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Scaffolding Training

basic scaffolding

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Purpose: To establish the minimum safetyrelated technical requirements for temporary elevated work areas, ladders, and scaffolds. Purpose: To establish the minimum safetyrelated technical requirements for temporary elevated work areas, ladders, and scaffolds. TOP RAIL MID RAIL DROP BAR 0.95m  !.!5 m FALSE UPRIGHT ("#$%&5$) "'$ m. SCAFFOLD PLANKS BEARER (TRANSOM) LONGITUDINAL BRACING LADDER CLAMP TOEBOARD STANDARD SWIVEL COUPLER FIXED COUPLER (90º) RUNNER (LEDGER) TRANSVERSE BRACING BASE LIFT  (KICKER LIFT) BASE PLAT P LATE E SILL (SOLE BOARD) BIOARD BEARER (INTERMEDIATE TRANSOM) BA+ LENGTH RUNNERS (LEDGERS) BEARERS (TRANSOMS) RUNNERS * BEARERS INSTALLED INSIDE POSTS T+P. POST (STANDARD) BASE PLA PL ATES SILLS (SOLE BOARDS) BASE LIFT (KICKER LIFT) BEARERS (TRANSOMS) RUNNERS (LEDGERS) BA+ LENGTH BA+ SCAFFOLD WIDTH LIFT HEIGHT '$ POST (STANDARD) BASE LIFT (F,,- T ,/ K1/ L2-) II. ELEVATED WORK AREAS - GENERAL REQUIREMENTS  FA P!"T#$T%"&   Each person who could fall more than '.( m. )* ft.+  shall be protected from falling by means of guardrail systems or personal fall arrest systems. A!!A% /0/T#1/  Guardrail system shall be able to withstand a force of at least 23k4. )533 lbs.+ It consists '. Toprails  ! top edge height of toprails shall not be less than 3.26 m. )7( 8+ and not more than  '.'6 m. )96+ abo"e the wal#ing$wor#ing surface of a platform. 5. 1idrails % installed appro&imately halfway between the wal#ing$wor#ing surface and toprail. 7. Toeboards % shall ha"e no more than * mm. )';9+  gap abo"e the wor#ing surface and should withstand a force of at least 57 k4 )63 lbs+. 9. pri4hts  % shall not be spaced more than 5.< m. )2 ft.+ apart. 42 4,8 :/,7 ;3/  234 67/8(76,) -,7/34 m:/34 -,;,3/: II. ELEVATED WORK AREAS - GENERAL REQUIREMENTS  P#!/"&A FA A!!#/T /0/T#1/     (ull body harnesses) lanyards) lifelines or o"erhead structural anchorage) and other components of personal fall arrest system shall ha"e a capacity of at least 5,733 k4s. )6,333 lbs.+. *anyards shall ha"e a ma&imum length of '.( m. )* ft.+ thus it shall be anchored high enough to pre"ent the wor#er from free falling more than 6 feet +1.,m.- or stri#ing any lower le"el should a fall occur. ori/ontal and "ertical lifelines shall be made from '3 mm. )7;(+ min. diameter wire rope. ori/ontal lifelines shall be maintained with a sag at the center of no greater than 733mm.. )'5+ for every '3 m. )77 ft.+ of lifeline length between attachments. FA%& "=>#$T P!"T#$T%"&   0oeboards shall be installed on all edges of ele"ated wor# areas more than '.( m. )* ft.+  abo"e lower le"els. It shall conform the ffg. reuirements 1. inimum dimension of '33 mm. )9+  in height and 56 mm. )'+ thic#. 2. o more than * mm. )';9+ abo"e the wor#ing surface. 3. hould withstand a force of at least 57 k4. )63 lbs.+ hen there is a danger for obects falling through guardrails a protecti"e screen )minimum &o. '( 4au4e wire with a ma?imum '7 mm. mesh+ shall be securely fi&ed to the toeboard) midrail and guardrail. II. ELEVATED WORK AREAS - GENERAL REQUIREMENTS  #&T!0 A& #@%T     7 safe means of access shall be pro"ided whene"er the scaffold platform is 3.* m )5 feet+ abo"e or below a point of access. If hori/ontal tra"el distance e&ceeds '6 m )63 feet+ each ele"ated wor# area shall ha"e at least 2 means of e&it. 7 means of e&it shall be pro"ided at least e"ery 73 m )'33 feet+. inimum clear headroom abo"e scaffold platforms shall be '.( meters )* feet+. TEMPORAR+ STAIRWA+S PARTS OF STAIRWA+ LANDING RE: * ?'0 mm. ("0$) 4,8. S344 3@ 43:8 ,- m,/ -3 @/ ".? m. (!=) ,2 @/-34 :-3. • !50 mm. ('$) -, =!5 mm. (#$) :7-. S344 ; 62,/m >- 3 248- ,2 ,2 -3/. TREAD • ==0 mm. (9$) -, =#0 mm. (!!$) >:. STAIR SLOPE • B-> "0 -, "5 :8/ HANDRAIL • #'0 mm. ("&$) -, 9&0 mm. ("?$)  8-. #0 mm. ("$) 43/3 ;-> >344 ,/ ,-/ ,;-. C3 >--3: 3 2,/ ,2 3- 43- 90 18. (=00 4;.) • • • II. ELEVATED WORK AREAS - GENERAL REQUIREMENTS  TEMPORAR+ RAMPS    HIGH WINDS   Personnel shall not be on any scaffold or other temporary elevated work area during storms or high winds – sustained winds more than '5 17 (&0 m7). WORK OVER WATER   Shall not be inclined more than a ratio of !  " ,/ =0º  above the horizontal although a slope not over !5º is preferred. If steeper than ratio !  & the ramp shall have cleats no more than "50 mm (!&$) apart. Personnel working over water shall have floatation ring provided at intervals not greater than !5 m-/ (50 2-) and a man watch shall also be provided. LADDERS      A slope of &! side rails rigidly attached to supporting structure !top middle bottom". #ungs uniformly spaced between =50 mm (!0$) 3: "'0 mm (!&$)  although "00 mm (!= ) is preferred. Shall have a minimum clear distance of ?'0 mm ("0$) to the nearest protruding ob$ect on the climbing side. %his distance maybe reduced to '!0 mm (=& ) if deflector plates are provided. &istance on the climbing side to the nearest ob$ect on the back side of the ladder shall be no less than =50 mm (!0 ). 'hen unavoidable a minimum vertical toe clearance of !00 mm. (&$) shall apply.   ()*)#A+ III. SCAFFOLDING COMPONENTS  Scaffold components manufactured by different manufacturers should not be intermi,ed unless the components are compatible and the scaffold-s structural integrity is maintained.   All defective scaffold component s shall be marked with bright fluorescent orange paint and immediately removed from Saudi Aramco property or pro$ect site. SCAFFOLD TUBING AND FITTINGS SPECIFICATIONS ) /caffold tubin4, 9(.73 mm '.23 inchB nominal outside diameter + Grade Min. Yield Stress (Sy) Nominal Wall Thickness B !0 N"mm# $ ksi %0 &'"mm# %.$0 mm %. mm ASTM A5% B $0 N"mm# %5 ksi $ &'"mm# %.* mm BS ++%! ,art +Sec. +.+ %5 N"mm# %$ ksi $ &'"mm# $.00 mm / %0 N"mm# $ ksi % &'"mm# %.0 mm Type ASTM A500 N +0+! III. SCAFFOLDING COMPONENTS  SCAFFOLD TUBING AND FITTINGS SPECIFICATIONS /afe Corkin4 oad of %ndividual $oupler Type of coupler Type of load 1in. #& <9 class /C )1in.+ !i4ht an4le coupler, )ouble or load bearin4+ /lip alon4 tube A *.56 D& ',933 lbs. AdEustable coupler, )/wivel+ /lip alon4 tube A 6.7 D& ','23 lbs. Tension = 7.3 D& *.<6 lbs. =endin4 = 3.62 D&-m 976 lbs-ft. Force to pull the tube a?ially out of the coupler - 3.67 D& '53 lbs. - 73 D& *,<93 lbs. )per pair+ #nd-end coupler )/leeve+ =earer coupler )Putlo4 ; /in4le+ irder coupler )rop for4ed+ /hear III. SCAFFOLDING COMPONENTS  PLATFORM UNITS W,,: P431 Dm, S,4: S3> =!0  (,m) W,,: =9  (/,68) C/-2:  A77/,@: ; • • "#=5mm ,/ 50==5 mm (;3) L3m3-: V/ L6m;/  "#mm (!%!=$) ; ==5mm (9$) >: ,/ 43/8/  • • W- C,3- L6m;/ I7-, B6/36 (WCLB)  S,6-/ P I7-, B6/36 (SPIB) Am/3 L6m;/ S-3:3/: C,mm-- R6/m- • S344 ; /-2: 3: ;3/ 3 8/3: -3m7 • F/ 2/,m :2- •S74- =5mm (!$) m3. >, ;3:8 "00mm (!)m3. > ;3:8 •T>- !"mm (!=$) m3. : -, : • S344 ,- ; 73-: -/3-: ,/ ,3-: (7- 3- - :) • S344 ; 7/,7/4 -31:. I2 8- -31 : =0 S344 3@ - >,/: 7431 6:8 43/ PROOF TESTED ,64: ; -: ,/ ;,:. SCAFFOLD PLANK$ 3: OSHA$ ,/ • S344 ,- -,,: , : S36: A/3m, 63--:: 37-: 6@34- ,-6,64 m;,: , ;,- :8.  S322,4: 7431 344 ,- ; 6: 3 ,/- 2,/m -/ IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  $APA$%T0     E"ery scaffold and scaffold component shall be capable of supporting) without failure) its own weight +dead load- and at least four +4- times the ma&imum intended load applied or transmitted to it )  9G+. caffolds and scaffold components shall not be loaded in e&cess of their load rating. 0he ma&imum allowable span for plan#s$platforms shall be the shortest span reuired to support) without failure) the platform units own weight and at least four times the most critical ma&imum intended load as shown. 0he ma&imum deflection for platform units shall not e&ceed 1$69 th of the span length when supporting any of the unfactored concentrated or uniformly distributed concentrated loads. IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  F"&AT%"&/   (oundations shall be sound) rigid) and capable of carrying the scaffold self!weight plus the ma&imum intended load without settling or displacement. caffolds shall not be hung from or supported by guardrails or handrails. omponents Tim4er Sills (sole 4oards) Steel Base ,lates Scre 6acks 1e23irements : At least 556 mm. )2+ wide by 7( mm. )'-';5+ thick : /hall e?tend under at least two posts )standard+, if not applicable sills under individual posts shall be at least <*6 mm. )73+ lon4 : At least '63 ? '63mm. H *mm. thick )* ? * inches H ';9 inch thick+ : For special scaffolds base shall be desi4ned : /hall not be adEusted to more than twothirds )5;7+ of the total len4th of the threaded section IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  /TA=%%T0    caffold posts and frames shall be "ertically plumb and "ertically braced in both directions. upported scaffolds with a height to the uppermost plan#ed le"el that is o"er four times the minimum base dimension )over a 9:'hei4ht-towidth ratio+  shall be restrained from tipping by ties) guys) outrigger frames) or eui"alent means. 0ies and guys shall be installed as follows IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  /TA=%%T0  0ies and guys shall be installed as follows  0ies or guys shall be spaced "ertically e"ery ( m. )5*I+)9 lifts+ or less.  0ies or guys shall be installed on both ends of the scaffold and at hori/ontal inter"als not to e?ceed 2 m. )73I+  measured from one end toward the other. IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  STABILIT+ CROSS TUBE IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  /$AFF" PATF"!1 $"&/T!$T%"& A& /#  If the front edge of a wor#ing platform is less than 7*3 mm. )'9+ from the face of the wall or structure) guardrails do not need to be erected from that edge.  (or medium!duty and more hea"ily loaded scaffolds) at least one board bearer +intermediate transom- shall be used in e"ery bay at each platform le"el.  ;lan#s should be secured on both ends by using fiber rope$wire lashing) clamped toe boards or other eui"alent means. ;lan#s < toeboards should not be nailed.  0he slope of platform units shall not e&ceed 1 "ertical to 4 hori/ontal.  caffold platforms) landings) and wal#ways should be at least *<6 mm. )5<+ )7planks+  wide) including during erection) dismantling and alteration.  caffold materials shall not be thrown or dropped from heights. IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  /$AFF" PATF"!1 $"&/T!$T%"& A& /#  Gaps between platform units shall be less than 56 mm. )'+  wide. hen larger gaps are una"oidable) they shall be co"ered as follows o Gaps less than *33 mm. )5I+ in width shall be co"ered at least 53 mm. )'+ thick, e&terior grade plywood. ;lywood co"ering shall be o"erlapped with at least the width of the gap) '5 min.) on both sides of the opening and held with cleats. o Gaps larger than *33 mm. )5I+  in width shall be co"ered with properly secured cross plan#s.  afe landings shall be pro"ided at the top of all ladders and at least e"ery 2m. )73I+ of ladder height.  If an internal ladder is used) opening shall be at least *<6mm. )5<+ )7 planks+ wide < not less than 233mm )7*+ deep.  If an e&ternal ladder is used) step!through opening width on guardrails shall not be less than *<6 mm. )5<+ or more than <*3 mm. )73+.  0he slope of scaffold platform units shall not e&ceed  ' vertical to 9 horiJontal. IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  SCAFFOLD PLATFORM CONSTRUCTION AND USE IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  $#A!A&$#/  caffold operations adacent to o"erhead power lines are prohibited unless one of the following conditions are satisfied o 0he power line has been de!energi/ed) relocated) or protecti"e co"erings installed to pre"ent accidental contact with the lines. It should be loc#out$tagut. o atisfies clearance between scaffold and power lines. $#A!A&$#/ =#TC##& /$AFF"/ A& P"C#! %&#/: Insulated Minimum Distance Uninsulated Less than 300 Volts. 1 meter (3 feet) - - - - - 300 Volts to 50 K. 3 meters (10 feet) Less than 50 K. More than 50 K. 3 meters (10 feet) ! " inches #er K oer 50 K. More than 50 K. A4-/3-@ = - 48- ,2 - 4 643-,/ ;6- @/ 4 -3 " m-/ (!0 2-).  =ases of scaffold shall be at least '.6 times the depth of e?cavation away from the edges of the e&ca"ations +including trenches-. IV. REQUIREMENTS COMMON TO ALL SCAFFOLDS  !A%/%& A& "C#!%& 1AT#!%A/ /%& %& CK##/   0he gin wheel shall be mounted on a cantile"ered hori/ontal tube proecting outward from the scaffold and shall be #ept to a minimum distance) not greater than <63 mm. )73+.  0ube shall be fi&ed with right!angle couplers to two scaffold post +standard-. aterials to be raised shall not e&ceed 63 k4. )''3 lbs.+, the rope shall be of the correct si/e to suit the gin wheel) usually '(-mm. )7;9+. L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  T0P%$A T=# H $"P#! /$AFF" GUARDRAIL S+STEM INCLUDING TOEBOARDS PLANKING (BOARDS) TOEBOARD CLIPS RUNNER (LEDGER) BEARER (TRANSOM) RIGHT%ANGLE (DOUBLE) COUPLER POST (STANDARD) !&$ THK. (M.) BASE PLATE ADUSTABLE (SWIVEL) COUPLER TRANSVERSE CROSS (X$) BRACING SILL LONGITUDINAL (FAJADE) BRACING !50 mm. !50 mm. ('$) M. ('$) M. L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  K"!%N"&TA 1#1=#!/  &o lift hei4ht shall e?ceed 5m. L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  HORIONTAL MEMBERS  =earers +transoms- and board bearers +intermediate transom- shall be installed on top of and not underneath supporting runners.  E"ery line of posts +standards- shall ha"e runners +ledgers- installed hori/ontally in continuous lengths along the entire scaffold length +longitudinally- and bearers +transoms- installed in continuous lengths across the entire scaffold width +trans"ersely-) at each lift. L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  K"!%N"&TA 1#1=#!/  =ridging of scaffolds shall be as conceptually as follows L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  K"!%N"&TA 1#1=#!/  =ridging of scaffolds L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  K"!%N"&TA 1#1=#!/  =ridging of scaffolds L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  =racin4    >ertical bracing to pre"ent e&cessi"e sway is necessary in both the trans"erse and longitudinal direction of all system and tube < coupler scaffolds for the full height of the scaffold. 0rans"erse +sectional- braces shall be connected to either posts +standards- or runners +ledgers- as close as possible to the intersection +node point- of the bearer +transom- and post +standard-. *ongitudinal +fa?ade- braces shall be connected to posts +standards- as close as possible to the intersection +node point- of the runner +ledgerand post +standard-. L. !#M%!#1#&T/ $"11"& T" /0/T#1 A& T=# H $"P#! /$AFF"/  B/38  =race ends may be oined together with end!to!end +slee"e- couplers. 7lternati"ely) for braces subect to large tension loads) shall be o"erlapped < oined with at least two adustable +swi"el- couplers)  VI. SYSTEM SCAFFOLDS /ystem /caffolds  7ll system scaffolds shall be erected per manufacturer@s published instructions  /ystem /caffolds  Anless otherwise specified in manufacture@s instruction) all system scaffold shall be "ertically braced in both directions with diagonal braces )as close to 96O as possible+ to its full hei4ht for each '3 m. )77I+ of run.  Bomponents from different scaffold manufacturers intermi&ed +e&cept when needed in bracing-.  here specially designed system bracing cannot be used) tube < coupler scaffold components may be used for bracing of system scaffolds.  Bonnections shall be tightened with a single hammer blow to the wedge or cup to pro"ide high degree of rigidity.  hall be connected by means of one of the following fastening methods o Bapti"e wedge system +such as audi caffolding (actory +CDwi#stageo Fuic#!fi& system +such as *ayher C7ll!aroundo Bup loc#ing system +such as G= CBuploc#-  ystem scaffold components shall not be used to construct underhung scaffolds. shall not be  /ystem /caffolds  0he loc#ing!pin type of system scaffold shall not be used.  ;osts +standards- shall be connected by bolted spigots and shall be secured into place using two spigot pins for situations where uplift may occur. 0he upper post +standard- shall slide o"er the spigot.  /ystem /caffolds  Anless otherwise ustified and stated in writing by the system scaffold manufacturer) the ma&imum number of wor#ing le"els and total plan#ed le"els shall be as follows LIGHT DUTY 1a?imum &umber of Corkin4 evels 1a?. Total &umber Planked;Platformed evels 1a?imum /caffold Kei4ht ' 2 7( m. )'56 ft.+ 5 * 7( m. )'56 ft.+ 7 7 5( m. )2' ft.+ MEDIUM DUTY 1a?imum &umber of Corkin4 evels 1a?. Total &umber Planked;Platformed evels 1a?imum /caffold Kei4ht ' < 7( m. )'56 ft.+ 5 5 59 m. )<( ft.+ VII. TUBE AND COUPLER SCAFFOLDS T0P%$A T=# H $"P#! /$AFF" GUARDRAIL S+STEM INCLUDING TOEBOARDS PLANKING (BOARDS) TOEBOARD CLIPS RUNNER (LEDGER) BEARER (TRANSOM) RIGHT%ANGLE (DOUBLE) COUPLER POST (STANDARD) !&$ THK. (M.) BASE PLATE ADUSTABLE (SWIVEL) COUPLER TRANSVERSE CROSS (X$) BRACING SILL LONGITUDINAL (FAJADE) BRACING !50 mm. !50 mm. ('$) M. ('$) M.  P"/T/  oint pins or) preferably) end!to!end +slee"e- couplers shall be used for  oints in post +standards-. owe"er) oint pins are only designed for compression load. End!to!end couplers shall be used where tension +uplift- can be present in a posts +standard- or other scaffold tube.  oints in posts +standards- shall be staggered. oints in adacent posts shall not occur in the same lift height.  !&&#!/ )##!/+ A& =#A!#!/ )T!A&/"1/+    Hunners +ledgers- and bearers +transoms- shall be securely fi&ed to the inside of each posts. +standard-. hen bearers +transoms- and board bearers +intermediate transomsare coupled to runners +ledgers- they shall always be installed on top of the supporting runners =earers +transoms-) including board bearers) shall e&tend at least '33 mm. )9+ beyond the runner centerline.  !&&#!/ )##!/+ A& =#A!#!/ )T!A&/"1/+  Hunners +ledgers- shall be connected to posts +standards- only with right!angle +load bearing- couplers.  hen bearers +transoms- are coupled to posts +standards-) the bearer shall be connected to the posts only with right!angle +load bearingcouplers and the coupler shall rest directly on the runners +ledgersright!angle couplers.  hen a bearer +transom- is coupled to a supporting runner +ledger-) the coupler shall ne"er be more than 733 mm. )'5+ apart from the post.  7t lifts to be plan#ed) right!angle couplers should not be used to attach bearers or board bearers to runners) because the coupler bolts may interfere with proper placement of plan#s. Instead bearer +putlogcouplers shall be used.  !&&#!/ )##!/+ A& =#A!#!/ )T!A&/"1/+  Hunners +ledger- or bearers +transoms- shall not ha"e more than one  oint between adacent posts) oints shall be staggered +adacent oints shall not occur on the same bay-.  End!to!end couplers may be used may be used for oints in runners +ledgers- or bearers +transoms-) the oint shall not be located more than 733mm. )'5+ from a post +standard-.   Alternatively $oints in runners or bearers may be made by abutting the runner or bearer ends together and overlapping this ends with a separate parallel tube. %his parallel tube shall be coupled to each abutted runner or bearer end with at least two eually spaced ad$ustable swivel couplers. In this case - ,- 344 ,; 4,3-:  - m::4 -/: ,2 - /6/ ,/ ;3// 73.  RUNNERS (LEDGERS) AND BEARERS (TRANSOMS)  Hight!angle +double- couplers shall be installed such that the load is against the hinge and not against the bolt.  caffold couplers shall be tightened to the torue as indicated by the manufacturer preferably between 93 k4-m. )73 ft.-lbs.+ and (3 k4-m. )*3 ft-lbs.+  nly proper scaffold spanner wrenches shall be used. 8$heater bars or lon4er handled wrenches shall not be used) as they gi"e greater le"erage than proper scaffold spanner wrenches and could damage the coupler.  L#!T%$A =!A$%& ) Transverse 8Ni4Ja4 =racin4+  0rans"erse +sectional- C/ig/ag bracing 0he first diagonal brace shall be installed from the base of the first post +standard- diagonally upward to the first lift at whiche"er post +standard- is reuired to ma#e the angle of the diagonal brace be between 76 and 66 de4rees +may be across two bays in one lift height-. 7dditional diagonal braces shall be installed in alternating directions +C/ig/ag- until reaching the top of the scaffold.  L#!T%$A =!A$%& ) Transverse 8Ni4Ja4 =racin4+  (or wide scaffolds) this trans"erse C/ig/ag bracing shall be shall be repeated across the width of the scaffold such that no more than 7 adEacent bays are open without trans"erse bracing. 0his set of trans"erse C/ig!/ag braces shall be installed at both scaffold ends and repeated along the length of the scaffold at least every third line of posts )standards+.  L#!T%$A =!A$%& ) Transverse 8Ni4Ja4 =racin4+  (or wide scaffolds  L#!T%$A =!A$%& )Transverse 8@ =racin4+  Transverse )sectional+ 8@ bracin4:  the first two diagonal braces are installed forming an  CJ shape. 0hus) the first brace is installed from the base of the first post +standard- diagonally upward to the first lift at the post +standard- reuired for the base to be between 76 and 66 de4rees  +may be across two bays in one lift height-. 0he second brace is installed from the base of the same post +standarddiagonally upward to the first post +standard-. 0his CJ bracing should be repeated up to the height of the scaffold at least e"ery third lift +two adacent open lift heights permitted.  L#!T%$A =!A$%& )Transverse 8@ =racin4+  (or wide scaffolds) such trans"erse CJ bracing shall be repeated across the width of the scaffold such that no more than 7 adEacent bays are open without trans"erse bracing. 0his set of trans"erse CJ braces shall be installed at both scaffold ends and repeated along the length of the scaffold at least e"ery third line of posts +standards-.  VERTICAL BRACING )on4itudinal 8Facade =racin4+  L,8-6:34 (233:) ;/38 2,/ 3 322,4: >, 48-  8/3-/ -3 - 8-/ A diagonal brace shall be installed from the base of the first post !standard" upward at between "5 3: 55 :8/ to the e,treme top of the scaffold. %his longitudinal bracing shall be repeated along the length of the scaffold 3- 43- @/ 5- 7,- (-3:3/:). %his longitudinal !fa0ade" bracing shall be installed in opposite directions along the front !inner" and rear !outer" lines of posts !standards".  L#!T%$A =!A$%& )on4itudinal 8Facade =racin4+  on4itudinal )faade+ bracin4 for a scaffold whose len4th is less than its hei4ht:  0he first diagonal brace shall be installed from the base of the first end post +standard- upward) at between 76 and 66 de4rees) along the entire length of the scaffold to the last end post. 7dditional diagonal braces shall then be installed) at between 35 and 55 degrees) in alternating directions +C/ig/agacross the entire scaffold length until reaching the top of the scaffold. 0his longitudinal +fa?adebracing shall be installed in opposite directions) along the front +inner- and rear +outer- lines of posts +standards-.  VERTICAL BRACING )%nterior on4itudinal 8Ni4-Ja4 =racin4+  I-/,/ 4,8-6:34 8%38$ ;/38 2,/ 3 322,4: >- m64-74 ;3 3/, - >- (;/:38$ 322,4:) %he first diagonal brace shall be installed from the base of the first post !standard" diagonally upward at between "5 3: 55 :8/ to the second post at the first lift (3/, , ;3  , 428-).  Additional diagonal braces shall then be installed in alternating directions !1zig2 zag3" until reaching the top of the scaffold. Such longitudinal 1zig2zag3 bracing shall be repeated along the length of the scaffold such that no more than 4 ad$acent bays are open without longitudinal braces. %his set of longitudinal 1zig2zag3 braces shall be repeated across the width of the scaffold at least every third line of post.  %KT-T0 T=# A& $"P#! /$AFF"/  LIGHT-DUTY SCAFFOLD LOADING   LIGHT%DUT+ TUBE AND COUPLER SCAFFOLDS    Embossed  L8-%:6- m4oss ed T34in' T6; * C,674/ S322,4: P,- S738 N3m4er o7 5mm (!8) ide planks per 4ay idth Trans9erse post Spacin' (Bearer"Transom Span) :on'it3dinal ,ost Spacin' (13nner":ed'er Span) ;ption + "PT%"& ' $ +.0 m (%.5 7t.) . m (!.0 7t.) ma<. ;ption  5 +. m ($.0 7t.) .$ m (*.0 7t.) ma<.  LIGHT%DUT+ TUBE AND COUPLER SCAFFOLDS    Embossed  L8-%:6- "PT%"& 5 T6; * C,674/ S322,4: P,- S738  LIGHT%DUT+ TUBE AND COUPLER SCAFFOLDS    Non-Embossed  L8-%:6- T6; * C,674/ S322,4: P,- S738 !5ased on 46.7 mm 8.&. 7.9 mm wall thickness :y ; 97< *=mm9 !74 ksi" steel tubing" m4oss ed T34in' N3m4er o7 5mm (!8) ide planks per 4ay idth Trans9erse post Spacin' (Bearer"Transom Span) :on'it3dinal ,ost Spacin' (13nner":ed'er Span) ;ption + "PT%"& ' $ +.0 m (%.5 7t.) .% m (.5 7t.) ma<. ;ption  5 +. m ($.0 7t.) +.* m (.0 7t.) ma<.  LIGHT%DUT+ TUBE AND COUPLER SCAFFOLDS    Non-Embossed  L8-%:6- T6; * C,674/ S322,4: P,- S738 !5ased on 46.7 mm 8.&. 7.9 mm wall thickness :y ; 97< *=mm9 !74 ksi" steel tubing" "PT%"& 5  LIGHT%DUT+ TUBE AND COUPLER SCAFFOLDS  +arger post spacing may be used if $ustified by structural calculations or load test submitted for review per (.I. 6.>>? along with material tensile=yield stress test reports for the specific scaffold tubing to be used.   All light2duty tube @ coupler scaffolds may have a ma,imum of three working levels in use at any one time only when there are no additional levels where platform units are installed. %he ma,imum total number of levels that can be planked at one time depends on the number of working levels simultaneously used by workers. %he ma,imum uniformly distributed load on each working level shall be !=0 18m= (!.= 1Nm=) (=5 4;.2-=). Maei'ht :e9els :e9els  + ! %* m. (+5 7t.)   %* m. (+5 7t.) % * m. (!+ 7t.) +ight2duty%tube @ coupler scaffolds reuiring more than the above working or planked levels or over the ma,imum heights shown in the table shall be classified as a Special Scaffold and shall be properly designed and reviewed per (.I. 6.>>?. Preferably a properly designed system scaffold should be used instead of tube @ coupler construction for scaffolds ,@/ "# m. (!=5 2-.) -344  1#%1-T0 T=# A& $"P#! /$AFF"/  MEDIUM-DUTY LOADING   1#%1-T0 T=# A& $"P#! /$AFF"/  7ll tubing used to construct edium!duty and more hea"ily loaded tube < coupler scaffolds shall be embossed.  a&imum post spacing for medium!duty scaffolds "PT%"& '  1#%1-T0 T=# A& $"P#! /$AFF"/  a&imum post spacing for medium!duty scaffolds "PT%"& 5 VII. TUBE AND COUPLER SCAFFOLDS  MEDIUM%DUT+ TUBE AND COUPLER SCAFFOLDS  *arger post spacing may be used if ustified by structural calculations or load test submitted for re"iew per G.I. ,.991) along with material tensile$yield stress test reports for the specific scaffold tubing to be used.  edium!duty tube < coupler scaffolds may ha"e a ma&imum of two wor#ing le"els in use at any one time only when there are no additional le"els where platform units are installed. owe"er) when only one wor#ing le"el is being used) a ma&imum of additional 6 le"els may be plan#ed if they are not being used at the same time. 0he ma&imum distributed load on each wor#ing le"el shall not e?ceed 593 k4;m5  )5.9 k&;m5+ )63 lb.;ft5+. Maei'ht +  %* m. (+5 7t.) *ight!duty tube < coupler scaffolds reuiring more than the abo"e wor#ing   $ m. (* 7t.) or plan#ed le"els) or o"er the ma&imum heights shown in the table) shall be classified as a pecial caffold and shall be properly designed and re"iewed per G.I. ,.991. ;referably) a properly designed system scaffold should be used instead of tube < coupler construction for scaffolds over 7( m. )'56 ft.+ tall  MOBILE AND TOWER SCAFFOLD CONSTRUCTION  obile and tower scaffolds shall be plumb) le"el) and suare and be hori/ontally and "ertically braced +in both directions- by diagonal braces.  ;lan +hori/ontal- bracing shall be installed at the base) at the top) and at least e"ery third lift of all mobile and tower scaffolds to pre"ent rac#ing +twisting-.  1"=%# A& T"C#! /$AFF" $"&/T!$T%"&  0ube < coupler mobile and tower scaffolds that are one bay lon4 and one bay wide )only 9 posts+: :;A?@NG :i'ht/d3ty :i'ht/d3ty MA. ,;ST S,A@NG @N B;T> ?@1T@;N (only $ post)  m. (.57t) ( 7 ) ST: TB@NG MANCAT1 ? D MB;S? AS ,1 S,@C@AT@;N S A??E: 1F@1MNT " ;N?@T@;N Yes  sed only 7or personnel access and inspection  At least to e23ally spaced 4oard 4earers shall 4e 3sed  ppermost ork plat7orm hei'ht shall not e