Scaffolds by HBAA

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Scaffolds

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Scaffolds by HBAA

  1. 1. ScaffoldsScaffolds These handouts and documents with attachments are not final, complete, or definitive instruments. This information is for guidance purposesThese 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 liability for damagesonly. 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 any of the terms, conditions,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 explicitly followed by the fund member. Seekand/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.specific guidance from the appropriate regulator (OSHA) or professional advisor.
  2. 2. Introduction to ScaffoldsIntroduction to Scaffolds  OSHA revised theOSHA revised the scaffold standard inscaffold standard in 1997 due to the1997 due to the following;following;  A quarter of the workersA quarter of the workers responsible for installingresponsible for installing work platforms andwork platforms and inspecting, and assemblinginspecting, and assembling them had no formal training.them had no formal training.  Only 1/3 of scaffolds wereOnly 1/3 of scaffolds were equipped with handrails.equipped with handrails.
  3. 3. Defining a Competent PersonDefining a Competent Person  One who is capable of identifying existing andOne who is capable of identifying existing and predictable hazards in the surroundings, orpredictable hazards in the surroundings, or working conditions which are unsanitary,working conditions which are unsanitary, hazardous, or dangerous to employees, andhazardous, or dangerous to employees, and who haswho has authorization to eliminateauthorization to eliminate them.them.  ScaffoldsScaffolds shall beshall be constructed, altered, orconstructed, altered, or dismantleddismantled under the supervision of aunder the supervision of a competent person.competent person.
  4. 4. General RequirementsGeneral Requirements  All scaffolds must be inspected prior to use.All scaffolds must be inspected prior to use.  10’ is the point at which some means of fall10’ is the point at which some means of fall protection must be used.protection must be used.  Top handrails should be around 42”, with theTop handrails should be around 42”, with the mid-rail about half way at 21”.mid-rail about half way at 21”.  Toe boards or other adequate means ofToe boards or other adequate means of falling object protection must be installed iffalling object protection must be installed if there is a possibility of anything falling andthere is a possibility of anything falling and striking someone below.striking someone below.
  5. 5. General RequirementsGeneral Requirements  All scaffolds must supportAll scaffolds must support their own weight and 4xtheir own weight and 4x the maximum intendedthe maximum intended load.load.  Vertical tie-in or outriggerVertical tie-in or outrigger support is not necessary onsupport is not necessary on a free-standing scaffold untila free-standing scaffold until the height exceeds thethe height exceeds the minimum dimension of theminimum dimension of the base by four times.base by four times.
  6. 6. General RequirementsGeneral Requirements  Ladder use on aLadder use on a scaffold is prohibited.scaffold is prohibited.  Platforms must bePlatforms must be kept clear of debris.kept clear of debris.  Do not load sideDo not load side brackets. Most arebrackets. Most are rated at 25 lbs/ft²rated at 25 lbs/ft² maximum.maximum.
  7. 7. 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 supportEach abutted end of a plank shall rest on a separate support surface.surface.  Overlap platforms not less than 12” only over supports, unlessOverlap platforms not less than 12” only over supports, unless restrained to prevent movement, i.e. ”Cleating”.restrained to prevent movement, i.e. ”Cleating”.  The working deck should never be more than 14” away from theThe working deck should never be more than 14” away from the working surface.working surface.
  8. 8. Decks And PlankingDecks And Planking  A scaffold grade plank will beA scaffold grade plank will be stamped or marked as suchstamped or marked as such  Plank must be laminated orPlank must be laminated or solid drawnsolid drawn  A lumber yard 2 x 10 can beA lumber yard 2 x 10 can be used if it is free of knots orused if it is free of knots or other defectsother defects Rough Sawn, Full DimensionRough Sawn, Full Dimension LumberLumber Nominal Thickness LumberNominal Thickness Lumber Working LoadWorking Load in lbs/ft²in lbs/ft² 2525 5050 7575 2525 5050 7575 PermissiblePermissible Span in FeetSpan in Feet 1010 88 66 88 66 66
  9. 9. Overhead Power LinesOverhead Power Lines  The clearance between scaffolds and powerThe clearance between scaffolds and power lines is as follows:lines is as follows: Insulated LinesInsulated Lines Minimum DistanceMinimum Distance < 300 V< 300 V 3’3’ 300 to 50 kV300 to 50 kV 10’10’ > 50 kV> 50 kV 10’ + 1/2”10’ + 1/2” for every additional kVfor every additional kV Uninsulated LinesUninsulated Lines Minimum DistanceMinimum Distance < 50 kV< 50 kV 10’10’ > 50 kV> 50 kV 10’ + 1/2”10’ + 1/2” for every additional kVfor every additional kV
  10. 10. Frame ScaffoldsFrame Scaffolds  Systems should use only originalSystems should use only original parts. Components from differentparts. Components from different systems should not be mixed.systems should not be mixed.  All frame scaffolds must use aAll frame scaffolds must use a manufactured base pad. Verticalmanufactured base pad. Vertical tubes should never sit directly ontubes should never sit directly on the ground or make-shift mud sill.the ground or make-shift mud sill.  X-braces may serve as a top-railX-braces may serve as a top-rail or mid-rail, but not both.or mid-rail, but not both.  If aluminum walking decks areIf aluminum walking decks are used, be sure that end hooks areused, be sure that end hooks are in place and that the dimensionsin place and that the dimensions match the scaffold.match the scaffold.
  11. 11. Frame Scaffolds - AccessFrame Scaffolds - Access Ladder FrameLadder Frame Walk-ThroughWalk-Through OK for Climbing Must have External Access
  12. 12. Frame Scaffolds - AccessFrame Scaffolds - Access  Erectors can climb either type,Erectors can climb either type, but provisions for safe accessbut provisions for safe access should be established as soonshould be established as soon as possible.as possible.  Bottom rung cannot be moreBottom rung cannot be more than two feet high.than two feet high.  Options for access areOptions for access are manufactured bolt-on laddermanufactured bolt-on ladder system, stair system, orsystem, stair system, or extension ladder secured andextension ladder secured and sloped properly.sloped properly.  X-braces are not intended forX-braces are not intended for use as access.use as access.
  13. 13. ““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 aWalk 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 mustWalk boards must hang over bearer a minimum of 6”.Walk boards must overlap each other a minimum of 12”.overlap each other a minimum of 12”.  2” x 4” top rail, mid rail, and toe board2” x 4” top rail, mid rail, and toe board
  14. 14. Stick Built ScaffoldsStick Built Scaffolds  Proper overlapProper overlap on deckon deck plankingplanking  Top rail andTop rail and mid railmid rail establishedestablished after deckafter deck height reachesheight reaches ten feetten feet  AdequateAdequate supportsupport betweenbetween stanchionsstanchions  Proper mudProper mud sills undersills under polespoles  Is this scaffoldIs this scaffold complete?complete?
  15. 15. Pump Jack ScaffoldsPump Jack Scaffolds  Pump Jack brackets, braces,Pump Jack brackets, braces, and accessories must beand accessories must be fabricated from metal.fabricated from metal.  Each pump jack bracket mustEach pump jack bracket must have two positive grippinghave two positive gripping mechanisms.mechanisms.  Poles should be secured toPoles should be secured to the structure with triangularthe structure with triangular bracing.bracing.  Work benches should not beWork benches should not be used as a working deck.used as a working deck.  If 2x4’s are spliced to make aIf 2x4’s are spliced to make a pole, mending plates must bepole, mending plates must be installed to maintain strength.installed to maintain strength.
  16. 16. Ladder Jack ScaffoldsLadder Jack Scaffolds  Platforms must not exceed 20’Platforms must not exceed 20’ in height.in height.  Job made ladders cannot beJob made ladders cannot be used to support ladder jackused to support ladder jack scaffolds.scaffolds.  Ladders that support ladderLadders that support ladder jacks must be placed, fastened,jacks must be placed, fastened, or equipped with devices toor equipped with devices to prevent slipping.prevent slipping.  Scaffold platforms must not beScaffold platforms must not be bridged to one another.bridged to one another.  Werner and Louisville produceWerner and Louisville produce handrail systems for ladder jackhandrail systems for ladder jack working decks.working decks.
  17. 17. Trestle Ladder ScaffoldTrestle Ladder Scaffold  Scaffold platforms mustScaffold platforms must be placed no higher thanbe placed no higher than the second-highest rungthe second-highest rung of the ladderof the ladder  A conventional stepA conventional step ladder is not to be usedladder is not to be used for this scaffoldfor this scaffold configurationconfiguration  Work platforms must beWork platforms must be securesecure  All general scaffold andAll general scaffold and ladder standards applyladder standards apply
  18. 18. Carpenters Bracket ScaffoldCarpenters Bracket Scaffold  Typically constructed of woodTypically constructed of wood  Each piece must be properly fitted andEach piece must be properly fitted and securely joinedsecurely joined  Brackets must be no more than 8 ft.Brackets must be no more than 8 ft. apartapart  The platform can be no less than twoThe platform can be no less than two 2’ x 10’ size planks2’ x 10’ size planks  Attachment must occur in one ofAttachment must occur in one of following ways:following ways:  Hook over a well secured and strongHook over a well secured and strong supporting membersupporting member  A bolt of no less than 5/8” diameterA bolt of no less than 5/8” diameter extended through the inside of theextended through the inside of the building wallbuilding wall  Unit attaches via metal stud or weldingUnit attaches via metal stud or welding if possibleif possible
  19. 19. Hanging Scaffold SystemHanging Scaffold System The Wall WalkerThe Wall Walker  Device meets OSHADevice meets OSHA standardsstandards  It can be hung on theIt can be hung on the inside or outside of theinside or outside of the wallwall  Fall protectionFall protection attachments areattachments are availableavailable  The horizontal beamThe horizontal beam positional is adjustablepositional is adjustable
  20. 20. The Wall WalkerThe Wall Walker  General Framing,General Framing, exterior face hangingexterior face hanging on top plateon top plate  Handrail System inHandrail System in placeplace  Setting pre-fab trussesSetting pre-fab trusses  Aluminum walk deckAluminum walk deck locked into placelocked into place
  21. 21. The Wall WalkerThe Wall Walker  Cutting tails on raftersCutting tails on rafters  Using inside wallUsing inside wall position from top plateposition from top plate  Easy stow and carryEasy stow and carry  Unit folds down,Unit folds down, handrail post storeshandrail post stores inside vertical supportinside vertical support
  22. 22. Wall Walker HardwareWall Walker Hardware  Mid Wall BracketMid Wall Bracket  Hand Rail BracketsHand Rail Brackets  Stabilizer BarStabilizer Bar
  23. 23. Manually Propelled MobileManually Propelled Mobile ScaffoldsScaffolds  Also known as a “Perry” or “Baker”Also known as a “Perry” or “Baker” scaffold.scaffold.  The casters and wheels must beThe casters and wheels must be locked to prevent movement while thelocked to prevent movement while the scaffold is stationary.scaffold is stationary.  An employee may ride this scaffoldAn employee may ride this scaffold under the following conditions:under the following conditions:  The floor is level and free of allThe floor is level and free of all obstructionsobstructions  The minimum dimension of theThe minimum dimension of the scaffold base is at least half the heightscaffold base is at least half the height  The wheels are equipped with rubberThe wheels are equipped with rubber or some other resilient materialor some other resilient material  All tools and materials are secured orAll tools and materials are secured or removed prior to movementremoved prior to movement  Because the wheels and castorsBecause the wheels and castors must be locked once the scaffold ismust be locked once the scaffold is set, this prohibits movement fromset, this prohibits movement from
  24. 24. Rustgo Manual Work PlatformRustgo Manual Work Platform  All-terrain motorless workAll-terrain motorless work platform with rear steeringplatform with rear steering capabilitiescapabilities  Can be towed to jobsiteCan be towed to jobsite location on a standard hitchlocation on a standard hitch  Winch system on eachWinch system on each upright raises and lowersupright raises and lowers work platformwork platform  Front handrail system isFront handrail system is completely removablecompletely removable  Employees cannot stay onEmployees cannot stay on work platform duringwork platform during movementmovement  All general scaffoldAll general scaffold standards applystandards apply
  25. 25. Horse ScaffoldsHorse Scaffolds  Horses must be spaced notHorses must be spaced not more than 5 ft. for mediummore than 5 ft. for medium duty, not more than 8 ft. forduty, not more than 8 ft. for light dutylight duty  For stacking applications, mustFor stacking applications, must not exceed two tiers or ten feetnot exceed two tiers or ten feet in heightin height  Horses must be inspected forHorses must be inspected for defects prior to usedefects prior to use  All general scaffold standardsAll general scaffold standards applyapply MembersMembers DimensionsDimensions HorizontalHorizontal BearerBearer 3 x 4”3 x 4” LegsLegs 111/41/4” x 4” x 41/21/2”” BracesBraces between Legsbetween Legs 1 x 6”1 x 6” Gusset BraceGusset Brace at top of Legsat top of Legs 1 x 8”1 x 8” Half DiagonalHalf Diagonal BracesBraces 111/41/4 x 4x 41/21/2””
  26. 26. Adjustable ScaffoldsAdjustable Scaffolds  Use is more common toUse is more common to commercial projectscommercial projects  Pre-shift inspection of allPre-shift inspection of all components is criticalcomponents is critical  Hoist MotorsHoist Motors  OutriggersOutriggers  All Fastening PointsAll Fastening Points  All general scaffoldAll general scaffold standards applystandards apply
  27. 27. Crawling Boards / Chicken LaddersCrawling Boards / Chicken Ladders  Crawling board must be atCrawling board must be at least 10” wide and 1” thickleast 10” wide and 1” thick  CleatsCleats  Must be at least 1” x 1Must be at least 1” x 11/21/2””  Must be as long as the board isMust be as long as the board is widewide  Must be spaced equally at noMust be spaced equally at no more than 2’ apartmore than 2’ apart  If the crawling boardIf the crawling board presents a fall exposure, fallpresents a fall exposure, fall protection must be used i.e.protection must be used i.e. handrails-harnesshandrails-harness
  28. 28. Scissor LiftsScissor Lifts  Scissor lifts are not addressed by theScissor lifts are not addressed by the aerial lift provisions of Subpart L.aerial lift provisions of Subpart L.  There are no OSHA provisions thatThere are no OSHA provisions that address scissor lifts, however,address scissor lifts, however, employers must comply with theemployers 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 forScissor lifts are mobile, the specific requirements for mobile scaffolds standard (§1926.452 (w) - mobilemobile scaffolds standard (§1926.452 (w) - mobile scaffolds) shall be used.scaffolds) shall be used.  Scissor liftsScissor lifts do notdo not require a personalrequire a personal fall arrest system for occupants.fall arrest system for occupants.
  29. 29. Aerial LiftsAerial Lifts  Occupants of an aerial liftOccupants of an aerial lift must use a personal fallmust use a personal fall arrest system.arrest system.  Occupants are required toOccupants are required to stay on the floor of thestay on the floor of the basket at all times.basket at all times.  Pre-shift inspection isPre-shift inspection is critical to insure safecritical to insure safe operation.operation.  The lift may not be fieldThe lift may not be field modified without themodified without the manufacturers consent.manufacturers consent.
  30. 30. Scaffold ChecklistScaffold Checklist Stability of the ground or work surface,Stability of the ground or work surface, proper mud sills when neededproper mud sills when needed All components from the sameAll components from the same manufacturermanufacturer Adjustable screw jacks with base padsAdjustable screw jacks with base pads in every postin every post External ladder access for steelExternal ladder access for steel scaffold bucks not designed for climbingscaffold bucks not designed for climbing Erection, dismantle, alteration doneErection, dismantle, alteration done under supervision of a competent personunder supervision of a competent person Complete decking from front to back onComplete decking from front to back on all working levelsall working levels Fall protection in place once work deckFall protection in place once work deck reaches or exceeds 10 ft. forreaches or exceeds 10 ft. for conventional scaffoldsconventional scaffolds Daily inspection performed by aDaily inspection performed by a competent person before and during thecompetent person before and during the shiftshift Scaffold must be designed to hold fourScaffold must be designed to hold four times the intended working load (safetytimes the intended working load (safety factor of “4”)factor of “4”) Tie-ins set once the height of theTie-ins set once the height of the scaffold exceeds four times the minimumscaffold exceeds four times the minimum base dimensionbase dimension Scaffold grade planking or better for allScaffold grade planking or better for all work surfaceswork surfaces Planks overlapped over horizontalPlanks overlapped over horizontal support no less than 12”support no less than 12” Overhead protection for other trades orOverhead protection for other trades or personnel belowpersonnel below Pre-shift inspection of all motorizedPre-shift inspection of all motorized components, proper PPE in usecomponents, proper PPE in use

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