Steel

This chapter establishes requirements for the quality, design, fabrication, and erection of steel used structurally in buildings, including various steel types and their connections.

2201 — General

2201.1 Scope. The provisions of this chapter govern the quality, design, fabrication and erection of steel used structurally in buildings or structures.

2202 — Definitions

2202.1 Definitions. The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meaning shown herein.

STEEL CONSTRUCTION, COLD-FORMED. That type of construction made up entirely or in part of steel structural members cold formed to shape from sheet or strip steel such as roof deck, floor and wall panels, studs, floor joists, roofjoists and other structural elements.

STEEL JOIST. Any steel structural member of a building or structure made of hot-rolled or cold-formed solid or open-web sections, or riveted or welded bars, strip or sheet steel members, or slotted and expanded, or otherwise deformed rolled sections.

STEEL MEMBER, STRUCTURAL. Any steel structural member ofa building or structure consisting ofa rolled steel structural shape other than cold-formed steel, or steel joist members.

2203 — Identification and Protection

2203.1 Identification. Identification of structural steel members shall comply with the requirements contained in AISC 360. Identification of cold-formed steel members shall comply with the requirements contained in AISI S100. Identification of cold-formed steel light-frame construction shall also comply with the requirements contained in AISI S200. Other steel furnished for structural load-carrying purposes shall be properly identified for conformity to the ordered grade in accordance with the specified ASTM standard or other specification and the provisions of this chapter. Steel that is not readily identifiable as to grade from marking and test records shall be tested to determine conformity to such standards.

2203.2 Protection. Painting of structural steel members shall comply with the requirements contained in AISC 360. Painting of open-web steeljoists andjoist girders shall comply with the requirements of SjI Cj-1.0, SjI jG-1.1, SjI K-1.1 and SjI LH/DLH-1.1. Individual structural members and assembled panels of cold-formed steel construction shall be protected against corrosion in accordance with the requirements contained in AISI S100. Protection of cold-formed steel light-frame construction shall also comply with the requirements contained in AISI S200.

Worked example

Scenario: An architect is designing a new commercial building utilizing both hot-rolled structural steel beams and cold-formed steel studs for partition walls.

Explanation: Per Section 2203.1, the structural steel beams must be identified according to AISC 360, and the cold-formed steel studs must meet identification requirements of AISI S100, ensuring proper material verification on site.

2204 — Connections

2204.1 Welding. The details ofdesign, workmanship and technique for welding, inspection of welding and qualification of welding operators shall conform to the requirements of the specifications listed in Sections 2205, 2206, 2207, 2209 and 2210. Special inspection of welding shall be provided where required by Section 1704.

2204.2 Bolting. The design, installation and inspection of bolts shall be in accordance with the requirements of the specifications listed in Sections 2205, 2206, 2209 and 2210. Special inspection of the installation of high-strength bolts shall be provided where required by Section 1704.

2204.2.1 Anchor rods. Anchor rods shall be set accurately to the pattern and dimensions called for on the plans. The protrusion of the threaded ends through the connected material shall be sufficient to fully engage the threads of the nuts, but shall not be greater than the length of the threads on the bolts.

2204.2.1 Anchor rods. Anchor rods shall be set accurately to the pattern and dimensions called for on the plans. The protrusion of the threaded ends through the connected material shall be sufficient to fully engage the threads of the nuts, but shall not be greater than the length of the threads on the bolts.

Worked example

Scenario: A structural engineer is detailing welded connections for a moment frame in a steel building.

Explanation: The engineer must ensure that the design details, workmanship, technique for welding, and inspection of welding conform to the specifications listed in Sections 2205, 2206, 2207, 2209, and 2210, as well as providing special inspection if required by other code sections.

2205 — Structural Steel

2205.1 General. The design, fabrication and erection of structural steel for buildings and structures shall be in accordance with AISC 360. Where required, the seismic design of steel structures shall be in accordance with the additional provisions of Section 2205.2.

2205.2 Seismic requirements for steel structures. The design ofstructural steel structures to resist seismic forces shall be in accordance with the provisions of Section 2205.2.1 or 2205.2.2 for the appropriate seismic design category.

2205.2.1 Seismic Design Category A, B or C. Structural steel structures assigned to Seismic Design Category A, B or C shall be ofany construction permitted in Section 2205. An R factor as set forth in Section 12.2.1 of ASCE 7 for the appropriate steel system is permitted where the structure is designed and detailed in accordance with the provisions of AISC 341, Part I. Systems not detailed in accordance with the above shall use the R factor in Section 12.2.1 of ASCE 7 designated for "structural steel systems not specifically detailed for seismic resistance." 2205.2.2 Seismic Design Category D, E or F. Structural steel structures assigned to Seismic Design Category D, E or F shall be designed and detailed in accordance with AISC 341, Part I.

2205.2.1 Seismic Design Category A, B or C. Structural steel structures assigned to Seismic Design Category A, B or C shall be ofany construction permitted in Section 2205. An R factor as set forth in Section 12.2.1 of ASCE 7 for the appropriate steel system is permitted where the structure is designed and detailed in accordance with the provisions of AISC 341, Part I. Systems not detailed in accordance with the above shall use the R factor in Section 12.2.1 of ASCE 7 designated for "structural steel systems not specifically detailed for seismic resistance."

2205.2.2 Seismic Design Category D, E or F. Structural steel structures assigned to Seismic Design Category D, E or F shall be designed and detailed in accordance with AISC 341, Part I.

2205.3 Seismic requirements for composite construction. The design, construction and quality of composite steel and concrete components that resist seismic forces shall conform to the requirements of the AISC 360 and ACI 318. An Rfactor as set forth in Section 12.2.1 of ASCE 7 for the appropriate composite steel and concrete system is permitted where the structure

ture is designed and detailed in accordance with the provisions of AISC 341, Part II. In Seismic Design Category B or above, the design ofsuch systems shall conform to the requirements of AISC 341, Part II.

2205.3.1 Seismic Design Categories D, E and F. Composite structures are permitted in Seismic Design Categories D, E and F, subject to the limitations in Section 12.2.1 of ASCE 7, where substantiating evidence is provided to demonstrate that the proposed system will perform as intended by AISC 341, Part II. The substantiating evidence shall be subject to bUilding official approval. Where composite elements or connections are required to sustain inelastic deformations, the substantiating evidence shall be based on cyclic testing.

2205.3.1 Seismic Design Categories D, E and F. Composite structures are permitted in Seismic Design Categories D, E and F, subject to the limitations in Section 12.2.1 of ASCE 7, where substantiating evidence is provided to demonstrate that the proposed system will perform as intended by AISC 341, Part II. The substantiating evidence shall be subject to bUilding official approval. Where composite elements or connections are required to sustain inelastic deformations, the substantiating evidence shall be based on cyclic testing.

Worked example

Scenario: A design team is preparing construction documents for a five-story office building with a structural steel frame in a seismic zone.

Explanation: The design, fabrication, and erection of the structural steel must fully comply with AISC 360. Additionally, due to the seismic zone, the specific seismic design provisions of Section 2205.2 must be incorporated into the structural steel design.

2206 — Steel Joists

2206.1 General. The design, manufacture and use of open web steel joists and joist girders shall be in accordance with one of the following Steel joist Institute (Sjl) specifications:

Sjl Cj-1.0
Sjl K-1.1
Sjl LH/DLH-1.1
Sjl jG-1.1

Where required, the seismic design of buildings shall be in accordance with the additional provisions of Section 2205.2 or 2210.5.

2206.2 Design. The registered design professional shall indicate on the construction documents the steel joist and/or steel joist girder designations from the specifications listed in Section 2206.1 and shall indicate the requirements for joist and joist girder design, layout, end supports, anchorage, non-Sjl standard bridging, bridging termination connections and bearing connection design to resist uplift and lateral loads. These documents shall indicate special requirements as follows :

Special loads including: 1.1. Concentrated loads;1.2. Nonuniform loads;1.3. Net uplift loads;1.4. Axial loads;1.5. End moments; and1.6. Connection forces.
Special considerations including: 2.1. Profiles for nonstandard joist and joist girder configurations (standard joist and joist girder configurations are as indicated in the Sjl catalog);2.2. Oversized or other nonstandard web openings; and2.3. Extended ends.
Deflection criteria for live and total loads for non-Sjl standard joists.

1.1. Concentrated loads;1.2. Nonuniform loads;1.3. Net uplift loads;1.4. Axial loads;1.5. End moments; and1.6. Connection forces.

1.1. Concentrated loads;1.2. Nonuniform loads;1.3. Net uplift loads;1.4. Axial loads;1.5. End moments; and1.6. Connection forces.

2.1. Profiles for nonstandard joist and joist girder configurations (standard joist and joist girder configurations are as indicated in the Sjl catalog);2.2. Oversized or other nonstandard web openings; and2.3. Extended ends.

2.1. Profiles for nonstandard joist and joist girder configurations (standard joist and joist girder configurations are as indicated in the Sjl catalog);2.2. Oversized or other nonstandard web openings; and2.3. Extended ends.

2206.3 Calculations. The steeljoist andjoist girder manufacturer shall design the steel joists and/or steel joist girders in accordance with the current Sjl specifications and load tables to support the load requirements of Section 2206.2. The registered design professional may require submission of the steel joist and joist girder calculations as prepared by a registered design professional responsible for the product design. If requested by the registered design professional, the steel joist manufacturer shall submit design calculations with a cover letter bearing the seal and signature of the joist manufacturer's registered design professional. In addition to standard calculations under this seal and signature, submittal of the following shall be included:

Non-Sjl standard bridging details (e.g. for cantilevered conditions, net uplift, etc.) .
Connection details for: 2.1. Non-Sjl standard connections (e.g. flush-framed or framed connections);2.2. Field splices; and2.3. joist headers.

2.1. Non-Sjl standard connections (e.g. flush-framed or framed connections);2.2. Field splices; and2.3. joist headers.

2.1. Non-Sjl standard connections (e.g. flush-framed or framed connections);2.2. Field splices; and2.3. joist headers.

2206.4 Steeljoist drawings. Steeljoist placement plans shall be provided to show the steeljoist products as specified on the construction documents and are to be utilized for field installation in accordance with specific project requirements as stated in Section 2206.2. Steel placement plans shall include, at a minimum, the following:

Listing of all applicable loads as stated in Section 2206.2 and used in the design of the steeljoists andjoist girders as specified in the construction documents.
Profiles for nonstandard joist andjoist girder configurations (standardjoist andjoist girder configurations are as indicated in the Sjl catalog).
Connection requirements for: 3.1. joist supports;3.2. joist girder supports;3.3. Field splices; and3.4. Bridging attachments.
Deflection criteria for live and total loads for non-Sjl standard joists.
Size, location and connections for all bridging.
joist headers.

3.1. joist supports;3.2. joist girder supports;3.3. Field splices; and3.4. Bridging attachments.

3.1. joist supports;3.2. joist girder supports;3.3. Field splices; and3.4. Bridging attachments.

Steeljoist placement plans do not require the seal and signature ofthejoist manufacturer's registered design professional.

2206.5 Certification. At completion of manufacture, the steel joist manufacturer shall submit a certificate of compliance in accordance with Section 1704.2.2 stating that work was performed in accordance with approved construction documents and with Sjl standard specifications.

Worked example

Scenario: An architect specifies open web steel joists for the roof structure of a new warehouse.

Explanation: The design, manufacturing, and use of these open web steel joists and their joist girders must be in accordance with one of the Steel Joist Institute (SJI) specifications, ensuring they meet recognized industry standards for safety and performance.

2207 — Steel Cable Structures

2207.1 General. The design, fabrication and erection including related connections, and protective coatings of steel cables for buildings shall be in accordance with ASCE 19.

2207.2 Seismic requirements for steel cable. The design strength of steel cables shall be determined by the provisions of ASCE 19 except as modified by these provisions.

A load factor of 1.1 shall be applied to the prestress force included in T3 and T4 as defined in Section 3.12.
In Section 3.2.1, Item (c) shall be replaced with" 1.5 T3" and Item (d) shall be replaced with" 1.5 T4."

Worked example

Scenario: A specialized design firm is proposing a cable-stayed pedestrian bridge as part of a new park development.

Explanation: The design, fabrication, erection (including related connections), and protective coatings for all steel cables used in this structure must be in accordance with ASCE 19, which specifically addresses the requirements for such steel cable structures.

2208 — Steel Storage Racks

2208.1 Storage racks. The design, testing and utilization of industrial steel storage racks made of cold-formed or hot-rolled steel structural members, shall be in accordance with the RMI/ANSI MH 16.1. Where required by ASCE 7, the seismic design of storage racks shall be in accordance with the provisions of Section 15.5.3 of ASCE 7, except that items (1), (2) and (3) of Section 15.5.3 ofASCE 7 do not apply when the rack design satisfies RMI/ANSI MH 16.1.

Worked example

Scenario: An industrial facility plans to install new pallet racking systems made of cold-formed steel.

Explanation: The design, testing, and utilization of these industrial steel storage racks must comply with RMI/ANSI MH 16.1. If the project is located in a seismic area as required by ASCE 7, the seismic design of these racks must also follow the provisions of Section 15 of ASCE 7 (not fully detailed in this snippet).

2209 — Cold-formed Steel

2209.1 General. The design of cold-formed carbon and low-alloy steel structural members shall be in accordance with AISI S100. The design of cold-formed stainless-steel structural members shall be in accordance with ASCE 8. Cold-formed steel light-frame construction shall also comply with Section 2210.

2209.2 Steel decks. The design and construction of cold-formed steel decks shall be in accordance with this section.

2209.2.1 Composite slabs on steel decks. Composite slabs of concrete and steel deck shall be designed and constructed in accordance with ASCE 3. 2209.2.2 Noncomposite steel floor decks. Noncomposite steel floor decks shall be permitted to be designed and constructed in accordance with ANSI/SDI-NC1 .0, as modified in Section 2209.2.2.1. 2209.9.2.2.1 ANSI/SDI-NC1.0 Section 2.4Bl. Replace Section 2.4B1 of ANSI/SDI-NC1.0 with the following: General: The design of the concrete slabs shall be done in accordance with the ACI BUilding Code Requirements for Reinforced Concrete. The minimum concrete thickness above the top of the deck shall be 1½ inches (38 mm). 2209.2.3 Steel roof deck. Steel roof decks shall be permitted to be designed and constructed in accordance with ANSI/SBI-RD1.0.

2209.2.1 Composite slabs on steel decks. Composite slabs of concrete and steel deck shall be designed and constructed in accordance with ASCE 3.

2209.2.2 Noncomposite steel floor decks. Noncomposite steel floor decks shall be permitted to be designed and constructed in accordance with ANSI/SDI-NC1 .0, as modified in Section 2209.2.2.1.

2209.9.2.2.1 ANSI/SDI-NC1.0 Section 2.4Bl. Replace Section 2.4B1 of ANSI/SDI-NC1.0 with the following: General: The design of the concrete slabs shall be done in accordance with the ACI BUilding Code Requirements for Reinforced Concrete. The minimum concrete thickness above the top of the deck shall be 1½ inches (38 mm).

2209.9.2.2.1 ANSI/SDI-NC1.0 Section 2.4Bl. Replace Section 2.4B1 of ANSI/SDI-NC1.0 with the following:

General: The design of the concrete slabs shall be done in accordance with the ACI BUilding Code Requirements for Reinforced Concrete. The minimum concrete thickness above the top of the deck shall be 1½ inches (38 mm).

2209.2.3 Steel roof deck. Steel roof decks shall be permitted to be designed and constructed in accordance with ANSI/SBI-RD1.0.

Worked example

Scenario: A designer is specifying cold-formed steel members for the framing of an exterior wall system.

Explanation: If the members are made of carbon or low-alloy steel, their design must conform to AISI S100. If stainless steel members are used, ASCE 8 governs their design. If it is a light-frame construction, Section 2210 also applies.

2210 — Cold-formed Steel

2210.1 General. The design and installation of structural members and nonstructural members utilized in cold-formed steel light-frame construction where the specified minimum base steel thickness is between 0.0179 inches (0.455 mm) and 0.1180 inches (2.997 mm) shall be in accordance with AISI S200 and Sections 2210.2 through 2210.7, as applicable.

2210.2 Header design. Headers, including box and back-to-back headers, and double and single L-headers shall be designed in accordance with AISI S212 or AISI S100.

2210.3 Trusses.

2210.3.1 Design. Cold-formed steel trusses shall be designed in accordance with AISI S214, Sections 2210.3.1 through 2210.3.5 and accepted engineering practice. 2210.3.2 Truss design drawings. The truss design drawings shall conform to the requirements of Section B2.3 of AISI S214 and shall be provided with the shipment of trusses delivered to the job site. The truss design drawings shall include the details of permanent individual truss member restraint/bracing in accordance with Section B6 (a) or B6(c) of AISI S214 where these methods are utilized to provide restraint/bracing. 2210.3.3 Deferred submittals. AISI Section B4.2 shall be deleted. 2210.3.4 Trussses spanning 60 feet or greater. The owner shall contract with a registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for trusses with clear spans 60 feet (18 288 mm) or greater. Special inspection of trusses over 60 feet (18 288 mm) in length shall conform to Section 1704. 2210.3.5 Truss quality assurance. Trusses not part of a manufacturing process that provides requirements for quality control done under the supervision of a third-party quality control agency, shall be manufactured in compliance with Sections 1704.2 and 1704.3, as applicable.

2210.3.1 Design. Cold-formed steel trusses shall be designed in accordance with AISI S214, Sections 2210.3.1 through 2210.3.5 and accepted engineering practice.

2210.3.2 Truss design drawings. The truss design drawings shall conform to the requirements of Section B2.3 of AISI S214 and shall be provided with the shipment of trusses delivered to the job site. The truss design drawings shall include the details of permanent individual truss member restraint/bracing in accordance with Section B6 (a) or B6(c) of AISI S214 where these methods are utilized to provide restraint/bracing.

2210.3.3 Deferred submittals. AISI Section B4.2 shall be deleted.

2210.3.4 Trussses spanning 60 feet or greater. The owner shall contract with a registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for trusses with clear spans 60 feet (18 288 mm) or greater. Special inspection of trusses over 60 feet (18 288 mm) in length shall conform to Section 1704.

2210.3.5 Truss quality assurance. Trusses not part of a manufacturing process that provides requirements for quality control done under the supervision of a third-party quality control agency, shall be manufactured in compliance with Sections 1704.2 and 1704.3, as applicable.

2210.4 Wall stud design. Wall studs shall be designed in accordance with either AISI S211 or AISI S100.

2210.5 Floor and roof system design. Framing for floor and roof systems in buildings shall be designed in accordance with either AISI S210 or AISI S100.

2210.6 Lateral design. Light-frame shear walls, diagonal strap bracing that is part of a structural wall and diaphragms used to resist wind, seismic and other in-plane lateral loads shall be designed in accordance with AISI S213.

2210.7 Prescriptive framing. Detached one- and two-family dwellings and townhouses, less than or equal to three stories above grade plane, shall be permitted to be constructed in accordance with AISI S230 subject to the limitations therein.

Worked example

Scenario: A builder is using cold-formed steel studs with a base steel thickness of 0.033 inches for interior non-load-bearing walls.

Explanation: The design and installation of these cold-formed steel nonstructural members fall within the specified thickness range. Therefore, their design and installation must be in accordance with AISI S200 and the additional requirements outlined in Sections 2210.2 and subsequent subsections.

Frequently asked questions

What standards govern the identification of structural steel members?

Structural steel members must be identified in compliance with AISC 360, while cold-formed steel members follow AISI S100 requirements.

Which code applies to the design of structural steel for buildings?

The design, fabrication, and erection of structural steel must adhere to AISC 360, with additional seismic provisions from Section 2205.2 where applicable.

What are the requirements for cold-formed steel light-frame construction?

Cold-formed steel light-frame construction must comply with AISI S200 and specific provisions outlined in Section 2210, for base steel thicknesses between 0.0179 and 0.1180 inches.