1 Scope
NOTE This standard governs the materials, fabrication, and installation of cold-formed steel framing (CFSF) for buildings — both members that carry calculated structural loads and members that resist only wind or transverse loads as exterior cladding backup. (1.1)
NOTE Cold-formed steel is roll-formed at ambient temperature from galvanized sheet steel into C-shaped studs, U-shaped tracks, channels, hat sections, Z-sections, and proprietary built-up shapes. (1.2)
NOTE The same family of products spans a wide range of structural roles: bearing studs in load-bearing exterior walls of multi-family and mid-rise buildings, curtain-wall studs that span between primary structure and resist only wind, joists in floor and roof framing, and ceiling and soffit furring. (1.3)
NOTE A single project frequently uses members from all of these categories, sometimes adjacent to one another. (1.4)
1.5 The specifier shall be clear about which members are structural and which are non-structural, because the governing standard, the gauge minimum, the coating minimum, and the inspection regime differ between the two.
1.6 Structural cold-formed steel — load-bearing studs, curtain-wall studs designed for wind, joists, rafters, and any member whose failure would compromise the building's structural integrity — shall be governed by AISI S100, AISI S240, and where seismic demands apply, AISI S400.
1.6.1 Structural members shall be manufactured to ASTM A1003/A1003M, sized per the manufacturer's published section properties, and identified by Steel Stud Manufacturers Association (SSMA) designations.
1.6.2 Connections and field installation of structural members shall be inspected as structural work.
1.7 Non-structural cold-formed steel — partition studs and runners that support only gypsum board, suspended ceiling framing, soffit framing, and similar interior assemblies that carry no calculated load beyond the finish itself — shall be governed by AISI S220 and installed under ASTM C754.
1.7.1 Non-structural members may be furnished to ASTM C645, which permits thinner base metal and is the standard's expected minimum for interior partitions.
1.8.1 The specification and the contract drawings shall be read together: this specification governs how the framing is procured, fabricated, connected, and erected, and the contract drawings define what is built and where.
1.9 Interface Coordination
NOTE Cold-formed steel framing interfaces with several adjacent scopes, each governed by its own standard and coordinated here at the framing interface only. (1.9.1)
1.9.4 Open-web steel joists and joist girders shall be governed by Steel Joists. 1.9.5 Firestopping of penetrations through fire-resistance-rated assemblies framed with CFSF shall be governed by Firestopping. NOTE Jamb stud sizing for door openings is one of the most common field-condition errors. (1.9.7)
2 Referenced Standards
2.1 Materials, fabrication, and installation shall comply with the latest edition of each standard listed below as adopted by the Authority Having Jurisdiction.
2.2 Where conflicts exist between referenced standards, the more stringent requirement governs unless the Structural Engineer of Record (SER) or Architect of Record (AOR) directs otherwise in writing.
2.3 For structural cold-formed steel, the SER's design basis and general structural notes govern over default assumptions in this specification.
2.4 Standards List
| Standard |
Title |
| AISI S100-16 (R2020) |
North American Specification for the Design of Cold-Formed Steel Structural Members |
| AISI S220-20 |
North American Standard for Cold-Formed Steel Framing — Nonstructural Members |
| AISI S240-20 |
North American Standard for Cold-Formed Steel Structural Framing |
| AISI S400-20 |
North American Standard for Seismic Design of Cold-Formed Steel Structural Systems |
| AISI S202-20 |
Code of Standard Practice for Cold-Formed Steel Structural Framing |
| ASTM A1003/A1003M |
Steel Sheet, Carbon, Metallic- and Nonmetallic-Coated for Cold-Formed Framing Members |
| ASTM A653/A653M |
Steel Sheet, Zinc-Coated (Galvanized) by the Hot-Dip Process |
| ASTM A1058/A1058M |
Mechanical Testing of Steel Products — Metric |
| ASTM C645 |
Nonstructural Steel Framing Members |
| ASTM C754 |
Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products |
| ASTM C955 |
Load-Bearing (Transverse and Axial) Steel Studs, Runners (Tracks), and Bracing or Bridging for Screw Application of Gypsum Panel Products and Metal Plaster Bases |
| ASTM C1007 |
Installation of Load Bearing (Transverse and Axial) Steel Studs and Related Accessories |
| ASTM C1513 |
Steel Tapping Screws for Cold-Formed Steel Framing Connections |
| AWS D1.3/D1.3M |
Structural Welding Code — Sheet Steel |
| SSMA Product Technical Information |
Steel Stud Manufacturers Association — Member Designations, Section Properties, and Allowable Loads |
| IBC |
International Building Code, Chapter 22 (Steel) — current edition adopted by jurisdiction |
| ASCE 7 |
Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
| UL Fire Resistance Directory |
UL Fire-Resistance Rated Systems |
| GA-600 |
Fire Resistance and Sound Control Design Manual (Gypsum Association) |
NOTE AISI S240 and AISI S220 are the umbrella standards for structural and non-structural cold-formed steel framing respectively; both reference AISI S100 for member-level design provisions. (2.4.1)
NOTE AISI S400 is invoked in addition to S240 when the project is in Seismic Design Category D, E, or F, or when the CFSF participates in a designated seismic force-resisting system. (2.4.2)
NOTE The IBC adopts these AISI standards by reference in Chapter 22. (2.4.3)
3 Submittals
3.1 Action Submittals
3.1.1 The Contractor shall submit the following for review by the SER (for load-bearing CFSF) and the AOR (for non-load-bearing CFSF) prior to procurement and installation.
☑ Product data — structural studs and tracks (load-bearing and curtain-wall)
☐ Product data — non-structural studs and tracks (partition framing)
☐ Product data — joists, rafters, and built-up sections (where used)
☐ Product data — bridging, bracing, and clip connectors
☐ Product data — screws and powder-actuated fasteners
☐ Shop drawings for load-bearing and curtain-wall CFSF, sealed by licensed engineer
☐ Delegated design calculations (where design is delegated)
☐ Welding procedure specifications (AWS D1.3)
☐ Welder qualification records (AWS D1.3)
☐ Certified mill test reports (structural CFSF)
☐ Fire-resistance design number schedule (rated assemblies)
3.1.2 Installation shall not begin on structural cold-formed steel until the corresponding structural submittals have been reviewed and returned.
3.1.3 Non-structural partition framing may proceed under the AOR's standard submittal workflow.
3.1.4 Product data shall be submitted for each cold-formed steel framing member, accessory, fastener, and connector to be used on the project, including the manufacturer's published catalog or technical information sheet showing the SSMA designation (where applicable), base metal thickness in mils (and design thickness for structural members), web depth, flange width, return-lip dimension, minimum yield strength, coating designation, section properties (area, moment of inertia, section modulus), and where applicable, the manufacturer's allowable axial and transverse load tables.
3.1.5 Shop drawings shall be submitted for all load-bearing CFSF assemblies and for all CFSF used as wind-bearing curtain-wall framing.
3.1.6 Shop drawings shall be prepared by the cold-formed steel framing supplier's engineer (where panel design is delegated) or by the fabricator (where field-erected).
3.1.7 Shop drawings shall show every member designation and size, member spacing, top and bottom track conditions, bridging and bracing locations and types, opening framing (jambs, headers, sills, and cripples), connection details at the top and bottom tracks, connections to primary structure (clips, embeds, deflection tracks), screw types and patterns, and any field-welded connections including weld symbols, sizes, and applicable AWS D1.3 procedures.
3.1.8 Shop drawings shall be sealed by a licensed structural engineer in the state of the project where panel design or connection design is delegated to the supplier.
3.1.9 Delegated design calculations shall be submitted where any portion of the CFSF design is delegated to the supplier or fabricator's engineer, and shall demonstrate compliance with AISI S100, S240, and (where applicable) S400 for the gravity, wind, and seismic loads identified by the SER on the contract drawings.
NOTE The SER's review confirms that the delegated design meets the contract force and deflection requirements; the supplier's engineer retains responsibility for the detailed design. (3.1.10)
3.1.11 Welding procedure specifications (WPS) shall be submitted for any welded CFSF connections, in accordance with AWS D1.3/D1.3M.
NOTE AWS D1.3 specifically addresses welding of sheet steel 0.18 in. (4.6 mm) thick and less and has distinct procedures from AWS D1.1 (used for hot-rolled steel). (3.1.12)
3.1.13 Welder qualification records shall be submitted demonstrating qualification under AWS D1.3 for the processes, positions, and base metal thicknesses to be welded.
3.1.14 Mill test reports (CMTRs) shall be submitted for all structural CFSF members on request, confirming compliance with ASTM A1003/A1003M (or ASTM A653/A653M for the galvanized substrate where applicable), the specified minimum yield strength, and the specified metallic coating designation (G60 or G90).
3.1.15 For non-structural members furnished to ASTM C645, certification by the manufacturer that members meet the standard's minimum requirements is acceptable in place of full CMTRs.
3.2 Delegated Design
All CFSF members and connections fully detailed on contract drawings — no delegation
Curtain-wall (exterior non-load-bearing) stud size and bridging delegated to specialty engineer
Load-bearing wall panel design delegated to specialty engineer (forces shown on drawings)
All CFSF design delegated to specialty engineer (loads and deflection criteria shown on drawings)
NOTE Delegation of cold-formed steel design to a specialty engineer retained by the supplier is the prevailing practice in U.S. commercial construction for exterior curtain-wall studs, prefabricated load-bearing panel walls, and CFSF roof and floor trusses. (3.2.1)
3.2.2 The contract drawings shall provide the controlling loads (gravity reactions, wind pressures, seismic forces) and the controlling serviceability criteria (deflection limits, drift limits) so that the specialty engineer has all of the information needed to design the members and connections.
NOTE Delegation of design without a clear, complete statement of the design loads and deflection criteria leads to under- or over-designed framing and to disputes about scope. (3.2.3)
3.3 Closeout Submittals
3.3.1 At substantial completion, the Contractor shall provide the following closeout submittals:
- As-built shop drawings reflecting any field modifications or substitutions approved during construction
- Final inspection reports covering visual and welding inspections for structural CFSF
- Touch-up coating documentation
- Certificates of compliance from the supplier and installer attesting that the work was performed in accordance with the contract documents and applicable standards
☑ As-built shop drawings reflecting field modifications or substitutions
☑ Final inspection reports for visual and welding inspections (structural CFSF)
☑ Touch-up coating documentation
☑ Certificates of compliance from supplier and installer
4 Quality Assurance
4.1 Special Inspection
● Yes — per IBC Chapter 17 for cold-formed steel SFRS elements and welded connections
○ No — non-structural CFSF only; no special inspection required
4.1.1 Special inspection of cold-formed steel framing shall be performed in accordance with IBC Chapter 17 where structural CFSF is used.
4.1.2 The Statement of Special Inspections prepared by the SER shall list the required inspection tasks and frequencies (continuous or periodic).
4.1.3 At minimum, special inspection shall cover welding of structural cold-formed members per AWS D1.3, screw connections in designated shear walls and diaphragms, and members that are part of a seismic force-resisting system per AISI S400.
NOTE Non-structural CFSF (partition framing not carrying calculated loads beyond the finish) does not require special inspection. (4.1.4)
4.2 Installer Qualifications
● Minimum five years documented experience installing load-bearing CFSF on comparable projects
○ Manufacturer-approved or manufacturer-certified installer (for proprietary panel systems)
○ Minimum three years documented experience
NOTE Load-bearing cold-formed steel framing is a discipline distinct from non-structural drywall partition framing. (4.2.1)
4.2.2 The installer shall demonstrate experience installing structural CFSF on projects of comparable scope.
NOTE For non-structural partition framing, standard commercial drywall installer experience is acceptable; CFSF for partition framing is installed by the same trades that install gypsum board (see
Gypsum Board Assemblies).
(4.2.3) 4.3 Welder Qualifications
4.3.1 Welders performing structural cold-formed steel welding shall be qualified under AWS D1.3/D1.3M for the processes, positions, and sheet thicknesses to be welded.
4.3.2 Qualification shall be current and shall not have lapsed by more than six months without re-qualification.
NOTE AWS D1.3 qualification is separate from AWS D1.1 qualification used for hot-rolled steel; a welder qualified only under D1.1 is not automatically qualified for sheet steel welding. (4.3.3)
4.4 Pre-Installation Conference
4.4.1 Before installation of load-bearing CFSF or exterior curtain-wall CFSF begins, the Contractor shall hold a pre-installation conference with the SER (for load-bearing), the AOR, the framing installer, the gypsum board installer (where applicable), the cladding installer, and the manufacturer's technical representative where panel design is delegated.
4.4.2 The conference shall confirm the layout, deflection track conditions at top of wall, opening framing for doors and windows, bridging schedule, anchor and clip selections, and the coordination of cladding attachment details with the framing.
5 Environmental and Service Conditions
5.1 Interior vs. Exterior Service
Interior, dry — conditioned occupied space
Interior, intermittently humid — kitchens, laundries, swimming pool perimeter walls
Exterior, behind cladding — curtain-wall studs and load-bearing exterior walls
Exterior, exposed — direct weather exposure (canopies, soffits open at edges)
Coastal exterior — within 1 mile of saltwater
5.1.1 The service environment shall determine the minimum metallic coating designation required for the framing members.
NOTE Interior dry conditions are adequately protected by G40 coating (the minimum permitted by ASTM C645 for non-structural framing), but G60 is the prevailing minimum coating across both structural and non-structural CFSF in U.S. commercial practice. (5.1.2)
5.1.3 Exterior and intermittently humid conditions shall require G60 minimum and benefit from G90.
5.1.4 Coastal exterior installations shall require G90 minimum and often warrant a higher-performance coating system or stainless steel screws in lieu of standard galvanized fasteners.
NOTE Building science failures from corrosion of cold-formed steel framing inside wall assemblies are typically caused by sustained moisture infiltration into the cavity rather than by inadequate coating on the steel; specifying G90 for exterior assemblies is inexpensive insurance against the conditions that do occur. (5.1.5)
5.2 Storage and Handling
5.2.1 Cold-formed steel framing shall be delivered to the site in the manufacturer's original bundles, protected from weather and physical damage.
5.2.2 Materials shall be stored elevated above the ground on dunnage, covered to prevent water accumulation between members but ventilated to prevent condensation, and arranged to permit drainage.
NOTE Wet bundles of galvanized framing develop white rust (zinc carbonate bloom) within hours when air circulation is restricted; white rust is cosmetic on light deposits but compromises the metallic coating where heavy. (5.2.3)
5.2.4 Damaged or corroded members shall not be installed without the AOR's or SER's written acceptance.
5.2.5 Members with section loss from corrosion shall be rejected.
6 Materials
ASTM A1003/A1003M, ST33H (Fy = 33 ksi)
ASTM A1003/A1003M, ST50H (Fy = 50 ksi)
ASTM A1003/A1003M, ST55H (Fy = 55 ksi)
NOTE ASTM A1003/A1003M is the consolidated material standard for cold-formed framing members and covers galvanized sheet steel produced for cold-forming. (6.1.1)
NOTE Structural members under AISI S240 are designated with the suffix "ST" (structural) and a yield strength: ST33H (33 ksi yield, the older minimum still used for some light-gauge structural members), ST50H (50 ksi yield, the current standard for the vast majority of structural CFSF), and ST55H (55 ksi yield, used in selected proprietary heavy-gauge members). (6.1.2)
NOTE The "H" denotes that the steel is suitable for hot-dip metallic coating per ASTM A653/A653M. (6.1.3)
NOTE ST50H at 50 ksi yield is the SSMA reference standard for structural studs at 33 mil through 97 mil designations and is the appropriate default for nearly all U.S. commercial work. (6.1.4)
6.1.5 SSMA Designation System
S — Structural stud (C-shape with return lips)
T — Track (U-shape with no return lips)
U — Cold-rolled channel (used for bridging and bracing)
F — Furring channel (hat-section)
L — Angle or clip
Joist (deeper C-section)
NOTE The Steel Stud Manufacturers Association (SSMA) designation system identifies a cold-formed member with a four-part code that specifies web depth, flange width, member type, and base metal thickness. (6.1.5.1)
NOTE For example, the designation 362S162-43 indicates: 362 = 3.625 in. web depth (in hundredths of an inch), S = structural C-stud (with return lips), 162 = 1.625 in. flange width, and 43 = 43-mil (0.0451 in.) minimum base metal thickness. (6.1.5.2)
NOTE The full SSMA system covers studs (S), tracks (T), U-channels (U), hat furring (F), and L-section angles. (6.1.5.3)
2.5 in. (250)
3.5 in. (350)
3.625 in. (362)
4 in. (400)
5.5 in. (550)
6 in. (600)
8 in. (800)
10 in. (1000)
12 in. (1200)
Per drawings (deferred by default)
1.250 in. (125)
1.375 in. (137)
1.625 in. (162) — standard SSMA flange
2.000 in. (200) — extra-wide flange for higher buckling capacity
2.500 in. (250) — joist flange
NOTE The 1-5/8 in. flange (162) is the SSMA standard structural stud flange and is suitable for the great majority of stud applications. (6.1.5.4)
NOTE A wider 2 in. flange (200) is available in heavier-gauge structural studs and is used where additional flange width increases local buckling capacity at high axial loads. (6.1.5.5)
NOTE Deeper joist members typically have 2-1/2 in. flanges for compatibility with floor deck and screw spacing. (6.1.5.6)
6.1.5.7 Members shall be specified by SSMA designation rather than by gauge alone to ensure unambiguous procurement, which is the dominant U.S. convention for structural CFSF.
33 mil (20 gauge structural, 0.0346 in.)
43 mil (18 gauge, 0.0451 in.)
54 mil (16 gauge, 0.0566 in.)
68 mil (14 gauge, 0.0713 in.)
97 mil (12 gauge, 0.1017 in.)
118 mil (10 gauge, 0.1242 in.)
Per drawings (deferred by default)
NOTE Cold-formed steel framing is designated by the minimum base metal thickness in mils (thousandths of an inch), not by the older gauge system. (6.1.6.1)
NOTE The mil designation system was adopted by the industry because gauge numbers are not standardized between manufacturers and because the design thickness used in AISI S100 calculations is the minimum base metal thickness, not the nominal coating-inclusive thickness. (6.1.6.2)
NOTE The conversion between gauge and mil is provided in the manufacturer literature; for reference, 43 mil corresponds to nominal 18 gauge structural and 33 mil to nominal 20 gauge structural. (6.1.6.3)
NOTE The "structural" qualifier on 20 gauge is important: ASTM C645 (non-structural) 20 gauge is permitted to be as thin as 18 mil, whereas ASTM C955 (structural) 20 gauge is 33 mil minimum. (6.1.6.4)
NOTE Specifying "20 gauge" without identifying structural vs. non-structural creates ambiguity that has produced bidding and procurement errors; the mil designation is unambiguous. (6.1.6.5)
G40 — minimum permitted, interior dry only
G60 — standard for U.S. commercial CFSF (interior and behind cladding)
G90 — exterior assemblies, humid interiors, and within 1 mile of saltwater
6.1.7.2 AISI S240 shall require a minimum of G60 for structural cold-formed steel in most applications; G40 is permitted only for interior, dry, conditioned applications.
6.1.7.3 G90 shall be the default for exterior wall assemblies, intermittently humid interior conditions, and any installation within one mile of saltwater coastline.
6.1.7.4 Where aluminum-zinc alloy coatings (AZ50, AZ55) or zinc-aluminum-magnesium coatings are specified as alternates, the specification shall identify the coating standard and minimum coating weight to ensure procurement equivalence.
ASTM C645 minimum thickness (15 mil / 25 gauge nominal — most interior partitions)
ASTM C645 18 mil / 22 gauge nominal (taller partitions, higher rated assemblies)
ASTM C645 27 mil / 20 gauge nominal (taller or specialty partitions)
ASTM C645 30 mil / 20 gauge equivalent (heavy non-structural)
NOTE ASTM C645 governs non-structural steel framing members intended only to support gypsum board and plaster bases. (6.2.1)
NOTE The minimum permitted base metal thickness under ASTM C645 is 15 mil (often described as 25 gauge nominal), which is adequate for partition heights up to approximately 10 ft at 16 in. on center supporting one layer of 5/8 in. gypsum board on each face. (6.2.2)
NOTE Taller partitions, partitions with two layers of board per face, and partitions in higher fire-resistance-rated assemblies require thicker base metal — typically 18 mil, 27 mil, or 30 mil — selected per the partition height tables published by manufacturers and by GA-600 design data. (6.2.3)
1-5/8 in. (158)
2-1/2 in. (250)
3-1/2 in. (350)
3-5/8 in. (362)
4 in. (400)
6 in. (600)
Per drawings — architectural partition type schedule (deferred by default)
12 in. on center
16 in. on center
24 in. on center
NOTE Stud spacing of 16 in. on center is the U.S. standard for non-structural partition framing supporting one layer of 5/8 in. gypsum board on each face. 24 in. on center is permitted for many partition heights with 5/8 in. board but reduces partition stiffness and is more sensitive to point loads (wall-hung items, door operating shocks, partition rattle). 12 in. on center is used where partition height, deflection criteria, or surface impact resistance require closer spacing. (6.2.4)
6.2.5 The specifier shall verify that the selected gauge meets the partition height and deflection criteria for each partition type indicated on the architectural drawings.
6.3 Tracks and Runners
Standard track — same gauge as connected studs
Deflection track (slip track) — vertical deflection capacity at top of wall
Drift track — combined vertical deflection and seismic horizontal drift
NOTE Track sections (designated "T" in the SSMA system) are U-shaped channels that receive the ends of studs at the top and bottom of a wall. (6.3.1)
NOTE Standard tracks match the connected studs in base metal thickness and have the same flange dimension as the stud web depth. (6.3.2)
NOTE Deflection tracks (slip tracks) provide vertical relief at the top of non-load-bearing walls so that primary structure deflection from live, snow, or seismic loads does not transfer into the partition wall and crack finishes — the stud slides freely within the deflection track up to the rated travel. (6.3.3)
1/2 in. vertical deflection
3/4 in. vertical deflection
1 in. vertical deflection
1-1/2 in. vertical deflection
Per drawings — structural drawings (deferred by default)
6.3.4 Deflection tracks shall be provided at the top of interior partitions and curtain-wall studs that extend to the underside of structure above, and the rated deflection capacity shall meet or exceed the calculated deflection of the structure above.
6.3.5 Drift tracks, which combine vertical deflection capacity with seismic horizontal drift accommodation, shall be used in seismic design categories C through F where in-plane drift of the primary frame would otherwise damage interior partition framing.
6.3.6 The deflection track shall be sized to accommodate at least the calculated total deflection of the primary structure above the wall, including the elastic deflection under live loads and any inelastic seismic drift where applicable.
NOTE Specifying an undersized deflection track is one of the most common interior partition failures, generating cracked drywall and broken corner bead at occupancy. (6.3.7)
6.4 Joists, Rafters, and Built-Up Sections
NOTE Cold-formed steel joists and rafters are deeper C-section members (typically 6 in. to 12 in. web depth) used for floor and roof framing where light-gauge structural framing is selected over open-web steel joists or hot-rolled wide flange beams. (6.4.1)
● Not applicable — floor and roof framing by other materials
○ CFSF joists per structural drawings and supplier load tables
○ Proprietary CFSF truss system, supplier-designed and supplied
6.4.2 Joist member sizes, spacing, lateral bracing, and bearing details shall be designed per AISI S100 and S240.
6.4.3 Joists shall be selected from manufacturer load tables that correspond to the actual span, spacing, and loading shown on the structural drawings.
6.4.4 Built-up sections — pairs or triples of studs connected back-to-back or as boxed sections — shall be used for jamb studs at large openings, header members, and column-like members where a single C-section would be inadequate.
6.5 Bridging and Bracing
Cold-rolled channel through punched stud knockouts, with clip angles welded or screwed
Proprietary bridging bar through stud knockouts with proprietary clips
Steel strap on both faces, screwed to each stud, with periodic solid blocking
Sheathing-braced design (per AISI S240 sheathing-braced provisions)
NOTE Bridging restrains structural studs against rotation and weak-axis buckling at intermediate points along the stud length. (6.5.1)
NOTE Each stud manufactured for structural CFSF has factory-punched knockout slots in the web at standard intervals (typically 12 in. or 24 in. on center vertically) sized to receive a 3/4 in. or 1-1/2 in. cold-rolled channel (CRC) used as bridging. (6.5.2)
NOTE The CRC passes through every stud in the wall and is fixed to each stud with a clip angle screwed or welded to the stud flange. (6.5.3)
NOTE Proprietary clip-and-bar systems achieve the same function with snap-in or screw-in connectors and are increasingly common because they reduce labor at each connection. (6.5.4)
NOTE Strap bracing on both faces (with periodic solid blocking) is used where stud knockouts cannot be aligned or where sheathing is not relied upon for diaphragm action. (6.5.5)
4 ft on center (heavy or tall studs)
5 ft on center
6 ft on center
8 ft on center
Per drawings — structural drawings (deferred by default)
6.5.6 The maximum vertical spacing of bridging rows shall be governed by AISI S100 weak-axis buckling provisions and by AISI S240 detailing requirements; typical commercial values are 4 ft to 8 ft on center.
6.5.7 The specialty engineer responsible for the wall design shall determine the actual spacing, which shall be shown on the shop drawings and confirmed against the manufacturer's published load tables.
6.6 Connectors and Clip Angles
Manufacturer-standard L-clip angles (matched to stud gauge)
Proprietary engineered slide clips (vertical-only movement)
Proprietary engineered drift clips (vertical plus in-plane lateral movement)
Bypass slip connectors (curtain-wall bypass framing)
NOTE Engineered slide clips and drift clips provide controlled freedom of movement at the top of curtain-wall studs to accommodate primary structure deflection and seismic drift without transferring those movements into the framing or cladding. (6.6.1)
6.6.2 Clip connectors at the connection of CFSF to primary structure or to other CFSF members shall be selected to transfer the calculated forces without imposing rotational restraint where rotational freedom is required.
6.6.3 Manufacturer's published load tables shall be the basis for clip selection; clip type, size, and screw or weld pattern shall be shown on the shop drawings.
6.7 Fasteners
6.7.1 Self-Drilling Tapping Screws
ASTM C1513 #8 self-drilling tapping screws — non-structural partition framing
ASTM C1513 #10 self-drilling tapping screws — structural CFSF, standard connections
ASTM C1513 #12 self-drilling tapping screws — structural CFSF, heavy gauge connections
ASTM C1513 #14 self-drilling tapping screws — heaviest gauge structural connections
NOTE #8 screws are standard for non-structural partition framing through 33 mil and thinner members. (6.7.1.1)
NOTE #10 screws are the standard for structural CFSF through approximately 54 mil; #12 and #14 screws are used in heavier-gauge connections. (6.7.1.2)
○ Zinc-plated (mechanical or electroplated) — interior dry only
● Hot-dip galvanized — interior intermittently humid, behind cladding
○ Climaseal, Stalgard, or equivalent coating — exterior assemblies and coastal conditions
○ Type 410 stainless — most aggressive corrosion environments
6.7.1.3 Self-drilling tapping screws used for cold-formed steel framing connections shall comply with ASTM C1513.
6.7.1.4 Screw size shall be selected based on the combined thickness of the connected steel and the calculated screw shear and pullout demand.
6.7.1.5 Screw spacing, edge distance, and minimum end distance shall be shown on the shop drawings and shall comply with AISI S100 Section E4 connection provisions and the manufacturer's published values.
6.7.1.6 Screw coating shall match or exceed the corrosion environment of the assembly.
NOTE The zinc plating on standard screws sold for interior drywall work is inadequate for screws in exterior wall assemblies and within the building envelope of exterior walls; field reports of corroded screws in wall cavities are typically of standard zinc-plated screws used where a corrosion-resistant coating was required. (6.7.1.7)
6.7.2 Powder-Actuated Fasteners
● Permitted for non-structural track to concrete or steel substrates
○ Permitted for structural track per supplier engineer's design and tested values
○ Not permitted — anchors or screws only
NOTE Powder-actuated fasteners (PAFs) are commonly used to anchor bottom and top tracks to concrete slabs and to hot-rolled steel beams; they are appropriate and code-compliant for non-structural partition tracks to either substrate. (6.7.2.1)
6.7.2.2 Use of PAFs in load-bearing or shear-wall track connections shall be limited to fasteners with published, tested capacities and shall be designed by the SER or the delegated specialty engineer.
6.7.2.3 PAFs shall not be installed within minimum edge distances of concrete or near concrete reinforcement.
6.7.2.4 PAFs shall be inspected after installation for proper embedment.
6.7.3 Welded Connections
● Not used — connections are all screws or PAFs
○ Used in shop only, per AWS D1.3 with qualified WPS and welders
○ Used in shop and field, per AWS D1.3 with qualified WPS and welders
NOTE Field welding of cold-formed steel framing is less common than screw or PAF connections because of the labor cost, the burn-through risk, and the damage to the galvanized coating around the weld. (6.7.3.1)
6.7.3.2 Welded connections in cold-formed sheet steel shall conform to AWS D1.3/D1.3M (Structural Welding Code — Sheet Steel), which is distinct from AWS D1.1 (used for hot-rolled steel).
6.7.3.3 The minimum sheet thickness at which welding is reliably acceptable for structural connections is governed by AWS D1.3 and is approximately 0.025 in. (25 mil); welds on thinner sheet are unreliable because of burn-through and rapid cooling.
6.7.3.4 Where field welding is used, the damaged coating shall be repaired with a zinc-rich cold galvanizing compound applied within 24 hours of welding.
7 Installation
7.1 Coordination With Other Trades
7.1.2 Penetrations through studs shall use the manufacturer's factory-punched knockouts wherever possible.
7.1.3 Field-cut openings shall be made by mechanical means (hole saw or rotary cutter) and shall not exceed the dimensions or location permitted by the supplier's published values.
7.1.4 Torch cutting of cold-formed steel framing in the field is prohibited; the heat distorts the section, destroys the metallic coating, and produces uncontrolled openings.
7.2 Layout
7.2.1 Layout of partition and load-bearing walls shall be performed from the project control points established by the General Contractor.
7.2.2 The framing layout shall match the partition plan dimensions, and stud spacing shall be measured from the same end of the wall in each course of framing to maintain alignment for gypsum board joints.
7.2.3 At door and window openings, jamb studs shall be located so that the rough opening matches the requirements of the specified door or window per Doors Frames And Hardware. 7.2.4 Floor and ceiling tracks shall be set first, accurately aligned with the wall layout, and fastened to the structural substrate before studs are installed.
7.3 Track Anchorage to Substrate
Powder-actuated fasteners at maximum 24 in. on center (non-structural)
Expansion anchors at maximum 24 in. on center
Powder-actuated fasteners with tested capacity, spacing per design (structural)
Cast-in anchor bolts per structural drawings (structural)
7.3.1 Bottom track fastener spacing shall be the lesser of the manufacturer's recommendation, 24 in. on center for non-structural partitions, and the structural design spacing for load-bearing walls.
7.3.2 Fasteners shall be installed within 2 in. of the end of each track section and at each end of openings.
7.3.3 Specifying PAFs for structural loads without manufacturer-tested values is not acceptable, because the actual capacity of PAFs in concrete depends strongly on the concrete strength and the presence of nearby reinforcement.
7.4 Stud Installation
1/8 in. in 10 ft (standard)
1/16 in. in 10 ft (tight tolerance — architecturally exposed)
7.4.1 Studs shall be plumb within 1/8 in. in 10 ft and shall fit snugly within the top and bottom tracks.
7.4.2 Studs shall be screwed or welded to both top and bottom tracks for load-bearing walls; for non-load-bearing partitions with deflection track at the top, studs shall be screwed to the bottom track only and shall be free to slide within the deflection track at the top.
7.4.3 Studs shall not be cut short to accommodate framing errors; short studs shall be replaced with full-length members.
7.4.4 Studs that are skewed, kinked, or bent shall be rejected and replaced before gypsum board installation begins, because the resulting wall surface will telegraph the distortion through the finished board.
7.5 Opening Framing
NOTE Door and window openings in CFSF walls require additional framing: jamb studs (often built-up from two or more studs box-connected back-to-back), a header member spanning the opening, a sill member at window openings, and cripple studs at the header and sill to maintain stud spacing pattern. (7.5.1)
Single stud (small openings up to 36 in., light interior doors)
Two studs box-connected (standard interior commercial doors)
Two studs back-to-back (heavy doors, frame-supporting jambs)
Built-up section per shop drawings (large openings, structural jambs)
7.5.2 Opening framing shall be detailed on the shop drawings and shall be sized to carry the loads transferred from the interrupted studs above.
7.5.4 Jamb stud gauge shall be at least equal to the adjacent field stud gauge and shall be increased where required by the opening width and the door weight.
7.6 Bridging Installation
7.6.1 Bridging shall be installed at the spacing and locations shown on the shop drawings before any sheathing or gypsum board is applied.
7.6.2 CRC bridging shall be passed through each stud knockout in a continuous line and shall be fastened to each stud with a clip angle on at least one side of the CRC; AISI S240 requires both stiffness and strength at the bridging-to-stud connection sufficient to restrain the stud against rotation.
7.6.3 Bridging at the ends of walls and at openings shall be tied back to a stable element (a solid blocked stud at a wall end, a jamb stud at an opening) to prevent the bridging from sagging or pulling out at the termination.
7.7 Wall Bracing and Diaphragm
Sheathing-braced design — gypsum board or wood sheathing provides shear capacity
Strap-braced X-bracing in designated bracing bays
Cold-formed steel shear walls per AISI S240
Walls are non-load-bearing — lateral resistance not within scope
7.7.1 Where the CFSF wall serves as part of the lateral force-resisting system, the design basis for that system shall be shown clearly on the structural drawings.
7.7.2 Sheathing-braced walls rely on the sheathing material (gypsum board, oriented strand board, or steel sheet) and its fastener pattern to resist racking; the design and detailing per AISI S240 are sensitive to fastener spacing and edge distance, and field substitution of fastener pattern is not permitted.
7.7.3 Strap X-bracing in designated bays uses tension straps fastened diagonally across stud faces; strap material, thickness, attachment screw pattern, and termination details shall be per the shop drawings.
7.7.4 Cold-formed steel shear walls under AISI S240 or AISI S400 (seismic) require strict adherence to the design provisions and special inspection during construction.
7.8 Welded Connection Installation
7.8.1 Where welded connections are used, the welder shall verify that the WPS for the actual sheet thickness is available at the workstation, that the welding equipment is set to the parameters of the WPS, and that the base metal is clean and dry.
7.8.2 Burn-through, blowout, and inadequate fusion are the most common welding defects in sheet steel; defects shall be repaired only by qualified welders and shall be re-inspected after repair.
7.8.3 The galvanized coating shall be removed from the immediate weld area by mechanical means before welding to avoid zinc contamination of the weld pool, and the coating shall be restored with a zinc-rich cold galvanizing compound after welding is complete.
7.9 Penetrations and Notching
7.9.1 Penetrations through stud webs for piping, conduit, and cabling shall use the manufacturer's factory-punched knockouts where possible.
7.9.2 Field-cut penetrations shall not exceed the dimensions, spacing, or location restrictions specified by the supplier (AISI S100 and S240 provide default rules; supplier-published values may be more restrictive for proprietary sections).
7.9.3 Notching of stud flanges is prohibited for structural members; notched flanges drastically reduce moment capacity at the notch and shall not be used as a substitute for proper opening framing.
7.9.4 Field-cut penetrations in tracks shall not exceed the manufacturer's published values; track penetrations near anchor locations shall be avoided.
7.10 Coordination With Cladding
7.10.1 Curtain-wall studs that support exterior cladding shall be installed with the deflection track or slide clip at the top of the wall before the cladding is installed, and the deflection clearance shall be maintained throughout the cladding installation.
7.10.2 The cladding installer and the framing installer shall confirm the deflection track condition at the pre-installation conference.
NOTE Cladding anchored solidly across the deflection track defeats the deflection accommodation function and is a frequent cause of cracked cladding and broken sealants at upper occupied floors of mid-rise buildings. (7.10.3)
8 Fire-Resistance-Rated Assemblies
NOTE Cold-formed steel framing is a permitted substrate for many UL-classified and GA-600 fire-resistance-rated wall and floor assemblies. (8.1)
NOTE The fire-resistance rating depends on the precise assembly — stud gauge, stud spacing, board type and thickness, fastener pattern, cavity insulation, and perimeter conditions — and a change to any component invalidates the listing. (8.2)
Provided in architectural partition type schedule
Provided in structural drawings
Submitted by Contractor for AOR review
8.3 The Contractor shall identify each rated assembly by its UL design number or GA-600 reference and shall install the assembly per that design.
8.4 CFSF stud gauge for rated assemblies shall be governed by the specific UL or GA-600 design rather than by the load on the wall; a non-load-bearing partition in a 2-hour assembly may require a heavier gauge than the same partition would require structurally, because the listed design was tested with that gauge.
8.5 Substitution of a thinner gauge than the listing requires shall not be permitted without an engineering judgment letter issued by a qualified party (UL, GA, or a licensed engineer with fire-resistance expertise) and approved in writing by the AOR.
8.6 Firestopping at penetrations through rated CFSF assemblies shall be installed per Firestopping and shall use UL-classified firestop systems for the specific assembly and penetration condition. 9 Testing and Inspection
9.1 Visual Inspection
9.1.1 All cold-formed steel framing shall be visually inspected by the installer's foreman before gypsum board, sheathing, or cladding is applied.
9.1.2 Visual inspection shall verify that members are the size and gauge shown on the shop drawings; that framing layout matches the contract drawings; that studs are plumb within tolerance and seated in tracks; that bridging is installed at the specified spacing with clip angles in place; that openings are framed with the specified jamb and header members; that fasteners are installed at the specified spacing, with no missing fasteners and no stripped or backed-out screws; and that the galvanized coating is intact, with any field damage repaired with zinc-rich cold galvanizing compound.
9.2 Special Inspection — Welded Connections
● Visual inspection only (standard for CFSF welds)
○ Visual inspection plus magnetic particle testing on demand-critical welds
9.2.1 Where welded connections are used in structural CFSF, special inspection per AWS D1.3 shall be performed by a qualified inspector.
9.2.2 Inspection shall verify weld size, length, location, fusion, and freedom from cracks, burn-through, and undercut.
9.2.3 Repairs to defective welds shall be re-inspected after repair.
NOTE Visual inspection per AWS D1.3 is the standard for cold-formed sheet steel welds; volumetric NDT (UT, RT) is not generally meaningful on sheet steel because of the limited section thickness, and MT may be appropriate for designated demand-critical welds in seismic CFSF systems per AISI S400. (9.2.4)
9.3 Special Inspection — Screw Connections in Designated Shear Walls
9.3.1 Where the CFSF wall is part of a designated shear wall under AISI S240 or AISI S400, the screw pattern at panel edges and at field studs shall be inspected before the sheathing is concealed.
9.3.2 Inspection shall verify that screws are the type and size shown on the shop drawings, that spacing matches the listed shear wall design, that edge distance is maintained, and that screws are properly seated (heads flush, not over-driven, not under-driven).
9.3.3 The shear capacity of cold-formed steel shear walls is highly sensitive to fastener pattern; field substitution is not permitted.
10 Delivery, Storage, and Handling
☑ Store on timber dunnage elevated above ground surface
☐ Arrange bundles to permit drainage and prevent water accumulation
☐ Cover to exclude weather but permit air circulation (no sealed plastic)
☐ Separate by member designation and gauge to prevent installation errors
☐ Inspect for transit damage on arrival; reject members with section damage
10.1 Cold-formed steel framing shall be delivered to the project site in the manufacturer's standard bundles, with each bundle clearly marked with the member designation, gauge, coating, and quantity.
10.2 Members shall be unloaded with care to prevent kinking, twisting, or denting.
10.3 Members shall be stored on dunnage above the ground surface, arranged to drain water away, and covered loosely with breathable material that excludes weather but permits air circulation.
10.4 If material arrives wrapped in plastic, the wrap shall be loosened or removed promptly, because tightly sealed coverings that trap moisture against bundled members are a frequent cause of white rust formation on galvanized framing within hours of arrival.
10.5 Members showing white rust shall be inspected before installation; light white rust is cosmetic and may be wiped clean, but heavy white rust indicates loss of zinc coating and the affected members shall be rejected.
10.6 Members with kinks, twists, dents in the web that exceed 1/8 in., or coating damage exceeding the limits of touch-up shall not be installed without the SER's or AOR's written acceptance.
11 Warranty
1 year from substantial completion
2 years from substantial completion
11.1 The supplier shall warrant the cold-formed steel framing products against defects in material and manufacturing, including incorrect gauge, incorrect coating, and section properties not matching published values.
11.2 The installer shall warrant the installation against defects in workmanship, including incorrect member layout, missing or improperly installed bridging, missing or under-driven fasteners, plumbness deviations, and damage to coatings caused by installation operations.
11.3 The warranty does not cover damage caused by other trades, overloading beyond the design basis, modifications by others after completion, or corrosion attributable to water infiltration through the building envelope that is unrelated to the framing installation.
11.4 Where delegated design is used, the specialty engineer's professional liability for the design of the framing system extends per the engineer's professional services agreement and is not limited by the construction warranty period.