1 STEEL BUILDING EXTERIOR WALL INTERFACE ISSUES Rocky Mountain Steel Construction Association Structural Engineers Association of Colorado Structural Engineers

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STEEL BUILDINGEXTERIOR WALL

INTERFACE ISSUES

Rocky Mountain Steel Construction Association

Structural Engineers Association of Colorado

Structural Engineers Association of Colorado Steel Liaison Committee

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Past products from SEAC and RMSCA

1. AESS Guidelines – Prepared to assist in defining finishing and cost issues associated with AESS Steel

2. Input for the 2005 AISC Code of Standard Practice

3. Checklist for Structural Design Drawings

4. Pre-Detailing Meeting Agenda/Checklist

5. Current project: Improving the Shop Drawing Process

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INTERFACE ISSUES

ENGINEERING

TOLERANCE

CONSTRUCTABILITY

4STEEL BUILDING EXTERIOR WALL INTERFACE ISSUESSTEEL BUILDING EXTERIOR WALL INTERFACE ISSUES

consulting structural engineer = EORconsulting structural engineer = EOR

architect = AORarchitect = AOR


EOR’s primary role(s)EOR’s primary role(s)

•design team member•design team member

•assist the AOR with issues that involve engineering•assist the AOR with issues that involve engineering

•prime design team contact to the structural steel detailer•prime design team contact to the structural steel detailer

•insures the completed structure is safe and performs as expected•insures the completed structure is safe and performs as expected


information gatheringinformation gathering

AOR to determine skin typeAOR to determine skin type

AOR to coordinate application with the EORAOR to coordinate application with the EOR

EOR to insure structural adequacy at exterior wall interfaceEOR to insure structural adequacy at exterior wall interface

EOR to define connection between exterior wall and structural frameEOR to define connection between exterior wall and structural frame


what is the goal?what is the goal?

produce clear information on the design documentsproduce clear information on the design documentsassure all parties know who is responsible for what aspect of the design

assure all parties know who is responsible for what aspect of the design

meet with fabricators, erectors and exterior wall suppliersmeet with fabricators, erectors and exterior wall suppliers

insure that the GC understands the desired final expectationsinsure that the GC understands the desired final expectations


illustrate the eccentricities for which the steel frame is designed and/or the eccentricities for which the exterior wall must be designed

illustrate the eccentricities for which the steel frame is designed and/or the eccentricities for which the exterior wall must be designed


keeping the column line pushed out as far as possible could result in cost savings to the owner

keeping the column line pushed out as far as possible could result in cost savings to the owner


check pointscheck points

if possible, move the column line outwardif possible, move the column line outwardunderstand the exterior wall system and the desired interface with the structural frame

understand the exterior wall system and the desired interface with the structural frame

meet with fabricators, erectors and exterior wall suppliersmeet with fabricators, erectors and exterior wall suppliers

understand the tolerances involved with the projectunderstand the tolerances involved with the project




3 : the allowable deviation from a standard; especially : the range of variation permitted in maintaining a specified dimension

3 : the allowable deviation from a standard; especially : the range of variation permitted in maintaining a specified dimension


the range of variation permitted in maintaining a specified dimension


3 : the allowable deviation from a standard; especially :

3 : the allowable deviation from a standard; especially :







design team

may not know WHO

design team

may not know WHO


owner retains consultantsowner retains consultants

contract documents progress

contract documents progress

general contractor is retained

general contractor is retained

steel and exterior wall subs are secured

steel and exterior wall subs are secured


design team issues DD contract

documents

design team issues DD contract

documents

general contractor releases DD docs

for bid

general contractor releases DD docs

for bid

design team issues CD’sdesign team issues CD’s

general contractor has steel sub under contractgeneral contractor has

steel sub under contract

design team issues 100%

CD’s

design team issues 100%

CD’s

general contractor releases steel sub to

proceed with detailing

general contractor releases steel sub to

proceed with detailing



general

contractor detailing

approval

ste

el s

ub

s

tart

s

project begins

steel to be purchased

steel framecritical

path


steel framecritical

path??


submittal schedulesubmittal schedule approval dwgsapproval dwgsshop dwgsshop dwgsSub’s RFI’sSub’s RFI’serection schederection sched

coordinationcoordinationofofdesigndesign

must happenmust happen

of


clear

intent

predictable


leveling the playing fieldleveling the playing field

preparationpreparation



section 6.4section 6.4

“fabrication tolerance”

“fabrication tolerance”


preparationpreparationsteel tolerancesteel tolerancesweepsweeprollrollcambercamber




“installation of anchor

rods foundation bolts and

other embedded

items”

“installation of anchor

rods foundation bolts and

other embedded

items”




“structural steel frame tolerance”

“structural steel frame tolerance”




“erection tolerances”“erection

tolerances”





section 7.13.2

section 7.13.2

“in the design of steel structures, the owners designated representative for design shallshall provide for the necessary clearance and adjustments for material furnished by other trades to accommodate the mill tolerance, fabrication tolerances and erection tolerance as accepted in this Code for the Structural Steel frame.”

“in the design of steel structures, the owners designated representative for design shallshall provide for the necessary clearance and adjustments for material furnished by other trades to accommodate the mill tolerance, fabrication tolerances and erection tolerance as accepted in this Code for the Structural Steel frame.”



responsibilityresponsibilityresponsibilityresponsibility


suggested detailssuggested detailsdimensionsdimensionsand usage of tolerancesand usage of tolerances


•section 7.5 installation of anchor rods, foundation bolts and other embedded items

•section 7.5 installation of anchor rods, foundation bolts and other embedded items

-associated AISC tolerances--associated AISC tolerances-

•section 6.4 fabrication tolerance•section 6.4 fabrication tolerance

•section 7.13 erection tolerances•section 7.13 erection tolerances

•section 7.12 structural steel frame tolerances•section 7.12 structural steel frame tolerances



2005 AISC code of standard practice2005 AISC code of standard practice

-section 7.12--section 7.12-

“the accumulation of the mill tolerance and the fabrication tolerances shall not cause the erection tolerance to be exceeded”

“the accumulation of the mill tolerance and the fabrication tolerances shall not cause the erection tolerance to be exceeded”


2005 AISC code of standard practice2005 AISC code of standard practice

-section 7.13--section 7.13-

“erection tolerances shall be defined relative to the member working points and working lines”

“erection tolerances shall be defined relative to the member working points and working lines”



the more understanding the

design team has of the interface of the

structural frame to the exterior wall system, tolerance will become a useful tool and not a

problem for the construction team

the more understanding the

design team has of the interface of the

structural frame to the exterior wall system, tolerance will become a useful tool and not a

problem for the construction team






has or das will need to be

field installed

has or das will need to be

field installed

appropriate flange widthappropriate flange width

fewer restrictions at

the roof

fewer restrictions at

the roof


projectsuccessproject

success


•good communications•good communications

•heroes are rewarded if proper attention is given•heroes are rewarded if proper attention is given•review and understand structural framing system to control cost•review and understand structural framing system to control cost•select edge materials that will perform with the exterior wall system

•select edge materials that will perform with the exterior wall system


•edge materials that account for tolerance variations•edge materials that account for tolerance variations•clearly show all necessary offset dimensions on the design documents

•clearly show all necessary offset dimensions on the design documents•use the AISC code of standard practice, ASTM and experiences of the construction team

•use the AISC code of standard practice, ASTM and experiences of the construction team

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INTERFACE ISSUES

ENGINEERING

TOLERANCE

CONSTRUCTABILITY

51


INTERFACE ISSUES

ENGINEERING

TOLERANCE

CONSTRUCTABILITY


CONSTRUCTABILITYCONSTRUCTABILITY

•brief history of project evolution•brief history of project evolution

•EOR drawing process•EOR drawing process

•recommendations•recommendations





BRIEF HISTORY OF PROJECT EVOLUTION


PRIOR TO 1950’SPRIOR TO 1950’S

1. ARCHITECT – MASTER BUILDER1. ARCHITECT – MASTER BUILDER

2. DRAWINGS – DRAWN IN INK ON LINEN & VERY DETAILED

2. DRAWINGS – DRAWN IN INK ON LINEN & VERY DETAILED

3. STRUCTURE INCLUDED IN ARCHITECTURAL DRAWINGS

3. STRUCTURE INCLUDED IN ARCHITECTURAL DRAWINGS

4. BUILDING SHAPES – RECTANGULAR, 1-3 STORIES

4. BUILDING SHAPES – RECTANGULAR, 1-3 STORIES




PRIOR TO 1950’SPRIOR TO 1950’S

7. GC’S SELF PERFORMED ALL OF THE WORK7. GC’S SELF PERFORMED ALL OF THE WORK

5. EXTERIOR MATERIALS – LIMITED TO STONE, MASONRY, AND PUNCHED WOOD WINDOWS

5. EXTERIOR MATERIALS – LIMITED TO STONE, MASONRY, AND PUNCHED WOOD WINDOWS

6. FLOOR AND ROOF SYSTEMS – WOOD OR CONCRETE

6. FLOOR AND ROOF SYSTEMS – WOOD OR CONCRETE




1950’S – 1960’S1950’S – 1960’S

1. STRUCTURAL SYSTEMS EXPANDED TO INCLUDE STRUCTURAL STEEL, STEEL JOISTS AND PRECAST CONCRETE

1. STRUCTURAL SYSTEMS EXPANDED TO INCLUDE STRUCTURAL STEEL, STEEL JOISTS AND PRECAST CONCRETE

2. STRUCTURAL DRAWINGS BECAME SEPARATE DOCUMENTS

2. STRUCTURAL DRAWINGS BECAME SEPARATE DOCUMENTS




1950’S – 1960’S1950’S – 1960’S

3. GC’S STARTED BROKERING WORK OUT TO SUBCONTRACTORS

3. GC’S STARTED BROKERING WORK OUT TO SUBCONTRACTORS

4. STEEL SHOP DRAWING PREPARATION BY IN-HOUSE ENGINEERS

4. STEEL SHOP DRAWING PREPARATION BY IN-HOUSE ENGINEERS




1970’S1970’S

1. BEGINNING OF MORE COMPLEX EXTERIOR WALL SYSTEMS

1. BEGINNING OF MORE COMPLEX EXTERIOR WALL SYSTEMS

2. DRAWINGS PREPARED ON MYLAR AND PIN-BAR SYSTEM

2. DRAWINGS PREPARED ON MYLAR AND PIN-BAR SYSTEM

3. COMBINATION OF STRUCTURAL AND EXTERIOR WALL SYSTEMS INCREASED

3. COMBINATION OF STRUCTURAL AND EXTERIOR WALL SYSTEMS INCREASED




1980’S1980’S

1. ADVENT OF CAD1. ADVENT OF CAD

2. BUILDING COMPLEXITY SKYROCKETS2. BUILDING COMPLEXITY SKYROCKETS

3. MORE EXTERIOR WALL SYSTEM CHOICES3. MORE EXTERIOR WALL SYSTEM CHOICES




1980’S1980’S

4. GC LOYALTY TO SUBCONTRACTORS STARTS TO DIMINISH

4. GC LOYALTY TO SUBCONTRACTORS STARTS TO DIMINISH

5. EOR SELECTION SHIFTS FROM QUALIFICATION TO FEE BASIS

5. EOR SELECTION SHIFTS FROM QUALIFICATION TO FEE BASIS

6. STEEL SUBCONTRACTORS START CUTBACK OF SHOP DRAWING STAFF AND BEGIN TO OUTSOURCE

6. STEEL SUBCONTRACTORS START CUTBACK OF SHOP DRAWING STAFF AND BEGIN TO OUTSOURCE




1990’S1990’S

1. BUILDING SHAPES AND EXTERIOR SKINS FURTHER EVOLVE INTO UNTESTED CONSTRUCTION

1. BUILDING SHAPES AND EXTERIOR SKINS FURTHER EVOLVE INTO UNTESTED CONSTRUCTION

2. EOR & SUBCONTRACTOR SELECTION BASED ON LOW DOLLARS

2. EOR & SUBCONTRACTOR SELECTION BASED ON LOW DOLLARS

3. “GIVE & TAKE” ATMOSPHERE OF CONSTRUCTION BEGINS TO ERODE

3. “GIVE & TAKE” ATMOSPHERE OF CONSTRUCTION BEGINS TO ERODE




1990’S1990’S

4. GC LOYALTY TO SUBCONTRACTORS IS RARELY SEEN

4. GC LOYALTY TO SUBCONTRACTORS IS RARELY SEEN

5. COMPETITION FOR LOWER COST FORCES LESSER QUALITY DOCUMENTS

5. COMPETITION FOR LOWER COST FORCES LESSER QUALITY DOCUMENTS

6. TECHNOLOGY EXPLOSION LEAVES EXPERIENCE ON THE SIDELINE

6. TECHNOLOGY EXPLOSION LEAVES EXPERIENCE ON THE SIDELINE




1990’S1990’S

7. COORDINATION OF DOCUMENTS WITH OTHER TRADES WANES

7. COORDINATION OF DOCUMENTS WITH OTHER TRADES WANES

8. STEEL SUBCONTRACTORS OUTSOURCE MAJORITY OF SHOP DRAWING PREPARATION

8. STEEL SUBCONTRACTORS OUTSOURCE MAJORITY OF SHOP DRAWING PREPARATION




2000’S2000’S

1. SUBCONTRACTOR COMPETITION IS INTENSE, SO REPEAT WORK IS DIFFICULT TO OBTAIN

1. SUBCONTRACTOR COMPETITION IS INTENSE, SO REPEAT WORK IS DIFFICULT TO OBTAIN

2. TIGHT MARGINS FORCE LESS “GIVE & TAKE”

2. TIGHT MARGINS FORCE LESS “GIVE & TAKE”

3. SHOP DRAWINGS ARE DIFFICULT TO PREPARE

3. SHOP DRAWINGS ARE DIFFICULT TO PREPARE




2000’S2000’S

4. LOWER CONSULTANT FEES AND TIGHT SCHEDULES RESULT IN LESS COMPLETE DOCUMENTS

4. LOWER CONSULTANT FEES AND TIGHT SCHEDULES RESULT IN LESS COMPLETE DOCUMENTS

5. GC REACTION – CM, NEGOTIATE IN ORDER TO HELP CONTROL DESIGN & COST

5. GC REACTION – CM, NEGOTIATE IN ORDER TO HELP CONTROL DESIGN & COST

6. ARCHITECTURAL EXPERIENCE LEVEL IN PREPARING DOCUMENTS DROPS

6. ARCHITECTURAL EXPERIENCE LEVEL IN PREPARING DOCUMENTS DROPS




2000’S2000’S7. TIMELY, BUILDABLE INPUT FROM

ARCHITECT TO SER DROPS OFF RESULTING IN INCOMPLETE COORDINATION OF DRAWINGS

7. TIMELY, BUILDABLE INPUT FROM ARCHITECT TO SER DROPS OFF RESULTING IN INCOMPLETE COORDINATION OF DRAWINGS

8. MIX OF EXTERIOR WALL SYSTEMS INCREASES

8. MIX OF EXTERIOR WALL SYSTEMS INCREASES

9. EFFECTIVE COMMUNICATION TRADED FOR EMAIL

9. EFFECTIVE COMMUNICATION TRADED FOR EMAIL



EOR DRAWING PROCESSEOR DRAWING PROCESS

1. SCHEMATIC DRAWINGS PROVIDED BY ARCHITECT TO EOR

1. SCHEMATIC DRAWINGS PROVIDED BY ARCHITECT TO EOR

2. EOR FRAMES BUILDING2. EOR FRAMES BUILDING

3. TYPICAL EDGE CONDITIONS ARE DEVELOPED BY EOR BASED ON IDEAS BY ARCHITECT

3. TYPICAL EDGE CONDITIONS ARE DEVELOPED BY EOR BASED ON IDEAS BY ARCHITECT

4. AS ARCHITECTURAL DRAWINGS DEVELOP, EOR ADJUSTS STRUCTURAL DOCUMENTS

4. AS ARCHITECTURAL DRAWINGS DEVELOP, EOR ADJUSTS STRUCTURAL DOCUMENTS


RECOMMENDATIONSRECOMMENDATIONS1. EOR MUST ASSIST ARCHITECT WITH

CONSTRUCTABILITY ISSUES AS DOCUMENTS ARE DEVELOPED

1. EOR MUST ASSIST ARCHITECT WITH CONSTRUCTABILITY ISSUES AS DOCUMENTS ARE DEVELOPED

2. EOR SHOULD SEEK CONSTRUCTABILITY INPUT FROM AFFECTED TRADES AS DOCUMENTS ARE PREPARED


3. FABRICATOR SHOULD IDENTIFY CONSTRUCTABILITY ISSUES UPFRONT


4. THE GC MUST COORDINATE CONSTRUCTABILITY ISSUES BETWEEN TRADES






RECOMMENDATIONSRECOMMENDATIONS1. EOR MUST ASSIST ARCHITECT WITH

CONSTRUCTABILITY ISSUES AS DOCUMENTS ARE DEVELOPED

1. EOR MUST ASSIST ARCHITECT WITH CONSTRUCTABILITY ISSUES AS DOCUMENTS ARE DEVELOPED








RECOMMENDATIONSRECOMMENDATIONS

5. FABRICATOR MUST PARTICIPATE IN COORDINATION OF AFFECTED TRADES

5. FABRICATOR MUST PARTICIPATE IN COORDINATION OF AFFECTED TRADES

6. EOR & ARCHITECT NEED TO ACCOMMODATE CONSTRUCABILITY ISSUES THAT ARISE DURING CONSTRUCTION

6. EOR & ARCHITECT NEED TO ACCOMMODATE CONSTRUCABILITY ISSUES THAT ARISE DURING CONSTRUCTION

7. TIMELY PRE-CONSTRUCTION MEETINGS ARE ESSENTIAL

7. TIMELY PRE-CONSTRUCTION MEETINGS ARE ESSENTIAL

8. CONSULTANTS MUST GET FIELD EXPERIENCE

8. CONSULTANTS MUST GET FIELD EXPERIENCE



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ENGINEERING

TOLLERANCE

CONSTRUCTABILITY


INTERFACE ISSUES



82


INTERFACE ISSUES

ENGINEERING

TOLLERANCE

CONSTRUCTABILITY

83


INTERFACE ISSUES

ENGINEERING

TOLERANCE

CONSTRUCTABILITY


Documents

1 STEEL BUILDING EXTERIOR WALL INTERFACE ISSUES Rocky Mountain Steel Construction Association Structural Engineers Association of Colorado Structural Engineers