CBC · California Building Code

Which standards govern cold‑formed steel design (AISI/ASCE)?

The CBC tells engineers to use AISI standards for cold‑formed steel: AISI S100 for general members, AISI S310 for diaphragms, AISI S240 for light‑frame systems (AISI S230 permitted only for qualifying 1–2 family prescriptive work), and AISI S400 where the code requires seismic detailing; cold‑formed stainless uses ASCE 8 (see §§2204–2206).

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Last reviewed: July 5, 2026

What the code requires — plain English

The California Building Code (CBC) directs designers to use the AISI and ASCE cold‑formed steel standards for design and detailing. For general cold‑formed carbon and low‑alloy members use AISI S100; diaphragms follow AISI S310; cold‑formed stainless steel follows ASCE 8. Specific seismic and light‑frame rules (including when AISI S400 is required) are stated in the CBC sections below. See §2204, §2205 and §2206 for the controlling text.

Requirements in detail

Which standard applies to what

  • Cold‑formed carbon and low‑alloy structural members (not covered in later sections): design per AISI S100 — §2204.1.
  • Cold‑formed steel diaphragms: additional provisions of AISI S310 apply — §2204.1.
  • Cold‑formed stainless steel members: design per ASCE 8 — §2205.1.
  • Cold‑formed steel light‑frame construction (walls, floors, roofs, trusses, shear walls, diaphragms): design and installation per AISI S240 and CBC §2206.1 (with seismic subrules) — §2206.1.

Seismic-specific rules (what forces the use of AISI S400)

  • For cold‑formed steel seismic force‑resisting systems the CBC calls out two paths:
    • If using the R‑factor in ASCE 7 Table 12.2‑1 for CFS special bolted moment frames, design and detailing must follow AISI S400 — §2204.2.1.
    • Systems designed and detailed to AISI S100 may use the ASCE 7 R listed for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems” without also complying with AISI S400 — §2204.2.2.
  • For cold‑formed steel light‑frame construction the CBC prescribes:
    • Seismic Design Categories B and C: if the designer uses ASCE 7 Table 12.2‑1 R, the seismic system shall be designed per AISI S400, except the exception permitting the ASCE 7 “steel systems not specifically detailed…” R for systems designed per AISI S240 — §2206.1.1.1.
    • Seismic Design Categories D, E or F: seismic force‑resisting systems must be designed and detailed in accordance with AISI S400 — §2206.1.1.2.

Light‑frame prescriptive allowance (one‑ and two‑family)

Detached one‑ and two‑family dwellings and townhouses ≤ 3 stories may be built to the AISI S230 prescriptive method (subject to the limits in that standard) — §2206.1.2.

Table — decision‑relevant scenarios and code references

Scenario / Decision point Governing standard(s) Code Reference
General cold‑formed carbon/low‑alloy members AISI S100 §2204.1
Cold‑formed diaphragms AISI S310 (additional provisions) §2204.1
CFS special bolted moment frames using ASCE 7 R AISI S400 required §2204.2.1
CFS seismic systems using AISI S100 AISI S100 permitted; may use ASCE 7 “steel systems not specifically detailed…” R §2204.2.2
Cold‑formed stainless steel members ASCE 8 §2205.1
Cold‑formed light‑frame systems (walls, floors, roofs, trusses) AISI S240 (with seismic subrules pointing to AISI S400 where required) §2206.1, §2206.1.1.1, §2206.1.1.2
Prescriptive single/two‑family framing AISI S230 (prescriptive) §2206.1.2
Cutting/notching of framing members AISI S240 for structural; AISI S220 for nonstructural §2206.3, §2206.2

(Also note the CBC References list cites the specific AISI documents — AISI S100, S240, S230, S310 and S400 — which are the normative sources called-out by these §§.)

Exceptions & special cases

  • OSHPD (health facility) provisions modify application: OSHPD requires cold‑formed steel structures be designed per AISI S100 and AISI S400 and specifically disallows cold‑formed special bolted moment frames for OSHPD projects — see the OSHPD note in §2204.2.
  • The CBC explicitly allows an exception in §2206.1.1.1: the ASCE 7 R for “Steel systems not specifically detailed for seismic resistance…” is allowed for systems designed per AISI S240, so those systems need not be designed to AISI S400 when that exception applies. Carefully confirm the exact ASCE 7 R used and the system detailing before applying the exception.
  • Prescriptive AISI S230 is limited to one‑ and two‑family dwellings and townhouses and is subject to the limits and applicability statements inside S230 itself; do not apply S230 beyond those limits — §2206.1.2.

If you need additional OSHPD/DSA‑SS modifications (state agency jurisdictions), the CBC contains bracketed agency notes and alternations; check the agency‑specific CBC subsections for limits (e.g., restrictions on prescriptive methods or special assemblies).

Common mistakes

  • Applying AISI S100 (member spec) as the governing standard for light‑frame construction when the CBC requires AISI S240 for that framing class — check §2206.1.
  • Assuming AISI S100 is sufficient for seismic force‑resisting systems in higher seismic categories (D–F) — the CBC requires AISI S400 for those SDs (§2206.1.1.2).
  • Using the ASCE 7 R value for a system without confirming whether the CBC forces AISI S400 detailing (e.g., special bolted moment frames under §2204.2.1).
  • Overusing the prescriptive AISI S230 method beyond its stated applicability (one‑ and two‑family/townhouse limits) — see §2206.1.2.
  • Forgetting diaphragm rules: cold‑formed diaphragms have additional AISI S310 provisions called for by §2204.1 (diaphragm design is not automatically covered by S100).

Worked example — applying the rule with numbers

Scenario: A 3‑unit, 2‑story townhouse (detached style), each unit under 3 stories above grade plane, located in a non‑high seismic area assigned to Seismic Design Category B. The owner wants to use cold‑formed steel light‑frame construction.

Step 1 — Determine applicable CBC section: light‑frame cold‑formed construction → §2206.1.
Step 2 — Check prescriptive allowance: the building is detached townhouse ≤ 3 stories — AISI S230 prescriptive method is permitted for one‑ and two‑family dwellings and townhouses subject to S230 limits; confirm the project meets S230 limits (geometry, exposures, wind, snow) — §2206.1.2.
Result A — If the project meets S230 applicability, use AISI S230 prescriptive tables for member sizes, thickness and connectors. (CBC §2206.1.2 permits that path.)

Alternate path (engineered): If the designer chooses an engineered approach using ASCE 7 seismic design (and uses the ASCE 7 R values from Table 12.2‑1), then for SD B the CBC requires design and detailing in accordance with AISI S400 unless the system qualifies for the AISI S240 exception; so the designer must either: (a) design and detail per AISI S400, or (b) design per AISI S240 and use the CBC exception language to utilize the ASCE 7 “steel systems not specifically detailed…” R — §2206.1.1.1.

Note: For a 2‑story townhouse where prescriptive S230 applies, you would typically select member thicknesses and grades directly from S230 tables (S230 references are in the CBC referenced standards list). Always confirm corrosion protection, fastening, and notching rules per AISI S240/S220 as cross‑referenced by the CBC.

Related provisions

  • §2204 — Cold‑formed steel (general rules, seismic rules)
  • §2204.1 — General design: AISI S100; diaphragms AISI S310
  • §2204.2, §2204.2.1, §2204.2.2 — Seismic design and AISI S400/AISI S100 options
  • §2205.1 — Cold‑formed stainless steel: ASCE 8 required
  • §2206.1 — Cold‑formed steel light‑frame construction: AISI S240 required for framing
  • §2206.1.1.1 — Seismic categories B & C and AISI S400/AISI S240 exception
  • §2206.1.1.2 — Seismic categories D–F: AISI S400 required
  • §2206.1.2 — Prescriptive framing (AISI S230) for one‑ and two‑family dwellings/townhouses
  • §2206.2 — Nonstructural members: AISI S220
  • §2206.3 — Cutting and notching rules reference AISI S240 / AISI S220

Code references

Grounded in the retrieved California Building Code — click a citation to read the verbatim passage:

  • CBC § 2202.4.5 High relevance — show source text

    2202.4.5 Modifications to AISC 358 Chapter 15. The DuraFuse Frames (DFF) bolted moment connection shall be permitted, provided: 1. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 2. DFF connection bolts shall not slip under wind design demand loads. The connection shall be designed to prevent slip using AISC 360 Equation J3-4, where the slip resistance is taken to be 0.3. 3. Beam flange width-to-thickness ratio shall satisfy AISC 341 Table D1.1b. 4. The beam weight shall be limited to a maximum of 232 pounds per foot (345 kg/m).

    SECTION 2203—STRUCTURAL STAINLESS STEEL

    2203.1 General. The design, manufacture and erection of austenitic and duplex structural stainless steel shall be in accordance with AISC 370.

    SECTION 2204—COLD-FORMED STEEL

    2204.1 General. The design of cold-formed carbon and low-alloy steel structural members not covered in Sections 2206 through 2209 shall be in accordance with AISI S100. The design of cold-formed steel diaphragms shall be in accordance with additional provisions of AISI S310 as applicable. Where required, the seismic design of cold-formed steel structures shall be in accordance with the additional provisions of Section 2204.2.

    2204.2 Seismic design. The design and detailing of cold-formed steel seismic force-resisting systems shall be in accordance with Sections 2204.2.1 and 2204.2.2, as applicable.

    [OSHPD 1R, 2 & 5] Cold-formed steel structures shall be designed and detailed in accordance with the requirements of AISI S100 and AISI S400. Cold-formed steel special bolted moment frames are not permitted by OSHPD.

    2204.2.1 CFS special bolted moment frames. Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1, is used for the design of cold-formed steel special bolted moment frames, the structures shall be designed and detailed in accordance with the requirements of AISI S400.

    2204.2.2 Cold-formed steel seismic force-resisting systems. The response modification coefficient, R, designated in ASCE 7 Table 12.2-1 for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems" shall be permitted for systems designed and detailed in accordance with AISI S100. Such systems need not be designed and detailed in accordance with AISI S400.

    SECTION 2205—COLD-FORMED STAINLESS STEEL

    2205.1 General. The design of cold-formed stainless steel structural members shall be in accordance with ASCE 8.

    [OSHPD 1R, 2 & 5] Modify AISI S100 Chapter J (Connections and Joints, Section J7.2) by the following: Power-actuated fastener allow- able design strength shall not exceed that permitted in the evaluation report qualified by ICC AC 70 or ASCE 7, Section 13.4.5.

    SECTION 2206—COLD-FORMED STEEL LIGHT-FRAME CONSTRUCTION

  • CBC § 1609.1.1 High relevance — show source text

    AISI S230—2019: North American Standard for Cold-formed Steel Framing—Prescriptive Method for One and Two Family Dwellings, 2019 Edition

    1609.1.1, 1609.1.1.1, 2204.1, 2206.1.2

    AISI S240—20: North American Standard for Cold-Formed Steel Structural Framing, 2020 Edition Table 1404.5.2.1, Table 1404.5.2.2, Table 1705A.2.1, 1709A.2.9, 2206.1, 2206.1.1.1, 2206.1.3.3, 2206.3, 2212.1, 2206A.2, Table 2506.2, Table 2507.2

    AISI S310—20 w/S1—22: North American Standard for the Design of Profiled Steel Diaphragm Panels, with Supplement 1, 2022 Edition

    2204.1, 2208.1

    AISI S400—20: North American Standard for Seismic Design of Cold-formed Steel Structural Systems, 2020 Edition

    2204.2.1, 2204.2.2, 2206.1.1.1, 2206.1.1.2 , 2215A.4.3

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    REFERENCED STANDARDS

    ALI Automotive Lift Institute, Inc., P.O. Box 85, Cortland, NY 13045

    ALI ALCTV—2022: Standard for Automotive Lifts—Safety Requirements for Construction, Testing and Validation (ANSI)

    Table 3001.3

    AMCA Air Movement and Control Association International, 30 West University Drive, Arlington Heights, IL 60004

    ANSI/AMCA 540—23: Test Method for Louvers Impacted by Wind Borne Debris

    1609.2.1

    ANSI American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036

    A13.1—2020: Scheme for the Identification of Piping Systems

    415.11.7.5

    A108.1A—17: Installation of Ceramic Tile in the Wet-set Method, with Portland Cement Mortar

    2103.2.3

    A108.1B—17: Installation of Ceramic Tile on a Cured Portland Cement Mortar Setting Bed with Dry-set or Latex-Portland Cement

    Mortar

    2103.2.3

    A108.4—19: Installation of Ceramic Tile with Organic Adhesives or Water-cleanable Tile-setting Epoxy Adhesive

    2103.2.3.6

    A108.5—21: Setting of Ceramic Tile with Dry-Set Cement Mortar, Modified Dry-Set Cement Mortar, EGP (Exterior Glue Plywood) Modified Dry-Set Cement Mortar, or Improved Modified Dry-Set Cement Mortar

    2103.2.3.1, 2103.2.3.2

    A108.6—99 (Reaffirmed 2019): Installation of Ceramic Tile with Chemical Resistant, Water Cleanable Tile-Setting and -Grouting Epoxy

    2103.2.3.3

  • CBC § 2204.2.1 High relevance — show source text

    [OSHPD 1R, 2 & 5] Cold-formed steel structures shall be designed and detailed in accordance with the requirements of AISI S100 and AISI S400. Cold-formed steel special bolted moment frames are not permitted by OSHPD.

    2204.2.1 CFS special bolted moment frames. Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1, is used for the design of cold-formed steel special bolted moment frames, the structures shall be designed and detailed in accordance with the requirements of AISI S400.

    2204.2.2 Cold-formed steel seismic force-resisting systems. The response modification coefficient, R, designated in ASCE 7 Table 12.2-1 for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems" shall be permitted for systems designed and detailed in accordance with AISI S100. Such systems need not be designed and detailed in accordance with AISI S400.

    SECTION 2205—COLD-FORMED STAINLESS STEEL

    2205.1 General. The design of cold-formed stainless steel structural members shall be in accordance with ASCE 8.

    [OSHPD 1R, 2 & 5] Modify AISI S100 Chapter J (Connections and Joints, Section J7.2) by the following: Power-actuated fastener allow- able design strength shall not exceed that permitted in the evaluation report qualified by ICC AC 70 or ASCE 7, Section 13.4.5.

    SECTION 2206—COLD-FORMED STEEL LIGHT-FRAME CONSTRUCTION

    2206.1 Structural framing. For cold-formed steel light-frame construction, the design and installation of the following structural framing systems, including their members and connections, shall be in accordance with AISI S240, and Sections 2206.1.1 through 2206.1.3, as applicable:

    1. Floor and roof systems.

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    STEEL

    1. Structural walls.

    2. Shear walls, strap-braced walls and diaphragms that resist in-plane lateral loads.

    3. Trusses.

    2206.1.1 Seismic requirements for cold-formed steel structural systems. The design of cold-formed steel light-frame construction to resist seismic forces shall be in accordance with the provisions of Section 2206.1.1.1 or 2206.1.1.2, as applicable.

    2206.1.1.1 Seismic Design Categories B and C. Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1 is used for the design of cold-formed steel light-frame construction assigned to Seismic Design Category B or C, the seismic force-resisting system shall be designed and detailed in accordance with the requirements of AISI S400.

    Exception: The response modification coefficient, R, designated for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems” in ASCE 7, Table 12.2-1, shall be permitted for systems designed and detailed in accordance with AISI S240 and need not be designed and detailed in accordance with AISI S400.

  • CBC § 2202.4.4 High relevance — show source text

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    14. Bolted sideplate connections used on heavy-shallow frame beams for beams greater than 200 plf and shallower than 24 inches (610 mm) in depth shall be considered as an alternative system. 15. Skewed beams shall utilize the link-beam fabrication method with CJP welded splices for skew angles. The skew angle shall be less than 15 degrees. 16. For two-sided bolted sideplate connections sharing the same side plates at the same height and depth across the column, the vertical offset in the beams shall not exceed 10 inches (254 mm).

    2202.4.4 Modifications to AISC 358 Chapter 12. The Simpson Strong-Tie (SST) Strong Frame bolted moment connection shall be permitted, provided: 1. Only T-stub yield links are permitted. End plate yield links are not permitted. 2. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 3. Beam flange width-to-thickness ratio shall satisfy AISC 341 Table D1.1b. 4. Yield-Link stem-to-beam flange connection bolts shall not slip under wind design demand loads. Yield-Link stem-to-beam flange connection shall be designed to prevent slip using AISC 360 Equation J3-4, where the slip resistance, μ , is taken to be 0.3.

    5. Double shear plate connection is permitted to increase connection axial capacity for collector loads. A partial joint penetra- tion (PJP) groove weld for second shear plate is permissible due to space restrictions.

    2202.4.5 Modifications to AISC 358 Chapter 15. The DuraFuse Frames (DFF) bolted moment connection shall be permitted, provided: 1. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 2. DFF connection bolts shall not slip under wind design demand loads. The connection shall be designed to prevent slip using AISC 360 Equation J3-4, where the slip resistance is taken to be 0.3. 3. Beam flange width-to-thickness ratio shall satisfy AISC 341 Table D1.1b. 4. The beam weight shall be limited to a maximum of 232 pounds per foot (345 kg/m).

    SECTION 2203—STRUCTURAL STAINLESS STEEL

    2203.1 General. The design, manufacture and erection of austenitic and duplex structural stainless steel shall be in accordance with AISC 370.

    SECTION 2204—COLD-FORMED STEEL

    2204.1 General. The design of cold-formed carbon and low-alloy steel structural members not covered in Sections 2206 through 2209 shall be in accordance with AISI S100. The design of cold-formed steel diaphragms shall be in accordance with additional provisions of AISI S310 as applicable. Where required, the seismic design of cold-formed steel structures shall be in accordance with the additional provisions of Section 2204.2.

    2204.2 Seismic design. The design and detailing of cold-formed steel seismic force-resisting systems shall be in accordance with Sections 2204.2.1 and 2204.2.2, as applicable.

  • CBC § 2202A.5.2 High relevance — show source text

    2202A.5.2 Section D2. Modify Section D2.6c(b)(2) as follows:

    (2) The moment calculated using the load combinations of the applicable building code, including the amplified seismic load, provided the connection or other mechanism within the column base is designed to have the ductility necessary to accommodate the column base rotation resulting from the design story drift.

    2202A.6 Modifications to AISC 358. [DSA-SS]

    2202A.6.1 Modifications to AISC 358 Chapter 10. [DSA-SS] Steel and concrete ConXtech ConXL composite special moment frame connections shall be permitted, provided: 1. Beams are provided with reduced beam sections (RBS); 2. Web extension to beam web two-sided fillet welds are sized to develop expected strength of the beam web and shall not be less than a [1] / 4 inch fillet weld; and 3. The built-up box column wall thickness shall not be less than 1.25 inches and the HSS column wall thickness shall not be less than [1] / 2 inch.

    SECTION 2203 A —STRUCTURAL STAINLESS STEEL

    2203 A .1 General. The design, manufacture and erection of austenitic and duplex structural stainless steel shall be in accordance with AISC 370.

    SECTION 2204 A —COLD-FORMED STEEL

    2204 A .1 General. The design of cold-formed carbon and low-alloy steel structural members not covered in Sections 2206 A through 2209 A shall be in accordance with AISI S100. The design of cold-formed steel diaphragms shall be in accordance with additional provisions of AISI S310 as applicable.

    SECTION 2205 A —COLD-FORMED STAINLESS STEEL

    2205 A .1 General. The design of cold-formed stainless steel structural members shall be in accordance with ASCE 8.

    SECTION 2206 A —COLD-FORMED STEEL LIGHT-FRAME CONSTRUCTION

    2206 A .1 Structural framing. For cold-formed steel light-frame construction, the design and installation of the following structural framing systems, including their members and connections, shall be in accordance with AISI S240, and Sections 2206 A .1.1 through 2206 A .1.3, as applicable:

    1. Floor and roof systems.

    2. Structural walls.

    3. Shear walls, strap-braced walls and diaphragms that resist in-plane lateral loads.

    4. Trusses.

    2206 A .1.1 Seismic requirements for cold-formed steel structural systems. The design of cold-formed steel light-frame construction to resist seismic forces shall be in accordance with the provisions of Section 2206 A .1.1.1 or 2206 A .1.1.2, as applicable.

    2206 A .1.1.1 Seismic Design Categories B and C. Not permitted by DSA-SS and OSHPD.

  • CBC § 1.3 High relevance — show source text

    332—20: Residential Code Requirements for Structural Concrete

    R402.2, R403.1, R404.1.3, R404.1.3.4, R404.1.4.2, R506.1

    AISI American Iron and Steel Institute 25 Massachusetts Avenue, NW Suite 800 Washington, DC 20001

    AISI S100—16 (2020) w/S2—20: North American Specification for the Design of Cold-Formed Steel Structural Members, 2016 Edition (Reaffirmed 2020), with Supplement 2, 2020 Edition

    R608.9.2, R608.9.3

    AISI S220—20: North American Standard for Cold-Formed Steel Nonstructural Framing, 2020 Edition

    R702.3.3

    AISI S230—19: North American Standard for Cold-Formed Steel Framing—Prescriptive Method for One and Two Family Dwellings, 2019 Edition

    R301.1.1, R301.2.1.1, R301.2.2.7, R301.2.2.8, R603.6, R603.9.4.1, R603.9.4.2, Figure R608.9(11), R608.9.2, R608.9.3, R608.10

    AISI S240—20: North American Standard for Cold-Formed Steel Structural Framing, 2020 Edition

    R505.1.3, R603.6, R702.3.3, R804.3.6

    ALI Automotive Lift Institute, Inc. PO Box 85 Cortland, NY 13045

    ALI ALCTV—2017: Standard for Automotive Lifts—Safety Requirements for Construction, Testing and Validation (ANSI)

    R317.7

    ANSI American National Standards Institute 25 West 43rd Street, 4th Floor New York, NY 10036

    A108.1A—17: Installation of Ceramic Tile in the Wet-Set Method, with Portland Cement Mortar

    R702.4.1

    2025 CALIFORNIA RESIDENTIAL CODE 44-3

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    REFERENCED STANDARDS

    A108.1B—2017: Installation of Ceramic Tile on a Cured Portland Cement Mortar Setting Bed with Dry-Set or Latex Portland

    Cement Mortar

    R702.4.1

    A108.4—19: Installation of Ceramic Tile with Organic Adhesives or Water-cleanable Tile-setting Epoxy Adhesive

    R702.4.1

    A108.5—21: Setting of Ceramic Tile with Dry-Set Cement Mortar, Modified Dry-Set Cement Mortar, EGP (Exterior Glue Plywood) Modified Dry-Set Cement Mortar, or Improved Modified Dry-Set Cement Mortar

    R702.4.1

    A108.6—99 (R2019): Installation of Ceramic Tile with Chemical Resistant, Water Cleanable Tile-Setting and -Grouting Epoxy

    R702.4.1

    A108.11—18: Interior Installation of Cementitious Backer Units

    R702.4.1

    A118.1—19: American National Standard Specifications for Dry-Set Portland Cement Mortar

    R702.4.1

  • CBC § 722.5.2.2.1 High relevance — show source text

    ANSI/AISC 360—22: Specification for Structural Steel Buildings 722.5.2.2.1, 1604.3.3, 1705.2.1, 1705A.2.1, Table 1705A.2.1, 1705A.2.5, 2201A.5.1, 2202.1, 2202.2.1.1, 2204.4, 2204A.4, 2215.1.1, 2215A.1.2, 2215A.2.1

    ANSI/AISC 370—21: Specification for Structural Stainless Steel Buildings 1705.2.2, 1705.2.2, Table 1705A.2.1, 1705A.2.2, 2203.1

    AISI American Iron and Steel Institute, 25 Massachusetts Avenue, NW Suite 800, Washington, DC 20001

    AISI S100—16(2020) w/S2—20: North American Specification for the Design of Cold-Formed Steel Structural Members, 2016 Edition (Reaffirmed 2020), with Supplement 2, 2020 Edition

    1604.3.3, 1905.7.2, 2204, 2204.2.2, 2204A.1

    AISI S202—20: Code of Standard Practice for Cold-formed Steel Structural Framing, 2020 Edition

    2206.1.3.1, 2206.1.3.1

    AISI S220—20: North American Standard for Cold-Formed Steel Nonstructural Framing, 2020 Edition 2203.1, 2206.2, 2206.3, Table 2506.2, Table 2507.2

    AISI S230—2019: North American Standard for Cold-formed Steel Framing—Prescriptive Method for One and Two Family Dwellings, 2019 Edition

    1609.1.1, 1609.1.1.1, 2204.1, 2206.1.2

    AISI S240—20: North American Standard for Cold-Formed Steel Structural Framing, 2020 Edition Table 1404.5.2.1, Table 1404.5.2.2, Table 1705A.2.1, 1709A.2.9, 2206.1, 2206.1.1.1, 2206.1.3.3, 2206.3, 2212.1, 2206A.2, Table 2506.2, Table 2507.2

    AISI S310—20 w/S1—22: North American Standard for the Design of Profiled Steel Diaphragm Panels, with Supplement 1, 2022 Edition

    2204.1, 2208.1

    AISI S400—20: North American Standard for Seismic Design of Cold-formed Steel Structural Systems, 2020 Edition

    2204.2.1, 2204.2.2, 2206.1.1.1, 2206.1.1.2 , 2215A.4.3

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    REFERENCED STANDARDS

  • CBC § 1.1 High relevance — show source text

    SECTION 2205 A —COLD-FORMED STAINLESS STEEL

    2205 A .1 General. The design of cold-formed stainless steel structural members shall be in accordance with ASCE 8.

    SECTION 2206 A —COLD-FORMED STEEL LIGHT-FRAME CONSTRUCTION

    2206 A .1 Structural framing. For cold-formed steel light-frame construction, the design and installation of the following structural framing systems, including their members and connections, shall be in accordance with AISI S240, and Sections 2206 A .1.1 through 2206 A .1.3, as applicable:

    1. Floor and roof systems.

    2. Structural walls.

    3. Shear walls, strap-braced walls and diaphragms that resist in-plane lateral loads.

    4. Trusses.

    2206 A .1.1 Seismic requirements for cold-formed steel structural systems. The design of cold-formed steel light-frame construction to resist seismic forces shall be in accordance with the provisions of Section 2206 A .1.1.1 or 2206 A .1.1.2, as applicable.

    2206 A .1.1.1 Seismic Design Categories B and C. Not permitted by DSA-SS and OSHPD.

    2206 A .1.1.2 Seismic Design Categories D through F. In cold-formed steel light-frame construction assigned to Seismic Design Category D, E or F, the seismic force-resisting system shall be designed and detailed in accordance with AISI S400. The following additional requirements apply: 1. Cold-formed steel stud foundation plates or sills shall be bolted or fastened to the foundation or foundation wall in accordance with Section 2304.3.4, Item 2.

    2. Shear wall assemblies in accordance with Sections E5, E6 and E7 of AISI 400 are not permitted within the seismic force- resisting system of buildings.

    2206 A .1.2 Prescriptive framing. Not permitted by DSA-SS and OSHPD.

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    2206 A .1.3 Truss design. Cold-formed steel trusses shall comply with the additional provisions of Sections 2206 A .1.3.1. through 2206 A .1.3.3.

    Complete engineering analysis and truss design drawings shall accompany the construction documents submitted to the enforce- ment agency for approval. When load testing is required, the test report shall be submitted with the truss design drawings and engineering analysis to the enforcement agency.

  • CBC § 506.6 High relevance — show source text

    506.6T—17: Visual Shotcrete Core Quality Evaluation

    1908.1, 1908A.1, 1909.4

    548.15-20: Specification for Crack Repair by Epoxy Injection

    1911.2, 1911A.2

    550.5—18: Code Requirements for the Design of Precast Concrete Diaphragms for Earthquake Motions

    Table 1705.3

    ITG—7-09: Specification for Tolerances for Precast Concrete

    1901.7.2

    AISC American Institute of Steel, 130 East Randolph Street, Suite 2000, Chicago, IL 60601-6219

    ANSI/AISC 341—22: Seismic Provisions for Structural Steel Buildings 1705.13.1.1, 1705.13.1.2, 1705.14.1.1, 1705.14.1.2, Table 1705A.2.1, 1810.3.5.3.1, 2202.2.1.1, 2202.2.1.2, 2202.2.2, 2202A.5, 2205.3,

    2215.2

    ANSI/AISC 358—22: Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications Table 1705A.2.1, 2202.2.1, 2202.2.1.2, 2202.3, 2202A.3, 2202A.6, 2215.3, 2205A, 2205.4, 2206A.2, 2206.2.1

    ANSI/AISC 360—22: Specification for Structural Steel Buildings 722.5.2.2.1, 1604.3.3, 1705.2.1, 1705A.2.1, Table 1705A.2.1, 1705A.2.5, 2201A.5.1, 2202.1, 2202.2.1.1, 2204.4, 2204A.4, 2215.1.1, 2215A.1.2, 2215A.2.1

    ANSI/AISC 370—21: Specification for Structural Stainless Steel Buildings 1705.2.2, 1705.2.2, Table 1705A.2.1, 1705A.2.2, 2203.1

    AISI American Iron and Steel Institute, 25 Massachusetts Avenue, NW Suite 800, Washington, DC 20001

    AISI S100—16(2020) w/S2—20: North American Specification for the Design of Cold-Formed Steel Structural Members, 2016 Edition (Reaffirmed 2020), with Supplement 2, 2020 Edition

    1604.3.3, 1905.7.2, 2204, 2204.2.2, 2204A.1

    AISI S202—20: Code of Standard Practice for Cold-formed Steel Structural Framing, 2020 Edition

    2206.1.3.1, 2206.1.3.1

  • CBC § 32.1. High relevance — show source text

    2213 A .1 General. The design and installation of stairs, ladders and guarding serving steel storage racks and industrial steel work platforms shall be in accordance with MHI ANSI/MH 32.1.

    SECTION 2214 A —STEEL CABLE STRUCTURES

    2214 A .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. Steel cables with glass or polymer fabric material acting as a tensile membrane struc- ture is an alternative system.

    SECTION 2215A—[DSA-SS] LIGHT MODULAR STEEL MOMENT FRAMES FOR PUBLIC ELEMENTARY AND SECONDARY SCHOOLS, AND COMMUNITY COLLEGES

    2215A.1 General.

    2215A.1.1 Configuration. Light modular steel moment frame buildings shall be constructed of factory-assembled modules comprising a single-story moment-resisting space frame supporting a floor and roof. Individual modules shall not exceed a width of 14 feet (4.25 m) nor a length of 72 feet (22 m). All connections of beams to corner columns shall be designed as moment-resisting in accordance with the criteria of Section 2215A.2. Modules may be stacked to form multistory structures not exceeding 35 feet or two stories in height. When stacked modules are evaluated separately, seismic forces on each module shall be distributed in accordance with Section 12.8.3 of ASCE 7, considering the modules in the stacked condition. See Section 2215A.2.5 of this code.

    2215A.1.2 Design, fabrication and erection. The design, fabrication and erection of light modular steel moment- frame buildings shall be in accordance with the AISC Specification for Structural Steel Buildings (ANSI/AISC 360) and the AISI North American Specifi- cation for the Design of Cold-Formed Steel Structural Members (AISI S100), as applicable, and the requirements of this section. The maximum dead load of the roof and elevated floor shall not exceed 25 psf and 50 psf (1197 Pa and 2394 Pa), respectively. The maxi- mum dead load of the exterior walls shall not exceed 45 psf (2155 Pa).

    2215A.2 Seismic requirements. In addition to the other requirements of this code, the design, materials and workmanship of light modular steel moment frames shall comply with the requirements of this section. The response modification coefficient R shall be equal to 3 [ 1] / 2 . C d and Ω 0 shall be equal to 3.0.

    2215A.2.1 Base materials. Beams, columns and connection materials shall be limited to those materials permitted under the AISC Specification for Structural Members (ANSI/AISC 360) and the AISI North American Specification for the Design of Cold-Formed Steel Structural Members (AISI S100). All columns shall conform with standard AISC 360 shapes.

    2215A.2.2 Beam-to-column strength ratio. At each moment-resisting connection the following shall apply:

     -------------------- S bi F ybi - ≥ 1.4  S cj F ycj

  • CBC § 2206.1 High relevance — show source text

    2206.1 Structural framing. For cold-formed steel light-frame construction, the design and installation of the following structural framing systems, including their members and connections, shall be in accordance with AISI S240, and Sections 2206.1.1 through 2206.1.3, as applicable:

    1. Floor and roof systems.

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    1. Structural walls.

    2. Shear walls, strap-braced walls and diaphragms that resist in-plane lateral loads.

    3. Trusses.

    2206.1.1 Seismic requirements for cold-formed steel structural systems. The design of cold-formed steel light-frame construction to resist seismic forces shall be in accordance with the provisions of Section 2206.1.1.1 or 2206.1.1.2, as applicable.

    2206.1.1.1 Seismic Design Categories B and C. Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1 is used for the design of cold-formed steel light-frame construction assigned to Seismic Design Category B or C, the seismic force-resisting system shall be designed and detailed in accordance with the requirements of AISI S400.

    Exception: The response modification coefficient, R, designated for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems” in ASCE 7, Table 12.2-1, shall be permitted for systems designed and detailed in accordance with AISI S240 and need not be designed and detailed in accordance with AISI S400.

    2206.1.1.2 Seismic Design Categories D through F. In cold-formed steel light-frame construction assigned to Seismic Design Category D, E or F, the seismic force-resisting system shall be designed and detailed in accordance with AISI S400.

    [OSHPD 1R, 2 & 5]: 1. Cold-formed steel stud foundation plates or sills shall be bolted or fastened to the foundation or foundation wall in accordance with Section 2304.3.4, Item 2.

    2. Shear wall assemblies in accordance with Sections E5, E6 and E7 of AISI S400 are not permitted within the seismic force- resisting system of buildings.

    2206.1.2 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.

    2206.1.3 Truss design. Cold-formed steel trusses shall comply with the additional provisions of Sections 2206.1.3.1. through 2206.1.3.3.

    [ OSHPD 1R, 2 & 5] Complete engineering analysis and truss design drawings shall accompany the construction documents submit- ted to the enforcement agency for approval. When load testing is required, the test report shall be submitted with the truss design drawings and engineering analysis to the enforcement agency.

  • CBC § 2210.1.1.1 High relevance — show source text

    2210.1.1.1 Structural steel. The design, fabrication and erection of structural steel shall be in accordance with Section 2202.

    2210.1.1.2 Cold-formed steel. The design of cold-formed carbon and low-alloy steel structural members shall be in accordance with Section 2204.

    2210.1.1.3 Steel joists. The design of steel joists shall be in accordance with Section 2207.

    2210.1.1.4 Steel cable. The design, fabrication and erection of steel cables, including related connections, shall be in accordance with Section 2214.

    2210.2 Seismic design. Where required, the seismic design, fabrication and erection of the structural steel seismic force-resisting system shall be in accordance with Section 2202.2.1 or 2202.2.2, as applicable.

    SECTION 2211—INDUSTRIAL BOLTLESS STEEL SHELVING

    2211.1 General. The design, testing and utilization of industrial boltless steel shelving shall be in accordance with MHI ANSI/MH 28.2. Where required by ASCE 7, the seismic design of industrial boltless steel shelving shall be in accordance with Chapter 15 of ASCE 7.

    SECTION 2212—INDUSTRIAL STEEL WORK PLATFORMS

    2212.1 General. The design, testing and utilization of industrial steel work platforms shall be in accordance with MHI ANSI/MH 28.3. Where required by ASCE 7, the seismic design of industrial steel work platforms shall be in accordance with Chapter 15 of ASCE 7.

    SECTION 2213—STAIRS, LADDERS AND GUARDING FOR STEEL STORAGE RACKS AND INDUSTRIAL STEEL WORK PLATFORMS

    2213.1 General. The design and installation of stairs, ladders and guarding serving steel storage racks and industrial steel work platforms shall be in accordance with MHI ANSI/MH 32.1.

    SECTION 2214—STEEL CABLE STRUCTURES

    2214.1 General. The design, fabrication and erection including related connections, and protective coatings of steel cables for buildings shall be in accordance with ASCE 19.

    [OSHPD 1R, 2 & 5] Steel cables with glass or polymer fabric material acting as a tensile membrane structure shall be considered as an alternative system.

    SECTION 2215 — ADDITIONAL REQUIREMENTS FOR COMMUNITY COLLEGES [DSA-SS/CC]

    2215.1 General.

    2215.1.1 Shear transfer at column base plate. Where the holes in column base plates are more than [1] / 8 inch (3 mm) larger than the anchor rods, as permitted by AISC 360, the anchor rods shall be designed for the induced bending stresses in combination with axial and shear stresses. Alternatively, shear lugs designed in accordance with ACI 318 Section 17.11 shall be permitted to transfer shear forces between column base plates and the supporting structure.

    2215.2 Modifications to AISC 341.

    2215.2.1 Section B5. Modify exception of Section B5.2(a) as follows:

Frequently asked questions

Which AISI standard do I use for a cold‑formed steel stud wall resisting lateral seismic forces?

Use AISI S240 for light‑frame studs; but if the system is part of a seismic force‑resisting system assigned to SD D–F or using certain ASCE 7 R values you will need AISI S400 detailing as required by §2206.1.1.2 and §2206.1.1.1.

Are diaphragms designed the same as beams under AISI S100?

No. The CBC calls for diaphragm provisions of AISI S310 in addition to AISI S100 for members; check §2204.1 for diaphragms.

Can I use AISI S230 for a 3‑story multifamily building?

No. AISI S230 prescriptive method in the CBC is limited to detached one‑ and two‑family dwellings and townhouses up to 3 stories per §2206.1.2; multifamily projects typically must use AISI S240 (engineered) or other applicable standards.

For cold‑formed stainless steel, which standard controls design?

ASCE 8 is the referenced design standard for cold‑formed stainless steel per §2205.1.

If I follow AISI S100, can I still use the ASCE 7 R‑factor?

Yes — CBC §2204.2.2 permits the ASCE 7 R for certain steel systems designed per AISI S100 (the ASCE 7 entry for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems”). Confirm the system classification before applying the R.

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