must be constructed and loaded according to the design of a qualified person
Scaffolds and their components must be able to support their own weight and 4 times the maximum intended load. Counterweights used to balance adjustable suspension scaffolds, must be able to resist at least four times the tipping moment imposed by the scaffold operating at either the rated load of the hoist, or one-and-a-half (minimum) times the tipping moment imposed by the scaffold operating at the stall load of the hoist, whichever is greater.
Suspension rope and connecting hardware must be able to support 6 times the maximum intended load of non-adjustable suspension scaffolds.
On adjustable suspension scaffolds, the suspension rope and connecting hardware must support twice the stall load of the hoist if that is greater than 6 times the maximum intended load of the scaffold.
SCAFFOLD PLATFORM CONSTRUCTION
PLANKING AND DECKING
Platforms on working levels of scaffolds must be planked or decked between the front uprights and the guardrail supports so the space between adjacent units and between the platform and uprights is no more than 1 inch wide. Special exception can be made where a wider space is necessary (but never wider than 9½ inches).
Scaffold platforms must be at least 18 inches wide except the following:
- Each ladder jack scaffold, top plate bracket scaffold, roof bracket scaffold, and pump jack scaffold must be at least 12 inches wide
- There is no minimum width requirement for boatswains’ chairs
- Where scaffolds must be used in areas so narrow that platforms and walkways cannot be at least 18 inches wide, these platforms and walkways must be as wide as feasible, and employees on those platforms and walkways must be protected from fall hazards by the use of guardrails and/or personal fall arrest systems
DISTANCE FROM WORK FACE
The front edge of all platforms must be within 14 inches of the face of the work unless guardrail and/or personal fall arrest systems are used to prevent employees from falling, except the following:
- Outrigger scaffolds may be a maximum of 3 inches from the face of work
- For plastering and lathing operations, the maximum distance from the face is 18 inches
ACCESS AND EGRESS
- Instead of the requirements for a stair, fixed ladder, or portable ladder, the intermediate horizontal members of a frame of a manufactured tubular welded frame scaffold may be used for access to, and egress from, the work platform if all of the following conditions are met:
- All frames and component parts are compatible in design
- The intermediate horizontal members of a frame are a minimum of 16 inches in length
- The horizontal members of each frame must be uniformly spaced and must not exceed 17 inches center to center vertically
- When frames connect vertically to one another, the distance between the bottom horizontal member of the upper end frame and the top horizontal member of the lower end frame must be within 3 inches of the uniform spacing of the horizontal members of each frame
- The elevation to the lowest horizontal member of the bottom frame must not exceed 21 inches from ground or floor
- Each horizontal member must be capable of supporting 300 pounds applied at the member’s midpoint without bending or cracking>
- Each horizontal member must be free of cracks, bends, or bad welds
- Only 1 employee at a time may use a horizontal member of a frame as access to, or egress from, the workstation
- Cross braces on tubular welded frame scaffolds must not be used as a means of access or egress
- The guardrail system located on the side where horizontal members of the scaffold frame are used for access to or egress from, a work platform must be constructed as follows:
- The intermediate rail must be omitted between the corner posts at access location
- The top rail must be continuous between posts
- Each end of a platform must extend over the centerline of its support by at least 6 inches unless it is cleated, or restrained by hooks or equivalent means
- A platform 10 feet or less may not extend over its support more than 12 inches unless it is designed not to tip when supporting weight or has guardrails to block access
- A platform more than 10 feet in length may not extend over its support more than 18 inches unless it is designed not to tip when supporting weight or has guardrails to block access
- Where scaffold planks abut one another to create a long platform, they should only overlap over supports by more than 12 inches unless they are nailed together or otherwise restrained
- Where the platform changes direction, as around a corner, lay platforms off right angles first and platforms that rest at right angles second
- Construction and attachment of a scaffold must not cause a direct pull on the fasteners
- Do not cover wood platforms with opaque finishes (platform edges may be covered or marked for identification). Platforms may be coated periodically with wood preservatives, fire-retardant finishes, and slip-resistant finishes, but the coating may not obscure the top or bottom wood surfaces
- Scaffolding endangered by a truck or other moving equipment must be protected by a warning device, or barrier, or both
- Scaffold components from different manufacturers must not be intermixed unless the components fit together without force and the scaffold’s structural integrity is maintained by the user. Do not modify scaffold components by different manufacturers to intermix them unless a competent person determines the resulting scaffold is structurally sound
- Components of different metals may not be used together unless a competent person can confirm that galvanic action will not reduce their strengths
CRITERIA FOR SUPPORTED SCAFFOLDS
Supported scaffolds with a height to base width ratio of more than four to one (4:1) must be restrained from tipping by guying, tying, bracing, or equivalent means, as follows:
- Guys, ties, and braces must be installed at locations where horizontal members support both inner and outer legs
- Guys, ties, and braces must be installed according to the scaffold manufacturer’s recommendations or at the closest horizontal member to the 4:1 height and be repeated vertically at locations of horizontal members every 20 feet or less thereafter for scaffolds 3 feet wide or less, and every 26 feet or less thereafter for scaffolds greater than 3 feet wide
- The top guy, tie, or brace of completed scaffolds must be placed no further than the 4:1 height from the top. Such guys, ties and braces must be installed at each end of the scaffold and at horizontal intervals not to exceed 30 feet (measured from one end to the other, not both ends to the center)
- Ties, guys, braces, or outriggers must be used to prevent the tipping of supported scaffolds in all circumstances where an eccentric load, such as a cantilevered work platform, is applied or is transmitted to the scaffold
- Supported scaffold poles, legs, posts, frames, and uprights must bear on adequate firm foundation
- Footings must be level, sound, rigid, and capable of supporting the loaded scaffold without settling or displacement
- Scaffolds may not be supported with unstable objects
- Unstable objects must not be used as working platforms
- Do not use front-end loaders and similar pieces of equipment to support scaffold platforms unless they have been specifically designed by the manufacturer for such use
- Do not use forklifts to support scaffold platforms unless the entire platform is attached to the fork and the forklift is not moved horizontally while the platform is occupied
- Brace and plumb supported scaffold poles, legs, posts, frames, and uprights to prevent swaying and displacement
ERECTION & DISMANTLING
- A safe means of access must be provided for employees erecting or dismantling a scaffold where the provision of safe access is feasible and does not create a greater hazard. A competent person will determine whether it is feasible or would pose a greater hazard to provide, and have employees use a safe means of access. This determination must be based on site conditions and the type of scaffold being erected or dismantled
- Hook-on or attachable ladders must be installed as soon as scaffold erection has progressed to a point that permits their safe installation and use
- When erecting or dismantling tubular welded frame scaffolds, (end) frames, with horizontal members that are parallel, level, and are not more than 22 inches apart vertically may be used as climbing devices for access, provided they are erected in a manner that creates a usable ladder and provides good hand hold and foot space
CRITERIA FOR SUSPENSION SCAFFOLDS
All suspension scaffold support devices must rest on surfaces capable of supporting at least 50 lbs/ft2 and 4 times the load imposed on them by the scaffold operating at the rated load of the hoist (or at least 1.5 times the load imposed on them by the scaffold at the stall capacity of the hoist, whichever is greater).
Before the scaffold is used, direct connections must be evaluated by a competent person who can confirm supporting surfaces are capable of supporting the loads to be imposed.
A bearer for a suspension scaffold must be made of 4 x 6-inch timber set on edge or structural steel of equivalent strength. A bearer must have sufficient length to hold the planks between the frames where a hoisting machine is used. Plank edges must abut.
The connections of a masons’ multi-point adjustable suspension scaffold must be designed by an engineer experienced in such scaffold design.
- Use counterweights made of non-flowable material. Sand, gravel, and similar materials can easily be dislocated and must not be used as counterweights
- Use items specifically designed as counterweights to secure scaffold systems.
- Construction materials such as, but not limited to, masonry units and rolls of roofing felt, must not be used as counterweights
- Secure counterweights by mechanical means to the outrigger beams to prevent accidental displacement
- Do not remove counterweights from an outrigger beam until the scaffold is disassembled
Suspension scaffold outrigger beams, when used, must be made of structural metal or equivalent strength material, and be restrained to prevent movement.
Stabilize the inboard ends of suspension scaffold outrigger beams with bolts or other direct connections to the floor or roof deck, or by counterweights. (Masons’ multi-point adjustable suspension scaffold outrigger beams may not be stabilized by counterweights.)
Place outrigger beams perpendicular to bearing support (usually the face of the building or structure). However, where the employer can demonstrate that it is not possible to place an outrigger beam perpendicular to the face of the building or structure because of obstructions that cannot be moved, the outrigger beam may be placed at some other angle, provided opposing angle tiebacks are used.
Suspension scaffold outrigger beams must be:
- Provided with stop bolts or shackles at both ends
- Securely fastened together with the flanges turned out when channel iron beams are used in place of I-beams
- Installed with all bearing supports perpendicular to the center line of the beam
- Set and maintained with the web in a vertical position
- When an outrigger beam is used, the shackle or clevis that attaches the rope to the outrigger beam must be placed directly over the centerline of the stirrup
Outrigger beams not stabilized by bolts or other direct connections to the floor or roof deck must be secured by tiebacks.
Tiebacks must be equivalent in strength to the suspension ropes and secured to a structurally sound anchorage on the building or structure. Sound anchorages include structural members, but not piping systems, vents, or electrical conduit
Install tiebacks perpendicular to the face of the building or structure, or install opposing angle tiebacks. Single tiebacks installed at an angle are prohibited
Tiebacks must be equivalent in strength to the hoisting rope
Suspension scaffold support devices such as cornice hooks, roof hooks, roof irons, parapet clamps, or similar devices must be:
- Made of steel, wrought iron, or materials of equivalent strength
- Supported by bearing blocks
- Secured against movement by tiebacks installed at right angles to the face of the building or structure. If opposing angle tiebacks are used, they must be installed and secured to a structurally sound anchorage point on the building or structure. Sound points of anchorage include structural members, but do not include standpipes, vents, other piping systems, or electrical conduit
HOISTS & ROPES
When winding drum hoists are used on a suspension scaffold, they must contain at least four wraps of the suspension rope at the lowest point of scaffold travel. When other types of hoists are used, the suspension ropes must be long enough to allow the scaffold to be lowered to the level below without the rope end passing through the hoist, or the rope end must be configured or provided with means to prevent the end from passing through the hoist.
Do not use repaired wire rope as suspension rope, and do not join them together except with eye splice thimbles connected with shackles or cover plates.
Equip the load end of wire suspension ropes with proper size thimbles and secure them by eye splicing or equivalent means.
Ropes must be inspected for defects by a competent person before each work shift and after occurrences that could affect a rope’s integrity. Ropes must be replaced if any of the following conditions exist:
- Physical damage that impairs the function and strength of the rope
- Kinks that might impair the tracking or wrapping of rope around the drum(s) or sheave(s)
- Six randomly distributed broken wires in one rope lay or three broken wires in one strand in one rope lay
- Abrasion, corrosion, scrubbing, flattening or peening causing loss of more than one-third of the original diameter of the outside wires
- Heat damage from a torch or damage caused by contact with electrical wires
- Evidence that the secondary brake has been activated during an overspeed condition and has engaged the suspension rope
Swaged attachments or spliced eyes on wire suspension ropes must not be used unless they are made by the wire rope manufacturer or a qualified person.
When wire rope clips are used on suspension scaffolds:
- There must be at least 3 wire rope clips installed, each a minimum of 6 rope diameters apart
- Install clips according to the manufacturer’s recommendations
- Retighten clips to the manufacturer’s recommendations after the initial loading
- Inspect clips and retighten them to the manufacturer’s recommendations at the start of each work shift thereafter
- U-bolt clips must not be used at the point of suspension for any scaffold hoist
- When U-bolt clips are used, the U-bolt must be placed over the dead end of the rope, and the saddle must be placed over the live end of the rope
- Suspension scaffold power-operated hoists and manual hoists must be tested by a qualified testing laboratory
- Do not use gasoline-powered equipment and hoists on suspension scaffolds
- Enclose gears and brakes of power-operated hoists used on suspension scaffolds
- In addition to the normal operating brake, suspension scaffold power-operated hoists and manually operated hoists must have a braking device or locking pawl that engages automatically when a hoist makes an instantaneous change in momentum or an accelerated overspeed
- Manually operated hoists must require a positive crank force to descend
- Two-point and multi-point suspension scaffolds must be secured to prevent them from swaying, as determined to be necessary based on an evaluation by a competent person. Window cleaners’ anchors must not be used for this purpose
- Devices whose sole function is to provide emergency escape and rescue must not be used as working platforms. This provision does not preclude the use of systems that are designed to function both as suspension scaffolds and emergency systems
ACCESS TO ALL SCAFFOLDS
When scaffold platforms are more than 2 feet above or below a point of access, portable ladders, hook-on ladders, attachable ladders, stair towers (scaffold stairways/towers), stairway- type ladders, ramps, walkways, integral pre-fabricated scaffold access, or direct access from another scaffold, structure, personnel hoist, or similar surface must be used. Do not use crossbraces as a means of access.
In addition to requirements outlined in the chapter on ladder safety, portable, hook-on, and attachable ladders must adhere to the following criteria:
- Position portable, hook-on, and attachable ladders so as not to tip the scaffold
- Position hook-on and attachable ladders so their bottom rung is not more than 24 inches above the scaffold supporting level
- When hook-on and attachable ladders are used on a supported scaffold more than 35 feet high, they must have rest platforms at 35-foot maximum vertical intervals.
- Hook-on and attachable ladders must be designed for the type of scaffold being used
- Hook-on and attachable ladders must have a minimum rung length of 11½”
- Hook-on and attachable ladders must have uniformly spaced rungs with a maximum spacing between rungs of 16¾ inches
STAIRWAY-TYPE LADDERS MUST:
- Be positioned such that their bottom step is not more than 24 inches above the scaffold supporting level
- Be provided with rest platforms at 12 foot maximum vertical intervals
- Have a minimum step width of 16 inches, except that mobile scaffold stairway-type ladders must have a minimum step width of 11½ inches
- Have slip-resistant treads on all steps and landings
- Stair towers (scaffold stairway/towers) must be placed so that their bottom step is not more than 24 inches above the scaffold supporting level.
- A stair rail consisting of a toprail and a midrail must be provided on each side of each scaffold stairway.
- The toprail of each stair rail system must also be capable of serving as a handrail, unless a separate handrail is provided.
- Handrails, and toprails that serve as handrails, must provide an adequate handhold for employees grasping them to avoid falling.
- Stair rail systems and handrails must be surfaced to prevent injury to employees from punctures or lacerations, and to prevent snagging of clothing.
- The ends of stair rail systems and handrails must be constructed so that they do not constitute a projection hazard.
- Handrails, and toprails used as handrails, must be at least 3 inches from other objects
- Stair rails must be at least 28 inches but not more than 37 inches from the upper surface of the stair rail to the surface of the tread, in line with the face of the riser at the forward edge of the tread.
- A landing platform at least 18 inches wide and 18 inches long must be provided at each level.
- Each scaffold stairway must be at least 18 inches wide between stair rails.
- Treads and landings must have slip-resistant surfaces.
- Stairways must be installed between 40 degrees and 60 degrees from the horizontal.
- Guardrails meeting safety requirements must be installed on the open sides and ends of each landing.
- Riser height must be uniform, within ¼ inch, for each flight of stairs. Greater variations in riser height are allowed for the top and bottom steps of the entire system, not for each flight of stairs.
- Tread depth must be uniform, within ¼ inch, for each flight of stairs.
RAMPS & WALKWAYS
- Ramps and walkways 6 feet or more above lower levels must have guardrail systems that comply with fall protection regulations.
- No ramp or walkway must be inclined more than a slope of one vertical to three horizontal (20 degrees above the horizontal).
- If the slope of a ramp or a walkway is steeper than one vertical in eight horizontal, the ramp or walkway must have cleats not more than fourteen inches apart that are securely fastened to the planks to provide footing.
Integral prefabricated scaffold access frames must:
- Be specifically designed and constructed for use as ladder rungs
- Have a rung length of at least 8 inches
- Not be used as work platforms when rungs are less than 11½ inches in length, unless each affected employee uses fall protection, or a positioning device
- Be uniformly spaced within each frame section
- Be provided with rest platforms at 35-foot maximum vertical intervals on all supported scaffolds more than 35 feet high
- Have a maximum spacing between rungs of 16¾ inches. Non-uniform rung spacing caused by joining end frames together is allowed, provided the resulting spacing does not exceed 16¾ inches
Steps and rungs of ladder and stairway type access must line up vertically with each other between rest platforms.
Direct access to or from another surface must be used only when the scaffold is not more than 14 inches horizontally and not more than 24 inches vertically from the other surface.
USE OF SCAFFOLDS
- Never load scaffolds or their components in excess of their maximum intended loads or rated capacities, whichever is less.
- Do not use shore or lean-to scaffolds.
- A competent person must inspect scaffolds and scaffold components for visible defects before use and after any occurrence that could affect a scaffold’s structural integrity.
- Any part of a scaffold that is damaged or weakened resulting in a reduction of the structure’s strength, must be immediately repaired or replaced, braced to meet those provisions, or removed from service until repaired.
- Unless a registered professional engineer designed the scaffolds specifically for movement, no scaffold may be moved horizontally while employees are on them.
- No scaffold may be erected, used, dismantled, altered, or moved if any conductive material handled on them might come closer to exposed and energized power lines than indicated in Table 1.
- Scaffolds may be closer than specified after the utility company or electrical system operator has been notified, has de-energized the lines, or installed protective coverings to prevent accidental contact.
- Only experienced and trained employees will erect, move or dismantle scaffolds, and only under the supervision and direction of a competent person.
- Employees may not work on scaffolds covered in slippery material like ice or snow (except as needed to remove it).
LADDER SAFETY ON SCAFFOLDS
Employees may not increase the working level on top of scaffold platforms with makeshift devices like boxes or barrels.
Ladders also may not be used to increase the working level height of an employee unless the following criteria are met:
- When the ladder is placed against a structure which is not a part of the scaffold, the scaffold must be secured against the sideways thrust exerted by the ladder
- The platform units must be secured to the scaffold to prevent their movement
- The ladder legs must be on the same platform or other means must be provided to stabilize the ladder against unequal platform deflection
- The ladder legs must be secured to prevent them from slipping or being pushed off the platform
WELDING SAFETY ON SCAFFOLDS
To reduce the possibility of welding current arcing through the suspension wire rope when performing welding from suspended scaffolds, the following precautions must be taken, as applicable:
- An insulated thimble must be used to attach each suspension wire rope to its hanging support (such as cornice hook or outrigger). Excess suspension wire rope and any additional independent lines that is in contact with the scaffold must be insulated
- The suspension wire rope must be covered with insulating material extending at least 4 feet above the hoist. If there is a tail line below the hoist, it must be insulated to prevent contact with the platform. The portion of the tail line that hangs free below the scaffold must be guided or retained, or both, so that it does not become grounded
- Each hoist must be covered with insulated protective covers
- In addition to a work lead attachment required by the welding process, a grounding conductor must be connected from the scaffold to the structure. The size of this conductor must be at least the size of the welding process work lead, and this conductor must not be in series with the welding process or the work piece
- If the scaffold grounding lead is disconnected at any time, the welding machine must be shut off
- An active welding rod or uninsulated welding lead must not be allowed to contact the scaffold or its suspension system
Fall protection must be provided to employees working on a scaffold more than 10 feet above a lower level to prevent falls to that lower level. See Table 2.
FALL PROTECTION BY TYPE OF SCAFFOLD
- Each employee on a boatswains’ chair, catenary scaffold, float scaffold, needle beam scaffold, or ladder jack scaffold must be protected by a personal fall arrest system.
- Each employee on a crawling board (chicken ladder) must be protected by a personal fall arrest system, a guardrail system (with minimum 200 pound toprail capacity), or by a three-fourth inch diameter grabline or equivalent handhold securely fastened beside each crawling board.
- A lifeline and safety belt must be used where an employee is required to crawl out on a thrustout or projecting beam.
- Each employee on a self-contained adjustable scaffold must be protected by a guardrail system (with minimum 200 pound toprail capacity) when the platform is supported by the frame structure, and by both a personal fall arrest system and a guardrail system (with minimum 200 pound toprail capacity) when the platform is supported by ropes.
- Each employee on a walkway located within a scaffold must be protected by a guardrail system (with minimum 200 pound toprail capacity) installed within 9½ inches (24.1 cm) of and along at least one side of the walkway.
- Each employee performing overhand bricklaying operations from a supported scaffold must be protected from falling from all open sides and ends of the scaffold (except at the side next to the wall being laid) by the use of a personal fall arrest system or guardrail system (with minimum 200 pound toprail capacity).
For all scaffolds not otherwise specified, each employee must be protected by the use of personal fall arrest systems or guardrail systems meeting all safety requirements.
FALL PROTECTION FOR SCAFFOLD ERECTORS AND DISMANTLERS
SoCal Removal will have a competent person determine the feasibility and safety of providing fall protection for employees erecting or dismantling supported scaffolds, and will provide fall protection for employees erecting or dismantling supported scaffolds where the installation and use of such protection is feasible and does not create a greater hazard.
Personal fall arrest systems used on scaffolds will follow all safety regulations and policy for fall protection and will be attached by lanyard to a vertical lifeline, horizontal lifeline, or scaffold structural member.
Vertical lifelines must not be used when overhead components, such as overhead protection or additional platform levels, are part of a single-point or two- point adjustable suspension scaffold.
When vertical lifelines are used, they must be fastened to a fixed safe point of anchorage, must be independent of the scaffold, and must be protected from sharp edges and abrasion. Safe points of anchorage include structural members of buildings, but do not include standpipes, vents, other piping systems, electrical conduit, outrigger beams, or counterweights.
When horizontal lifelines are used, they must be secured to two or more structural members of the scaffold, or they may be looped around both suspension and independent suspension lines (on scaffolds so equipped) above the hoist and brake attached to the end of the scaffold. Horizontal lifelines must not be attached only to the suspension ropes.
When lanyards are connected to horizontal lifelines or structural members on a single-point or two-point adjustable suspension scaffold, the scaffold must be equipped with additional independent support lines and automatic locking devices capable of stopping the fall of the scaffold in the event one or both of the suspension ropes fail. The independent support lines must be equal in number and strength to the suspension ropes.
Vertical lifelines, independent support lines, and suspension ropes must not be attached to each other, or attached to or use the same point of anchorage, nor can they be attached to the same point on the scaffold or personal fall arrest system.
Guardrail systems must comply with the following provisions:
- Guardrail systems must be installed along all open sides and ends of platforms
- Guardrail systems must be installed before employees, other than erection/dismantling crews, can use the scaffold
- The top edge height of toprails or equivalent members on supported scaffolds manufactured or placed in service after Jan. 1, 2000 must be installed between 38 inches and 45 inches above the platform surface.
- The top edge height on supported scaffolds manufactured and placed in service before Jan. 1, 2000, and on all suspended scaffolds where both a guardrail and a personal fall arrest system are required, must be between 36 inches and 45 inches. When conditions warrant, the height of the top edge may exceed the 45-inch height, provided the guardrail system meets all other criteria
- When midrails, screens, mesh, intermediate vertical members, solid panels, or equivalent structural members are used, they must be installed between the top edge of the guardrail system and the scaffold platform
- When midrails are used, they must be installed at a height approximately midway between the top edge of the guardrail system and the platform surface
- When screens and mesh are used, they must extend from the top edge of the guardrail system to the scaffold platform, and along the entire opening between the supports
- When intermediate members (such as balusters or additional rails) are used, they must not be more than 19 inches apart
- Each toprail or equivalent member of a guardrail system must be capable of withstanding, without failure, a force applied in any downward or horizontal direction at any point along its top edge of at least 100 pounds for guardrail systems installed on single-point adjustable suspension scaffolds or two-point adjustable suspension scaffolds, and at least 200 pounds for guardrail systems installed on all other scaffolds
- When the loads are applied in a downward direction, the top edge must not drop below the height above the platform surface
- Midrails, screens, mesh, intermediate vertical members, solid panels, and equivalent structural members of a guardrail system must be capable of withstanding, without failure, a force applied in any downward or horizontal direction at any point along the midrail or other member of at least 75 pounds for guardrail systems with a minimum 100-pound toprail capacity, and at least 150 pounds (666 n) for guardrail systems with a minimum 200-pound toprail capacity
- Suspension scaffold hoists and non-walk-through stirrups may be used as end guardrails, if the space between the hoist or stirrup and the side guardrail or structure does not allow passage of an employee to the end of the scaffold
- Guardrails must be surfaced to prevent injury to an employee from punctures or lacerations, and to prevent snagging of clothing
- The ends of all rails must not overhang the terminal posts except when such overhang does not constitute a projection hazard to employees
- Steel or plastic banding must not be used as a toprail or midrail
- Manila or plastic (or other synthetic) rope being used for toprails or midrails must be inspected by a competent person as frequently as necessary to ensure that it continues to meet strength requirements
- Crossbracing 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 or as a toprail when the crossing point of two braces 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
FALLING OBJECT PROTECTION
Where there is a danger of tools, materials, or equipment falling from a scaffold and striking employees below, the following provisions apply:
- The area below the scaffold to which objects can fall must be barricaded, and employees must not be permitted to enter the hazard area
- A toeboard must be erected along the edge of platforms more than 10 feet above lower levels for a distance sufficient to protect employees below, except on float (ship) scaffolds where an edging of ¾ x 1 ½ inch wood or equivalent may be used in lieu of toeboards
- Where tools, materials, or equipment are piled to a height higher than the top edge of the toeboard, paneling or screening extending from the toeboard or platform to the top of the guardrail must be erected for a distance sufficient to protect employees below
- A guardrail system must be installed with openings small enough to prevent passage of potential falling objects
A canopy structure, debris net, or catch platform strong enough to withstand the impact forces of the potential falling objects must be erected over the employees below. Canopies, when used for falling object protection, must comply with the following criteria:
- Canopies must be installed between the falling object hazard and the employees
- When canopies are used on suspension scaffolds for falling object protection, the scaffold must be equipped with additional independent support lines equal in number to the number of points supported, and equivalent in strength to the strength of the suspension ropes
- Independent support lines and suspension ropes must not be attached to the same points of anchorage
Where used, toeboards must be:
- Capable of withstanding, without failure, a force of at least 50 pounds applied in any downward or horizontal direction at any point along the toeboard
- At least three and one-half inches high from the top edge of the toeboard to the level of the walking/working surface.
- Toeboards must be securely fastened in place at the outermost edge of the platform and not have more than ¼ inch clearance above the walking/working surface
- Toeboards must be solid or with openings not over one inch in the greatest dimension
REQUIREMENTS FOR SCAFFOLDS
The specifications outlined in this section assume all load-carrying timber members of the scaffold are a minimum of 1,500 lb/in2 construction grade lumber.
Allowable spans must comply with the National Design Specification for Wood Construction published by the National Forest Products Association; paragraph 5 of American National Standards Institute (ANSI) A10.8-1988 Scaffolding-Safety Requirements; or for 2×10-inch (nominal) or 2×9-inch (rough) solid sawn wood planks, as shown in Table 3.
The maximum permissible span for 1¼ x 9-inch or wider wood plank of full thickness with a maximum intended load of 50 lb/ft2 must be 4 feet.
- Fabricated planks and platforms may be used instead of wood. Maximum spans for such units must be as recommended by the manufacturer based on the maximum intended load being calculated as described in the table chart.
Single-pole scaffolding must:
- Have the inner end of the bearer rest in the wall of the building with at least a 4-inch bearing. Notching is prohibited
- Have the inner end of the bearer, when used on frame buildings, rest on a block 12 inches long and not less than 2 inches by 6 inches nominal size. The block must be notched the width of the bearer and not less than 2 inches deep. The bearer must be nailed to both the block and the building
- Diagonal bracing in both directions must be installed across the entire outside face of all double- and single-pole scaffolds. Diagonal bracing in both directions must be installed across the entire inside face of double-pole scaffolds used to support loads equivalent to a uniformly distributed load of 50 pounds or more per square foot
- Braces, bearers, and runners (ledgers) must not be spliced between poles. When a wood pole is spliced, the ends should be square and flat. Not less than 2 wood splice plates should be secured to adjacent sides and should be not less than 4 feet in length by 1 inch thick by the same width as the pole and have equal overlap to the joint. More than 1 consecutive splice per general level must not be made (see the figure at right)
- Two runners meeting at a pole must be nailed to each other, and 2 ledgers meeting at a corner must have 1 cut flush to the pole and the other nailed on the outside and overlap
- Runners must extend over a minimum of two poles, and must be supported by bearing blocks securely attached to the poles
- Runners must overlap the poles at each end by not less than 4 inches, be level, and be nailed to the inside of the poles. A runner must not be nailed less than 1 inch to the top edge
- A spliced runner must be reinforced by a bearing block secured to the side of the pole to form a support for the runner
- Runners and bearers must be installed on edge
- A bearer must be set with its greater dimension vertical and must project 3 inches beyond
- Pole scaffolds over 60 feet in height must be designed by a registered professional engineer, and must be constructed and loaded in accordance with that design of the runner and the inner and outer pole
- Successive lengths of planking must not abut on a single bearer and, where planks abut, 2 bearers must be placed not more than 8 inches apart
- When moving a work platform to a new level, the old platform must remain in place until the new bearers are in place to receive the platform
- A wood pole scaffold must not be erected beyond the reach of fire-fighting equipment
Metal TANK Demolition SCAFFOLDS
- The maximum distance between brackets to which scaffolding and guardrail supports are attached must be no more than 10 feet 6 inches.
- Not more than three employees can occupy a 10 feet 6 inch span of scaffold planking at any time.
- A taut wire or synthetic rope supported on the scaffold brackets must be installed at the scaffold plank level between the innermost edge of the scaffold platform and the curved plate structure of the tank shell to serve as a safety line in lieu of an inner guardrail assembly where the space between the scaffold platform and the tank exceeds 12 inches. In the event the open space on either side of the rope exceeds 12 inches, a second wire or synthetic rope appropriately placed, or guardrails in accordance with regulations, must be installed in order to reduce that open space to less than 12 inches.
- Scaffold planks of rough full-dimensioned 2-inch x 12-inch Douglas Fir or Southern Yellow Pine of Select Structural Grade must be used. Douglas fir planks must have a fiber stress of at least 1900 lb/in2 and a modulus of elasticity of at least 1,900,000 lb/in2, while Yellow Pine planks must have a fiber stress of at least 2500 lb/in2 and a modulus of elasticity of at least 2,000,000 lb/in2.
Guardrails must be constructed of a taut wire or synthetic rope, and must be supported by angle irons attached to brackets welded to the steel plates. Guardrail supports must be located at no greater than 10 feet 6 inch intervals.
Guardrails must be as follows:
- Toprails must be equivalent in strength to 2 inch by 4 inch lumber; or 1¼ inch x ⅛ inch structural angle iron; or 1 inch x .070 inch wall steel tubing; or 1.990 inch x .058 inch wall aluminum tubing
- Midrails must be equivalent in strength to 1 inch by 6 inch lumber; or 1¼ inch x 1¼ inch x ⅛ inch structural angle iron; or 1 inch x .070 inch wall steel tubing; or 1.990 inch x .058 inch wall aluminum tubing
- Toeboards must be equivalent in strength to 1 inch by 4 inch lumber; or 1 ¼ inch x 1 ¼ inch structural angle iron; or 1 inch x .070 inch wall steel tubing; or 1.990 inch x .058 inch wall aluminum tubing
- Posts must be equivalent in strength to 2 inch by 4 inch lumber; or 1 ¼ inch x 1 ¼ inch x ⅛ structural angle iron; or 1 inch x .070 inch wall steel tubing; or 1.990 inch x .058 inch wall aluminum tubing
- Distance between posts must not exceed 8 feet