Scaffolds Scaffolds These handouts and documents with attachments are not final, complete, or definitive instruments. This information These handouts and documents with attachments are not final, complete, or definitive instruments. This information is for guidance purposes only. You should independently verify and satisfy yourself as to its accuracy. The is for guidance purposes only. You should independently verify and satisfy yourself as to its accuracy. The AHBSIF does not assume any liability for damages arising from the use of this information or exhibits and AHBSIF does not assume any liability for damages arising from the use of this information or exhibits and attachments thereto and renders no opinion that any of the terms, conditions, and/or cited federal standards in attachments thereto and renders no opinion that any of the terms, conditions, and/or cited federal standards in this document and the exhibits and attachments should be explicitly followed by the fund member. Seek specific this document and the exhibits and attachments should be explicitly followed by the fund member. Seek specific guidance from the appropriate regulator (OSHA) or professional advisor. guidance from the appropriate regulator (OSHA) or professional advisor.
Transcript
ScaffoldsScaffolds
These handouts and documents with attachments are not final, complete, or definitive instruments. This information is for guidance These handouts and documents with attachments are not final, complete, or definitive instruments. This information is for guidance purposes only. You should independently verify and satisfy yourself as to its accuracy. The AHBSIF does not assume any purposes only. You should independently verify and satisfy yourself as to its accuracy. The AHBSIF does not assume any
liability for damages arising from the use of this information or exhibits and attachments thereto and renders no opinion that liability for damages arising from the use of this information or exhibits and attachments thereto and renders no opinion that any of the terms, conditions, and/or cited federal standards in this document and the exhibits and attachments should be any of the terms, conditions, and/or cited federal standards in this document and the exhibits and attachments should be
explicitly followed by the fund member. Seek specific guidance from the appropriate regulator (OSHA) or professional advisor.explicitly followed by the fund member. Seek specific guidance from the appropriate regulator (OSHA) or professional advisor.
Introduction to ScaffoldsIntroduction to Scaffolds OSHA revised the OSHA revised the
scaffold standard in scaffold standard in 1997 due to the 1997 due to the following;following; A quarter of the workers A quarter of the workers
responsible for installing responsible for installing work platforms and work platforms and inspecting, and inspecting, and assembling them had no assembling them had no formal training.formal training.
Only 1/3 of scaffolds were Only 1/3 of scaffolds were equipped with handrails.equipped with handrails.
Defining a Competent Defining a Competent PersonPerson
One who is capable of identifying existing One who is capable of identifying existing and predictable hazards in the and predictable hazards in the surroundings, or working conditions which surroundings, or working conditions which are unsanitary, hazardous, or dangerous are unsanitary, hazardous, or dangerous to employees, and who has to employees, and who has authorization authorization to eliminateto eliminate them. them.
Scaffolds Scaffolds shall beshall be constructed, altered, constructed, altered, or dismantledor dismantled under the supervision of a under the supervision of a competent person.competent person.
General RequirementsGeneral Requirements All scaffolds must be inspected prior to All scaffolds must be inspected prior to
use.use. 10’ is the point at which some means of 10’ is the point at which some means of
fall protection must be used.fall protection must be used. Top handrails should be around 42”, with Top handrails should be around 42”, with
the mid-rail about half way at 21”.the mid-rail about half way at 21”. Toe boards or other adequate means of Toe boards or other adequate means of
falling object protection must be installed if falling object protection must be installed if there is a possibility of anything falling and there is a possibility of anything falling and striking someone below.striking someone below.
General RequirementsGeneral Requirements All scaffolds must All scaffolds must
support their own support their own weight and 4x the weight and 4x the maximum intended maximum intended load.load.
Vertical tie-in or outrigger Vertical tie-in or outrigger support is not necessary support is not necessary on a free-standing scaffold on a free-standing scaffold until the height exceeds until the height exceeds the minimum dimension the minimum dimension of the base by four times.of the base by four times.
General RequirementsGeneral Requirements
Ladder use on a Ladder use on a scaffold is scaffold is prohibited.prohibited.
Platforms must be Platforms must be kept clear of debris.kept clear of debris.
Do not load side Do not load side brackets. Most are brackets. Most are rated at 25 lbs/ft² rated at 25 lbs/ft² maximum.maximum.
Decks And PlankingDecks And Planking All platforms must be fully decked or planked.All platforms must be fully decked or planked. Each abutted end of a plank shall rest on a separate Each abutted end of a plank shall rest on a separate
support surface.support surface. Overlap platforms not less than 12” only over supports, Overlap platforms not less than 12” only over supports,
unless restrained to prevent movement, i.e. ”Cleating”.unless restrained to prevent movement, i.e. ”Cleating”. The working deck should never be more than 14” away The working deck should never be more than 14” away
from the working surface.from the working surface.
Decks And PlankingDecks And Planking A scaffold grade plank will A scaffold grade plank will
be stamped or marked as be stamped or marked as suchsuch
Plank must be laminated or Plank must be laminated or solid drawnsolid drawn
A lumber yard 2 x 10 can be A lumber yard 2 x 10 can be used if it is free of knots or used if it is free of knots or other defectsother defects
Rough Sawn, Full Rough Sawn, Full Dimension LumberDimension Lumber
Nominal Thickness LumberNominal Thickness Lumber
Working Working Load in Load in lbs/ft²lbs/ft²
2525 5050 7575 2525 5050 7575
Permissible Permissible Span in FeetSpan in Feet 1010 88 66 88 66 66
Overhead Power LinesOverhead Power Lines The clearance between scaffolds and The clearance between scaffolds and
power lines is as follows:power lines is as follows:
> 50 kV> 50 kV 10’ + 1/2”10’ + 1/2” for every for every additional kVadditional kV
Frame ScaffoldsFrame Scaffolds
Systems should use only Systems should use only original parts. Components original parts. Components from different systems from different systems should not be mixed.should not be mixed.
All frame scaffolds must use All frame scaffolds must use a manufactured base pad. a manufactured base pad. Vertical tubes should never Vertical tubes should never sit directly on the ground or sit directly on the ground or make-shift mud sill.make-shift mud sill.
X-braces may serve as a top-X-braces may serve as a top-rail or mid-rail, but not both.rail or mid-rail, but not both.
If aluminum walking decks If aluminum walking decks are used, be sure that end are used, be sure that end hooks are in place and that hooks are in place and that the dimensions match the the dimensions match the scaffold.scaffold.
Frame Scaffolds - AccessFrame Scaffolds - Access Erectors can climb either Erectors can climb either
type, but provisions for type, but provisions for safe access should be safe access should be established as soon as established as soon as possible.possible.
Bottom rung cannot be Bottom rung cannot be more than two feet high.more than two feet high.
Options for access are Options for access are manufactured bolt-on manufactured bolt-on ladder system, stair ladder system, stair system, or extension ladder system, or extension ladder secured and sloped secured and sloped properly.properly.
X-braces are not intended X-braces are not intended for use as access.for use as access.
““Stick-Built” Pole ScaffoldStick-Built” Pole Scaffold 2” x 4” poles free of knots, splits or other defects.2” x 4” poles free of knots, splits or other defects. 1” x 4” cross-bracing for each section.1” x 4” cross-bracing for each section. 2” x 6” or 2” x 8” block under pole if soft ground.2” x 6” or 2” x 8” block under pole if soft ground. Walk board a Walk board a minimumminimum 2” x 10” free of knots or other defects. 2” x 10” free of knots or other defects. Walk boards must hang over bearer a minimum of 6”.Walk boards Walk boards must hang over bearer a minimum of 6”.Walk boards
must overlap each other a minimum of 12”.must overlap each other a minimum of 12”. 2” x 4” top rail, mid rail, and toe board 2” x 4” top rail, mid rail, and toe board
Stick Built ScaffoldsStick Built Scaffolds
Proper Proper overlap on overlap on deck plankingdeck planking
Top rail and Top rail and mid rail mid rail established established after deck after deck height height reaches ten reaches ten feetfeet
Adequate Adequate support support between between stanchionsstanchions
Proper mud Proper mud sills under sills under polespoles
Is this scaffold Is this scaffold complete?complete?
Pump Jack ScaffoldsPump Jack Scaffolds
Pump Jack brackets, Pump Jack brackets, braces, and accessories braces, and accessories must be fabricated from must be fabricated from metal.metal.
Each pump jack bracket Each pump jack bracket must have two positive must have two positive gripping mechanisms.gripping mechanisms.
Poles should be secured to Poles should be secured to the structure with the structure with triangular bracing.triangular bracing.
Work benches should not Work benches should not be used as a working deck.be used as a working deck.
If 2x4’s are spliced to make If 2x4’s are spliced to make a pole, mending plates a pole, mending plates must be installed to must be installed to maintain strength. maintain strength.
Ladder Jack ScaffoldsLadder Jack Scaffolds
Platforms must not exceed Platforms must not exceed 20’ in height.20’ in height.
Job made ladders cannot be Job made ladders cannot be used to support ladder jack used to support ladder jack scaffolds.scaffolds.
Ladders that support ladder Ladders that support ladder jacks must be placed, jacks must be placed, fastened, or equipped with fastened, or equipped with devices to prevent slipping.devices to prevent slipping.
Scaffold platforms must not Scaffold platforms must not be bridged to one another.be bridged to one another.
Werner and Louisville Werner and Louisville produce handrail systems produce handrail systems for ladder jack working for ladder jack working decks.decks.
Trestle Ladder ScaffoldTrestle Ladder Scaffold
Scaffold platforms Scaffold platforms must be placed no must be placed no higher than the higher than the second-highest rung of second-highest rung of the ladderthe ladder
A conventional step A conventional step ladder is not to be ladder is not to be used for this scaffold used for this scaffold configurationconfiguration
Work platforms must Work platforms must be securebe secure
All general scaffold and All general scaffold and ladder standards applyladder standards apply
Carpenters Bracket ScaffoldCarpenters Bracket Scaffold Typically constructed of woodTypically constructed of wood Each piece must be properly Each piece must be properly
fitted and securely joinedfitted and securely joined Brackets must be no more than 8 Brackets must be no more than 8
ft. apartft. apart The platform can be no less than The platform can be no less than
two 2’ x 10’ size plankstwo 2’ x 10’ size planks Attachment must occur in one of Attachment must occur in one of
following ways:following ways: Hook over a well secured and Hook over a well secured and
strong supporting memberstrong supporting member A bolt of no less than 5/8” A bolt of no less than 5/8”
diameter extended through the diameter extended through the inside of the building wallinside of the building wall
Unit attaches via metal stud or Unit attaches via metal stud or welding if possible welding if possible
It can be hung on the It can be hung on the inside or outside of inside or outside of the wallthe wall
Fall protection Fall protection attachments are attachments are availableavailable
The horizontal beam The horizontal beam positional is positional is adjustableadjustable
The Wall WalkerThe Wall Walker General Framing, General Framing,
exterior face hanging exterior face hanging on top plateon top plate
Handrail System in Handrail System in placeplace
Setting pre-fab Setting pre-fab trussestrusses
Aluminum walk deck Aluminum walk deck locked into placelocked into place
The Wall WalkerThe Wall Walker
Cutting tails on raftersCutting tails on rafters Using inside wall Using inside wall
position from top plateposition from top plate
Easy stow and carryEasy stow and carry Unit folds down, Unit folds down,
handrail post stores handrail post stores inside vertical supportinside vertical support
Wall Walker HardwareWall Walker Hardware
Mid Wall BracketMid Wall Bracket
Hand Rail BracketsHand Rail Brackets
Stabilizer BarStabilizer Bar
Manually Propelled Mobile Manually Propelled Mobile ScaffoldsScaffolds
Also known as a “Perry” or Also known as a “Perry” or “Baker” scaffold.“Baker” scaffold.
The casters and wheels must be The casters and wheels must be locked to prevent movement while locked to prevent movement while the scaffold is stationary.the scaffold is stationary.
An employee may ride this An employee may ride this scaffold under the following scaffold under the following conditions:conditions: The floor is level and free of all The floor is level and free of all
obstructionsobstructions The minimum dimension of the The minimum dimension of the
scaffold base is at least half the scaffold base is at least half the heightheight
The wheels are equipped with The wheels are equipped with rubber or some other resilient rubber or some other resilient materialmaterial
All tools and materials are secured All tools and materials are secured or removed prior to movementor removed prior to movement
Because the wheels and castors Because the wheels and castors must be locked once the scaffold must be locked once the scaffold is set, this prohibits movement is set, this prohibits movement from being a one-man operation.from being a one-man operation.
Rustgo Manual Work Rustgo Manual Work PlatformPlatform
All-terrain motorless All-terrain motorless work platform with rear work platform with rear steering capabilitiessteering capabilities
Can be towed to jobsite Can be towed to jobsite location on a standard location on a standard hitchhitch
Winch system on each Winch system on each upright raises and lowers upright raises and lowers work platformwork platform
Front handrail system is Front handrail system is completely removablecompletely removable
Employees cannot stay Employees cannot stay on work platform during on work platform during movementmovement
All general scaffold All general scaffold standards applystandards apply
Horse ScaffoldsHorse Scaffolds
Horses must be spaced not Horses must be spaced not more than 5 ft. for medium more than 5 ft. for medium duty, not more than 8 ft. duty, not more than 8 ft. for light dutyfor light duty
For stacking applications, For stacking applications, must not exceed two tiers must not exceed two tiers or ten feet in heightor ten feet in height
Horses must be inspected Horses must be inspected for defects prior to usefor defects prior to use
All general scaffold All general scaffold standards applystandards apply
MembersMembers DimensionDimensionss
Horizontal Horizontal BearerBearer
3 x 4” 3 x 4”
LegsLegs 111/41/4” x 4” x 41/21/2””
Braces Braces between Legsbetween Legs
1 x 6”1 x 6”
Gusset Brace Gusset Brace at top of Legsat top of Legs
1 x 8”1 x 8”
Half Diagonal Half Diagonal BracesBraces
111/41/4 x 4 x 41/21/2””
Adjustable ScaffoldsAdjustable Scaffolds
Use is more common Use is more common to commercial projectsto commercial projects
Pre-shift inspection of Pre-shift inspection of all components is all components is criticalcritical Hoist MotorsHoist Motors OutriggersOutriggers All Fastening PointsAll Fastening Points
All general scaffold All general scaffold standards applystandards apply
Crawling board must be at Crawling board must be at least 10” wide and 1” least 10” wide and 1” thickthick
CleatsCleats Must be at least 1” x 1Must be at least 1” x 11/21/2”” Must be as long as the board Must be as long as the board
is wideis wide Must be spaced equally at Must be spaced equally at
no more than 2’ apart no more than 2’ apart If the crawling board If the crawling board
presents a fall exposure, presents a fall exposure, fall protection must be fall protection must be used i.e. handrails-used i.e. handrails-harnessharness
Scissor LiftsScissor Lifts
Scissor lifts are not addressed by Scissor lifts are not addressed by the aerial lift provisions of Subpart the aerial lift provisions of Subpart L. L.
There are no OSHA provisions that There are no OSHA provisions that address scissor lifts, however, address scissor lifts, however, employers must comply with the employers must comply with the applicable provisions of Subpart L, applicable provisions of Subpart L, both general and specific.both general and specific.
Example:Example: Scissor lifts are mobile, the specific requirements Scissor lifts are mobile, the specific requirements
for mobile scaffolds standard (§1926.452 (w) - for mobile scaffolds standard (§1926.452 (w) - mobile scaffolds) shall be used.mobile scaffolds) shall be used.
Scissor lifts Scissor lifts do notdo not require a require a personal fall arrest system for personal fall arrest system for occupants.occupants.
Aerial LiftsAerial Lifts Occupants of an aerial Occupants of an aerial
lift must use a personal lift must use a personal fall arrest system.fall arrest system.
Occupants are required Occupants are required to stay on the floor of to stay on the floor of the basket at all times.the basket at all times.
Pre-shift inspection is Pre-shift inspection is critical to insure safe critical to insure safe operation.operation.
The lift may not be field The lift may not be field modified without the modified without the manufacturers consent.manufacturers consent.
Scaffold ChecklistScaffold ChecklistStability of the ground or work Stability of the ground or work surface, proper mud sills when surface, proper mud sills when neededneeded
All components from the same All components from the same manufacturermanufacturer
Adjustable screw jacks with base Adjustable screw jacks with base pads in every postpads in every post
External ladder access for steel External ladder access for steel scaffold bucks not designed for scaffold bucks not designed for climbingclimbing
Erection, dismantle, alteration Erection, dismantle, alteration done under supervision of a done under supervision of a competent personcompetent person
Complete decking from front to Complete decking from front to back on all working levelsback on all working levels
Fall protection in place once work Fall protection in place once work deck reaches or exceeds 10 ft. for deck reaches or exceeds 10 ft. for conventional scaffoldsconventional scaffolds
Daily inspection performed by a Daily inspection performed by a competent person before and during competent person before and during the shiftthe shift
Scaffold must be designed to hold Scaffold must be designed to hold four times the intended working four times the intended working load (safety factor of “4”)load (safety factor of “4”)
Tie-ins set once the height of the Tie-ins set once the height of the scaffold exceeds four times the scaffold exceeds four times the minimum base dimensionminimum base dimension
Scaffold grade planking or better Scaffold grade planking or better for all work surfacesfor all work surfaces
Planks overlapped over horizontal Planks overlapped over horizontal support no less than 12”support no less than 12”
Overhead protection for other Overhead protection for other trades or personnel belowtrades or personnel below
Pre-shift inspection of all Pre-shift inspection of all motorized components, proper PPE motorized components, proper PPE in usein use
