Steel Specifications Unraveled

My notes from NASCC 2018: Steel Specifications Unraveled [N19]
(PDH# 61823) Date: 04/11/2018

Presented by Jon Beier, PE
SMBH Structural Engineering
Intended Audience:  Engineers, Architects
Track: Design & Analysis
Session video link.

Session Description:
Most steel construction projects include drawings and specifications. This session will review a typical steel specification and describe the various items that could be included in a steel specifications. Throughout the specification, there are numerous choices that need to be made which all relate to the specific project. Several of the choices will be discussed and information will be provided that will assist specifiers in determining which choices are right for their projects.

Presentation Goals

  • Learning Objective 1: Name the three parts of a typical Specification section.
  • Learning Objective 2: Evaluate the various options included in some of the common Division 5 sections.
  • Learning Objective 3: Explain the options for including LEED in the specifications.
  • Learning Objective 4: Explain the options for including Architecturally Exposed Structural Steel (AESS) in the specification.

Where do we start?

  • Format
    • MasterFormat
      • Managed by Construction Specifications Institute (CSI)
      • 50 Divisions with multiple sections
    • Book Specifications vs. General Notes
      • Which are you using?
      • If using both, make sure they agree!
      • If using general notes, they need to be more robust and detailed.
      • Public works projects typically require book specifications.
      • Having information in more than one place makes it more likely to have contradictions.
    • Which Sections – Division 5 Metals
      • 051200 – Structural Steel Framing
      • 052100 – Steel Joist Framing
      • 053100 – Steel Decking
      • 051213 – AESS
      • 054000, 055000, 055113, 316216
    • Who edits the specifications?
      • Option 1: Design engineer specific to project
      • Option 2: One spec writer in the office responsible for all projects

Typical Specification Parts

  • Three Parts
    • General
    • Products
    • Execution

Typical Specification: Part 1 – General

  • Summary of what’s included
    • Need to know what you’re using and what you are not
    • Try to edit your spec as late in the project as possible.
    • When you know have most information about the project
  • Related Requirements
    • Requires outside coordination
    • Example, you may need to ask what paint should be listed to match division 9
    • Create a checklist
  • Definitions
    • More critical in high seismic applications
    • Keep is simple where possible
    • The shorter the better
    • Remove extraneous information
  • LEED Requirements
    • May be best covered elsewhere
  • Submittals
    • Including shop drawings and delegated design requirements – make sure to include “signed and sealed” if intended
    • Special certifications – local, state or owner requirements
    • Domestic requirements
  • Quality Assurance
    • AISC Certification
    • Reference specifications and documents – AISC 303, AISC 341, AISC 360, Bolt Specification, AWS D1.1, SJI (joists) and SDI (deck).

 Typical Specification: Part 2 – Products

  • Performance Requirements
    • Types of connections, ASD or LRFD
  • Manufacturers / Materials
  • Coatings
    • Surface preparation
    • Required primer to match with division 9 coatings

 Typical Specification: Part 3 – Execution

  • Erection
  • Field Quality Control – Testing
    • Who hires testing agency. Clarify if hired by the owner.
    • How is this different than Special Inspections?
  • Protection and repairs

 Custom Items to Consider Adding to Your Specifications

  • Paint or surface preparation modifications
  • Installer or erector requirements
  • Steel sourcing requirements
  • Special owner requirements

051200 Structural Steel Framing

  • Quality Assurance
    • Fabricator Qualifications: A qualified fabricator that participates in the AISC Quality Certification Program and is designated an AISC-Certified Plant, Category STD [,or is accredited by the IAS Fabricator Inspection Program for Structural Steel (AC 172)].
    • Fabricator Qualifications: A qualified fabricator with no less than (10) years of successful experience in comparable installation projects and employing personnel skilled in the fabrication processes and operations indicated.
    • With second option will need to keep shop inspections in Part 2 (Source Quality Control)
  • Coordination of finishes
    • No finish
    • Standard primer
    • Special primer
    • Fireproofing / intumescent paint
    • Preparation
      • SSPC-SP
    • Reference sections – Section 9 or Division 9.
  • Surface Preparation
    • SSPC-SP 2, Hand Tool Cleaning
    • SSPC-SP 3, Power Tool Cleaning
    • SSPC-SP 7/NACE No. 4, Brush-off Blast Cleaning
    • SSPC-SP 11, Power Tool Cleaning to Bare Metal
    • SSPC-SP 14/NACE No. 3, Commercial Blast Cleaning
    • SSPC-SP 10/NACE No. 2, Near-White Blast Cleaning
    • SSPC-SP 5/NACE No. 1, White Metal Blast Cleaning
    • SSPC-SP 8, Pickling
    • Numbers are typically from least to most comprehensive, lowest to highest cost.
  • Galvanizing
    • ASTM A 123
    • Do not quench steel that is painted over galvanizing
    • Relief holes
      • Is plugging holes required?
      • Who is responsible? (galvanizer, contractor, etc.)
    • Seal welding to prevent rust leaking
  • Material Properties
    • W-Shapes [ASTM A992] or [ASTM A572, GR 50]
    • Plate and Bar [ASTM A36] or [ASTM A572, GR 50]
    • Cold-Formed Hollow Structural Sections [ASTM A500, GR B or C] or [ASTM A1085, Fy = 50 ksi]
    • Bolts ASTM [A307] [A325] [A490]
    • Anchor Rods ASTM F1554 {Gr. 36] [Gr. 55] [Gr. 105]
  • Tension Controlled Connections
    • ASTM A490 bolts
    • Turn-of-nut method
    • Tension-control, bolt-nut-washer assembly with splined end
    • Direct-tension indictors (DTI) – AST MF959, type 490 compressible washers
  • Other Items
    • Use non-metallic grout where grout is susceptible to moisture – typically use as a default

052100 Steel Joist Framing

  • Few issues with getting reputable manufacturers
  • Most joists will come from the same primary 3-4 manufacturers in the US
  • Certified by SJI
  • Structural Performance:
    • USE [ASD; data are given at service-load level] [LRFD; data are given at factored-load level].
    • Design Special joists to withstand design loads with live-load deflections no greater than the following:
      • Floor Joists: Vertical deflection of [1/360] [1/240] of the span
      • Roof Joists: Vertical deflection of [1/360] [1/240] of the span
      • Refer to table 1604.3 in IBC (2015) for deflection limits
    • Top chord extensions versus extended ends, call out the type
    • Camber Options
      • None
      • According to SJI’s specification (see SJI table 4.6-1)
      • As indicated
    • Primer
      • Standard primer is typical
    • Bridging
      • Typical to allow manufacturer to specify using SJI’s “specifications”
    • Ceiling extensions

0523100 Steel Decking

  • Similar to joists with respect to quality
  • Finishes
    • Prime-painted – which color?
    • Galvanized – G60 standard
    • Galvanized and shop-primed
  • Profile, depth and thickness
    • Typically “as indicated” on Drawings
    • Be sure to coordinate span conditions (simple span, double span, triple span)
  • Two things to look out for:
    • Yield strength
    • Un-shored spans
      • Specify minimums in Specifications or General Notes
    • Acoustical deck (regular and cellular)
      • Acoustical performance
      • Installing sound-absorbing insulation
        • If installed in factory, covered here
        • If installed in field, may be covered elsewhere
      • Protecting insulation to prevent exposure to weather
    • Piercing hanger tabs
      • Only use in a space that is conditioned below
      • Do not use in outdoor or exposed areas
        • Will lead to rusting and failure
      • Installation
        • Welding
          • Weld washers – required if less than 0.028” (typically 24 gauge and thinner)
        • Mechanical fasteners
        • Callout fastener spacing in Specifications or on Drawings

Other Sections – AESS

  • 051213 – Architecturally Exposed Structural Steel Framing
    • Chapter 10 of AISC 303-16 “Code of Standard Practice for Steel Buildings and Bridges”
    • Now being incorporated into specification software
    • Requires close coordination with Architect
    • See AISC Table
    • AESS covered in more detail in another session
  • 054000 Cold-Formed Metal Framing
  • 055000 Metal Fabrications
  • 05 Sections for Stairs, gratings and railings
  • 316216 Steel Piles

Unique Conditions

  • Weathering Steel – see 2018 NASCC Conference session
  • What is structural versus non-structural
    • Cantilevered stairs
    • Storm shelter shrouds

 Benefits of Specifications

  • Better informs contractor
  • Help in dispute resolution
  • Provides total picture of designer’s intent
  • Conveys owner’s expectations
  • In a bidding environment, keep the playing field level

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