How do steel plate shear walls (SPSW) work?

Steel plate shear walls (SPSW) per AISC 341-22 Section F5 consist of thin steel infill plates bounded by vertical boundary elements (VBE, columns) and horizontal boundary elements (HBE, beams). Under lateral load, the thin plate buckles in shear and develops a diagonal tension field — conceptually similar to a Pratt truss where the plate acts as diagonal tension members and the boundary elements act as chords. The nominal shear strength Vn = 0.42 × Fy × tw × Lcf × sin(2α) where Fy is the plate yield strength (typically A36, 36 ksi), tw is plate thickness, Lcf is the clear span between VBE flanges, and α is the tension field angle from vertical (approximately 40-45° for typical panel aspect ratios). Example: a 20 ft bay SPSW with 3/16" A36 plate at a 3-story building with story shear Vu = 480 kips and α = 42°. φVn = 0.90 × 0.42 × 36 × 0.1875 × 228 × sin(84°) = 0.90 × 0.42 × 36 × 0.1875 × 228 × 0.995 = 0.90 × 516 = 464 kips. Since 464 kips < 480 kips, increase plate to 1/4": φVn = 0.90 × 0.42 × 36 × 0.25 × 228 × 0.995 = 0.90 × 688 = 619 kips — acceptable. SPSW system factors per ASCE 7 Table 12.2-1: R = 7, Ω₀ = 2, Cd = 5½. The infill plate must be A36 (not higher strength) to ensure yielding occurs before boundary element failure per capacity design. SPSWs provide 2-3× the stiffness of equivalent braced frames for the same bay width, making them very efficient in high-seismic applications.

How are SPSW boundary elements designed?

SPSW boundary element design follows capacity design principles per AISC 341-22 Section F5. The boundary columns (VBE) and beams (HBE) must resist forces corresponding to the fully yielded and strain-hardened infill plate: (1) VBE axial force Pu_VBE = Σ(0.5 × Ry × Fy × tw × H × sin²α) from each adjacent panel plus gravity loads, where Ry = 1.3 for A36 plate per AISC 341 Table A3.1. (2) VBE must also satisfy compactness requirements (λ ≤ λps per AISC 341 Table D1.1) to sustain plastic rotations at the panel corners. (3) HBE must resist the vertical component of the tension field: Mu_HBE = (1/8) × Ry × Fy × tw × Lcf² × ω where ω accounts for the vertical component of the tension field. (4) The VBE moment demand from tension field anchorage: Mu_VBE = (1/12) × Ry × Fy × tw × H² × cos²α, added to axial-flexural interaction. (5) VBE splices must develop the full expected strength, not just the demand, per AISC 341 Section D2.5. (6) HBE-to-VBE connections are typically full-penetration welds developing the HBE flange forces. The infill plate is fillet-welded to the fish plates (connection plates welded to the VBE and HBE). Fish plate thickness should be at least 1.5 × tw to ensure the plate yields before the connection. Minimum plate thickness for handling and welding: 1/4" for plates up to 10 ft panel height, 3/8" for 10-15 ft.

What are the drift limits for steel framed wall systems?

Drift limits per ASCE 7-22 Table 12.12-1 and IBC Table 1604.3 apply to steel framed wall systems: (1) Seismic drift: story drift Δ ≤ 0.020hsx for Risk Category I-II (SPSW, SCBF, SMF), 0.015hsx for Risk Category III, and 0.010hsx for Risk Category IV — where hsx is the story height below the level under consideration. For a 13 ft story, allowable story drift = 0.020 × 13 ft = 3.12" for standard occupancies. The design story drift Δ = Cd × δe / Ie where Cd = 5½ for SPSW systems and δe is the elastic displacement from reduced seismic forces. (2) Wind drift: typically H/400 for buildings over 10 stories (common industry practice, not a code mandate) to control cladding damage, and H/500 for hotels and residential to control partition cracking. (3) SPSW stiffness: an SPSW panel with 1/4" A36 plate, 20 ft bay, 13 ft story has initial stiffness K_initial ≈ 2,000-3,000 kips/inch before plate buckling. After buckling, the post-buckled stiffness is approximately 10-15% of the initial — the tension field action provides reliable post-buckling capacity with 0.02+ rad drift capacity. (4) P-delta effects: ASCE 7-22 Section 12.8.7 requires that the stability coefficient θ = Px × Δ × Ie / (Vx × hsx × Cd) ≤ 0.10 (or θmax = 0.5/(β × Cd) ≤ 0.25). If θ > 0.10, member forces and drifts must be amplified by 1/(1 − θ).

How do cold-formed steel (CFS) stud walls differ from structural steel walls?

Cold-formed steel (CFS) stud walls per AISI S213 and AISI S100 differ fundamentally from hot-rolled structural steel walls: (1) Material — CFS uses thin sheet steel (33-97 ksi yield, typically Grade 50) formed at room temperature into C-shape studs and U-shape tracks, typically 0.018" to 0.071" thick (25-14 gauge). (2) Load path — CFS studs are primarily vertical load-bearing (axial) or non-structural partition walls. Lateral resistance is typically provided by steel strap X-bracing or sheathing (plywood, OSB, gypsum, or steel sheet). (3) Design code — AISI S100 governs member design with provisions for local buckling, distortional buckling, and global buckling. The effective width method accounts for post-buckling strength in thin elements. (4) Typical stud sizes: 2-1/2", 3-5/8", 4", 6", 8", 10", 12" web depths × 1-3/8" or 1-5/8" flanges. Stud spacing 12", 16", or 24" o.c. (5) Load capacity — a 6" × 1-5/8" × 54 mil (16 gauge, Grade 50) stud at 8 ft height carries approximately 3-8 kips axial depending on sheathing bracing. (6) CFS is NOT used for lateral force-resisting systems in mid-to-high-rise buildings — that role goes to structural steel SPSW, SCBF, or SMF. CFS lateral systems are limited to low-rise (≤ 3 stories for bearing wall systems in SDC D per ASCE 7 Table 12.2-1). The key advantage: CFS walls are 40-60% lighter than equivalent concrete/masonry walls and can be erected without heavy equipment.

What are the practical considerations for SPSW construction?

Practical SPSW construction considerations: (1) Plate delivery and handling — SPSW infill plates are typically 3/16" to 3/8" thick, 8-15 ft tall, and 15-25 ft wide, weighing 500-2,500 lb each. They are shipped flat and must be handled without excessive bending that could kink the plate. (2) Welding sequence — fish plates are shop-welded to the VBE and HBE. The infill plate is field-welded to the fish plates using fillet welds. Welding should proceed from the center outward to minimize distortion. (3) Plate camber — due to the thin plate dimensions, SPSW plates may exhibit slight out-of-plane camber from rolling, handling, and welding. AISC 341 permits up to H/100 out-of-plane deviation without remediation (approximately 1.5" for a 13 ft panel). (4) Fish plate detailing — fish plates provide a backing bar for the infill plate fillet weld. Minimum fish plate thickness = 3/8" or 1.5 times the infill plate thickness. Fish plates are continuously fillet-welded to the boundary elements. (5) Openings — SPSW panels can accommodate small openings (up to 15% of panel area) for doors, windows, or MEP penetrations by adding local boundary elements around the opening. Larger openings require a redesign to transfer the tension field around the opening. (6) Cost — SPSW construction is competitive with SCBF for buildings above 12-15 stories where the stiffness advantage reduces drift-control member sizes. For low-rise, braced frames are typically more economical. (7) Fire protection — the infill plate must be fireproofed similarly to columns; the thin plate requires stiffened SFRM attachment or intumescent coating.

Steel Framed Walls — Steel Plate Shear Walls and CFS Stud Walls

Q: How are SPSW boundary elements designed?

SPSW boundary element design follows capacity design principles per AISC 341-22 Section F5. The boundary columns (VBE) and beams (HBE) must resist forces corresponding to the fully yielded and strain-hardened infill plate: (1) VBE axial force Pu_VBE = Σ(0.5 × Ry × Fy × tw × H × sin²α) from each adjacent panel plus gravity loads, where Ry = 1.3 for A36 plate per AISC 341 Table A3.1. (2) VBE must also satisfy compactness requirements (λ ≤ λps per AISC 341 Table D1.1) to sustain plastic rotations at the panel corners. (3) HBE must resist the vertical component of the tension field: Mu_HBE = (1/8) × Ry × Fy × tw × Lcf² × ω where ω accounts for the vertical component of the tension field. (4) The VBE moment demand from tension field anchorage: Mu_VBE = (1/12) × Ry × Fy × tw × H² × cos²α, added to axial-flexural interaction. (5) VBE splices must develop the full expected strength, not just the demand, per AISC 341 Section D2.5. (6) HBE-to-VBE connections are typically full-penetration welds developing the HBE flange forces. The infill plate is fillet-welded to the fish plates (connection plates welded to the VBE and HBE). Fish plate thickness should be at least 1.5 × tw to ensure the plate yields before the connection. Minimum plate thickness for handling and welding: 1/4" for plates up to 10 ft panel height, 3/8" for 10-15 ft.

Q: What are the drift limits for steel framed wall systems?

Drift limits per ASCE 7-22 Table 12.12-1 and IBC Table 1604.3 apply to steel framed wall systems: (1) Seismic drift: story drift Δ ≤ 0.020hsx for Risk Category I-II (SPSW, SCBF, SMF), 0.015hsx for Risk Category III, and 0.010hsx for Risk Category IV — where hsx is the story height below the level under consideration. For a 13 ft story, allowable story drift = 0.020 × 13 ft = 3.12" for standard occupancies. The design story drift Δ = Cd × δe / Ie where Cd = 5½ for SPSW systems and δe is the elastic displacement from reduced seismic forces. (2) Wind drift: typically H/400 for buildings over 10 stories (common industry practice, not a code mandate) to control cladding damage, and H/500 for hotels and residential to control partition cracking. (3) SPSW stiffness: an SPSW panel with 1/4" A36 plate, 20 ft bay, 13 ft story has initial stiffness K_initial ≈ 2,000-3,000 kips/inch before plate buckling. After buckling, the post-buckled stiffness is approximately 10-15% of the initial — the tension field action provides reliable post-buckling capacity with 0.02+ rad drift capacity. (4) P-delta effects: ASCE 7-22 Section 12.8.7 requires that the stability coefficient θ = Px × Δ × Ie / (Vx × hsx × Cd) ≤ 0.10 (or θmax = 0.5/(β × Cd) ≤ 0.25). If θ > 0.10, member forces and drifts must be amplified by 1/(1 − θ).

Steel framed walls serve two distinct roles in construction: as lateral force-resisting elements (steel plate shear walls, SPSW) and as non-structural or lightly-structural partitions (cold-formed steel stud walls). This reference covers both systems, their design provisions, and the practical engineering checks required for each.

Steel plate shear walls (SPSW) per AISC 341

A steel plate shear wall consists of a thin steel infill plate bounded by boundary columns (called vertical boundary elements, VBE) and boundary beams (horizontal boundary elements, HBE). Under lateral load, the thin plate buckles and develops a diagonal tension field that resists story shear.

Design principles

The infill plate is designed to yield in tension along the diagonal. The capacity per AISC 341-22 Section F5 is:

Vn = 0.42 * Fy * tw * Lcf * sin(2 * alpha)

where:

F_y = plate yield strength (typically A36, Fy = 36 ksi)
t_w = plate thickness
L_cf = clear span between VBE flanges
alpha = angle of tension field from vertical (approximately 40-45 degrees for typical geometry)

Worked example — SPSW infill plate sizing

Given: 3-story building, SDC D. Story shear at Level 2: V_u = 480 kips. Bay width = 20 ft (L_cf = 19 ft = 228 in. after deducting column flanges). Story height = 13 ft. A36 infill plate. R = 7, Omega_0 = 2 (SPSW system factors per ASCE 7 Table 12.2-1).

Step 1 — Required plate thickness: Assuming alpha = 42 degrees: sin(2 * 42) = sin(84) = 0.995

phi _ V_n = phi _ 0.42 _ Fy _ tw * Lcf * sin(2 _ alpha) 480 = 0.90 _ 0.42 _ 36 _ t*w * 228 _ 0.995 480 = 0.90 _ 3,445 _ t_w 480 = 3,100 * t_w t_w = 480 / 3,100 = 0.155 in.

Use 3/16 in. (0.1875 in.) plate. This is close to the practical minimum for welded plate construction.

Step 2 — VBE (column) design: The boundary columns must resist the horizontal component of the tension field plus frame action. Per AISC 341 Section F5.4b, the VBE must be designed for the forces corresponding to full yielding of the infill plates above and below, using Ry * Fy (expected yield = 1.5 * 36 = 54 ksi for A36).

Step 3 — HBE (beam) design: The boundary beams must transfer the tension field forces from the plate to the columns. They experience both the uniform pull from the tension field (acting like a beam on elastic foundation) and the frame moments from lateral drift.

Cold-formed steel (CFS) stud walls

CFS stud walls use light-gage steel framing (typically 20-12 gage, 33-50 ksi) for interior partitions, exterior curtain walls, and load-bearing walls in low-rise construction.

Design per AISI S100 and S240

CFS studs act as columns subject to axial load and/or beam-columns when wind or seismic out-of-plane loading is present. Key limit states include:

Flexural buckling (Euler column buckling about the weak axis)
Flexural-torsional buckling (for singly-symmetric C and Z studs)
Distortional buckling (lip/flange distortion, unique to CFS)
Local buckling (flat element buckling)

Worked example — CFS exterior stud wall

Given: 600S162-54 stud (6 in. deep, 1.625 in. flange, 54 mil = 0.054 in., Fy = 50 ksi). Stud height = 12 ft. Studs at 16 in. o.c. Wind pressure = 25 psf. Axial dead load from parapet = 200 lb per stud. Bridging at mid-height and third points.

Step 1 — Section properties (from AISI S100 tables): A_g = 0.840 in.^2, I_x = 5.91 in.^4, S_x = 1.97 in.^3, r_x = 2.65 in., r_y = 0.727 in.

Step 2 — Axial capacity (weak axis governs with bridging at third points): Unbraced length for weak axis: L_y = 12/3 = 4 ft = 48 in. (bridging at third points) KL/r_y = 1.0 * 48 / 0.727 = 66.0

F*e = pi^2 * E / (KL/r)^2 = pi^2 _ 29500 / 66^2 = 291,100 / 4,356 = 66.8 ksi lambda_c = sqrt(Fy / F_e) = sqrt(50 / 66.8) = 0.865

Since lambda*c <= 1.5: F_n = 0.658^(lambda_c^2) * Fy = 0.658^0.748 _ 50 = 0.718 * 50 = 35.9 ksi

phi _ P_n = 0.85 _ 35.9 * 0.840 = 25.6 kips >> 0.200 kips (axial demand trivially low)

Step 3 — Flexural capacity (strong axis, wind loading): M*u = w * L^2 / 8 = (25 _ 16/12) / 1000 _ 144^2 / 8 = 0.0333 _ 20,736 / 8 = 86.3 kip-in. Wait — recalculate:

w = 25 psf _ (16/12 ft) = 33.3 lb/ft = 0.0333 kip/ft M_u = 0.0333 _ 12^2 / 8 = 0.0333 * 144 / 8 = 0.600 kip-ft = 7.2 kip-in.

phi _ M_n = 0.90 _ Fy _ S_e (effective section modulus for local buckling check) For this stud with Fy = 50 ksi, S_e approximately = 1.85 in.^3 (slight reduction from local buckling) phi _ M*n = 0.90 * 50 _ 1.85 = 83.3 kip-in. >> 7.2 kip-in. (OK)

Step 4 — Combined axial + bending interaction (AISI S100 Section C5.2.2): Pu / (phi * Pn) + M_u / (phi * M_n) = 0.200/25.6 + 7.2/83.3 = 0.008 + 0.086 = 0.094 < 1.0 (OK — stud is adequate with significant reserve)

Code comparison

Aspect	AISC 341 (SPSW) / AISI S100 (CFS)	EN 1998-1 / EN 1993-1-3	AS 4100 / AS 4600	CSA S16 / CSA S136
SPSW provisions	AISC 341 Section F5	EN 1998-1 Section 7 (limited)	Not widely codified	CSA S16 Clause 27.9
SPSW R factor	7.0	q approximately 5-6	Not defined (rare use)	Rd * Ro = 5.0 * 1.6
CFS stud design	AISI S100-22	EN 1993-1-3	AS/NZS 4600	CSA S136-16
Distortional buckling	AISI S100 Appendix 2	EN 1993-1-3 Section 5.5	AS 4600 Section 3	CSA S136 Section C
CFS seismic	AISI S400	EN 1998-1 (general)	No specific standard	AISI S400 (adopted)

Key clause references

AISC 341-22 Section F5 — Steel plate shear wall design
AISI S100-22 — North American Specification for CFS structural members
AISI S240 — CFS framing standard (connection and assembly provisions)
AISI S400 — Seismic design of CFS lateral systems
IBC Section 2211 — CFS construction requirements
EN 1993-1-3 — Supplementary rules for cold-formed members

Topic-specific pitfalls

Using A992 plate for SPSW instead of A36 — A36 plate (Fy = 36 ksi) is preferred because the lower yield strength produces a thinner tension field, reducing demands on boundary elements. A992 (Fy = 50 ksi) plate results in higher overstrength demands on the columns and beams.
Ignoring distortional buckling in CFS stud design — traditional effective width methods miss the distortional buckling mode (lip-flange rotation). AISI S100 Appendix 2 provides the Direct Strength Method (DSM), which captures all three buckling modes (local, distortional, global). Omitting the distortional check can be unconservative by 10-20%.
Not providing CFS bridging at the specified intervals — without bridging, the weak-axis unbraced length equals the full stud height, and flexural-torsional buckling capacity drops dramatically. Bridging must be installed before load is applied.
Detailing SPSW fish plate connections without accounting for plate overstrength — the welds or bolts connecting the infill plate to the boundary elements must develop Ry * Fy * t_w (expected yield of the plate), not just the design force. For A36 plate, R_y = 1.5, so the connection demand is 1.5 * 36 = 54 ksi times the plate area.

Stud wall design per AISI S100

Cold-formed steel (CFS) stud walls are designed per AISI S100 (North American Specification for the Design of Cold-Formed Steel Structural Members) and AISI S240 (Standard for Cold-Formed Steel Framing). The design process involves checking multiple limit states that do not occur in hot-rolled steel design, including distortional buckling and local buckling of thin elements.

Design procedure summary:

Determine factored loads (axial, bending, shear) from gravity and lateral analysis
Select a trial stud size and compute full section properties
Calculate effective section properties using the effective width method (AISI S100 Section B2) or the Direct Strength Method (AISI S100 Appendix 2)
Check each limit state: global buckling, local buckling, distortional buckling, and their interactions
Check combined axial and bending interaction (AISI S100 Section C5.2)
Verify deflection limits under service loads

Stud size selection table

Stud Designation	Depth (in)	Flange (in)	Thickness (mil/in)	Fy (ksi)	Ag (in²)	Ix (in⁴)	Sx (in³)	Max Span (ft)¹
800S162-33	8.0	1.625	33 / 0.0346	33	0.531	4.32	1.08	10-12
800S162-43	8.0	1.625	43 / 0.0451	33	0.692	5.63	1.41	12-14
800S162-54	8.0	1.625	54 / 0.0566	50	0.840	5.91	1.97	14-16
800S162-68	8.0	1.625	68 / 0.0713	50	1.054	8.67	2.17	16-18
1000S162-43	10.0	1.625	43 / 0.0451	33	0.747	9.14	1.83	14-16
1000S162-54	10.0	1.625	54 / 0.0566	50	0.939	11.42	2.28	16-18
1000S162-68	10.0	1.625	68 / 0.0713	50	1.174	14.26	2.85	18-20
1000S162-97	10.0	1.625	97 / 0.1017	50	1.674	20.13	4.03	20-22
1200S200-54	12.0	2.0	54 / 0.0566	50	1.115	19.76	3.29	18-20
1200S200-68	12.0	2.0	68 / 0.0713	50	1.395	24.70	4.12	20-22
1200S200-97	12.0	2.0	97 / 0.1017	50	1.989	34.92	5.82	24-26

¹ Max span assumes wind load of 25-30 psf, L/240 deflection limit, studs at 16" o.c. Actual spans vary with loading and deflection criteria.

Deflection limit criteria for CFS stud walls

Deflection limits for CFS wall systems are dictated by the supported cladding type and the wall's function (curtain wall vs. load-bearing):

Wall Type / Cladding	Deflection Limit	Basis
Curtain wall (glass)	L/175 to L/240	Glass industry standards (AAMA)
Curtain wall (metal panels)	L/120 to L/180	Metal panel manufacturer specs
Curtain wall (brick veneer)	L/360 to L/600	Brick Institute (BIA) requirements
Curtain wall (EIFS/stucco)	L/240 to L/360	Stucco crack prevention
Load-bearing (gypsum board)	L/180 to L/240	IBC Table 1604.3
Load-bearing (exterior wall)	L/180 to L/360	IBC Table 1604.3
Party wall / fire wall	L/240 to L/360	Project-specific

The controlling deflection limit is typically L/360 for walls supporting brittle finishes (gypsum, plaster, masonry veneer) and L/180 for walls with flexible finishes. Wind load for deflection checks uses the 10-year or 25-year return period wind speed (not the 50-year strength-level wind), per ASCE 7 Commentary.

Curtain wall vs load-bearing wall

Aspect	Curtain Wall Stud	Load-Bearing Stud
Primary load	Wind pressure (out-of-plane)	Gravity axial + wind bending
Stud size	600S-33 to 800S-54 (lighter)	800S-54 to 1200S-97 (heavier)
Typical spacing	16" or 24" o.c.	12" or 16" o.c.
Deflection limit	L/180 to L/360	L/240 to L/360
Bridging requirement	At mid-height minimum	At third points or quarter points
Top track	Slip track (allows deflection)	Standard track (rigid connection)
Design code	AISI S100 / AISI S220 (curtain wall)	AISI S100 / AISI S240
Bottom track	Standard track	Reinforced track for bearing
Stud thickness	33-54 mil (20-16 ga)	54-97 mil (16-12 ga)

Curtain wall studs are designed for wind pressure as pure flexural members. The top track is typically a "slip track" or "deflection track" that allows the building frame to deflect under gravity loads without transferring axial load to the studs. Load-bearing studs are designed as beam-columns for combined axial compression and wind bending.

Typical spans by stud depth

Practical span capabilities for CFS studs at 16" o.c. with 25 psf wind load and L/240 deflection limit:

Stud Depth	33 mil (20 ga)	43 mil (18 ga)	54 mil (16 ga)	68 mil (14 ga)	97 mil (12 ga)
3.625"	8-9 ft	9-10 ft	10-11 ft	11-12 ft	12-13 ft
6.0"	11-13 ft	13-15 ft	15-16 ft	16-18 ft	18-20 ft
8.0"	14-16 ft	16-18 ft	18-20 ft	20-22 ft	22-24 ft
10.0"	17-19 ft	19-22 ft	22-24 ft	24-26 ft	26-28 ft
12.0"	20-23 ft	23-26 ft	26-28 ft	28-30 ft	30-33 ft

These spans are approximate and controlled by deflection. Strength (bending capacity) rarely governs for curtain wall applications but may govern for load-bearing walls with heavy axial loads.

Connections: track, bridging, and bracing

Track connections: CFS studs are seated in top and bottom tracks (U-shaped channels). The stud-to-track connection at the ends provides nominal rotational restraint but is typically modeled as a pin for design. For load-bearing walls, the bottom track must transfer the stud reaction to the supporting structure. Clip angles or gusset plates reinforce this connection when loads exceed the track's web crippling capacity.

Bridging types:

Bridging Type	Description	Restraint Provided
Flat strap	1-1/2" min wide metal strap across stud flanges	Lateral bracing only
U-channel bridging	Channel bridging member through stud punchouts	Lateral + torsional restraint
Channel + flat strap	Channel through punchouts + strap on outside flange	Full restraint
Solid blocking	CFS track or stud sections between studs at bridging points	Full restraint + shear transfer
Hat channel bridging	Hat-shaped section screwed to stud flanges	Lateral + torsional restraint

Bridging spacing: AISI S100 requires that the bridging spacing not exceed the spacing at which the stud's weak-axis buckling capacity drops below the design demand. In practice, bridging is provided at 4-6 ft intervals for 8" studs and 5-8 ft intervals for 10-12" studs.

Thermal performance considerations

Steel studs are highly conductive (k = 310 BTU/hr-ft-°F) compared to wood studs (k = 0.8) or insulated cavities (k = 0.03). This creates thermal bridging through the stud, reducing the effective wall R-value significantly:

Wall Assembly	Cavity R-value	Effective R-value	Reduction
6" stud, R-19 cavity insulation, no exterior insulation	19	7-9	53-63%
6" stud, R-19 cavity, 1" XPS exterior	19 + 5	15-17	30-40%
6" stud, R-19 cavity, 2" XPS exterior	19 + 10	22-25	14-27%
8" stud, R-25 cavity, 1.5" polyiso exterior	25 + 9.5	22-26	17-30%

To mitigate thermal bridging, continuous exterior insulation (rigid foam board or mineral wool) is specified on the outboard side of the studs. The 2021 IECC requires continuous insulation in most climate zones for steel-framed walls. The colder the climate zone, the more continuous insulation is required. Thermal performance does not affect the structural design of the studs but is a critical building envelope consideration.

Run this calculation

Related references

Disclaimer

This page is for educational and reference use only. It does not constitute professional engineering advice. All design values must be verified against the applicable standard and project specification before use. The site operator disclaims liability for any loss arising from the use of this information.

[object Object]

Frequently Asked Questions

What is the recommended design procedure for this structural element?

The standard design procedure follows: (1) establish design criteria including applicable code, material grade, and loading; (2) determine loads and applicable load combinations; (3) analyze the structure for internal forces; (4) check member strength for all applicable limit states; (5) verify serviceability requirements; and (6) detail connections. Computer analysis is recommended for complex structures, but hand calculations should be used for verification of critical elements.

How do different design codes compare for this calculation?

AISC 360 (US), EN 1993 (Eurocode), AS 4100 (Australia), and CSA S16 (Canada) follow similar limit states design philosophy but differ in specific resistance factors, slenderness limits, and partial safety factors. Generally, EN 1993 uses partial factors on both load and resistance sides (γM0 = 1.0, γM1 = 1.0, γM2 = 1.25), while AISC 360 uses a single resistance factor (φ). Engineers should verify which code is adopted in their jurisdiction.