Structural Stud design tools and tables

Structural Studs, may be used in a variety of applications and designs. While most conditions require the expertise of a design professional, many systems can be selected based on tabulated data or design tools. Locate the required assembly below and follow the instructions for selecting the proper design criteria.

Select one of the design criterias below for more info:

Interior Walls w/Structural Framing (Nonstructural / Non-load bearing)

Design Tools:

Limiting Height Tables:

Typically ProSTUD Drywall Framing is used for interior walls but the use of structural framing may be needed to meet taller requirements. Interior nonstructural (non-load bearing) walls calculated in the Structual Stud Lookup Tool and Limiting Height Tables are limited to a superimposed axial load, exclusive of sheathing materials, of not more than 100 lb/ft, or a superimposed axial load of not more than 200 lbs.

Lateral Load / Design Load

Nonstructural (Non-load bearing) interior walls must be designed to withstand a minimum of 5 psf lateral load (perpendicular to the wall) for interior pressure as required by the International Building Code. Check your projects Architectural Specifications and/or drawings for the minimum design load required. Loads of 7.5psf and 10psf are typically used for shaftwalls or interior lobby walls located in floors with multiple exterior doors.

Deflection

The main purpose of specifying an allowable stud lateral deflection for interior wall framing is actually for determining what is an acceptable deflection for the wall facing materials. Sheathing and Finish materials require a minimum stiffness to prevent cracking. The required stiffness for the finish material is achieved by the specified deflection limit. Check with your projects Architectural Specifications and/or drawings for the lateral deflection required for a given wall facing material. Interior walls typically require a minimum lateral deflection of L/240. Some finishes such as tile or thin stone may require a higher deflection limit like L/360 or even L/600. We do not recommend using L/120 for walls taller than 10 feet.

For example a 10’ wall at L/120 (L = Length in inches, divided by 120) could have a lateral deflection of (10x12/120) = 1"

Limiting Heights

Limiting heights are based on continuous lateral support (gypsum wallboard) on each flange over the full height of the stud. If wallboard does not run the full height of the stud, lateral bracing may be required. Contact ClarkDietrich Technical Services to help determine spacing of the lateral bracing above the wallboard.

See all design notes on the bottom of the lookup tool and tables.

Exterior Curtain Walls

Design Tools:

Limited Height Tables:

Curtain Wall Framing Systems support the exterior skin or cladding of commercial and industrial buildings. The studs for these framing systems must be able to withstand:

  • The weight of the cladding material (metal, stone, tile, etc.).
  • The wind loads to which they will be subjected.

Exterior curtain walls are non-axial load bearing and must be designed to withstand the highest lateral loads, wind or seismic, prescribed by the building code for the particular construction location and type. Limited heights in the above lookup tool and tables are for single span systems only. It is recommended to have a vertical deflection gap between the top of the stud and top track for primary structure movement as required by the E.O.R. A deep leg deflection track system is used in this condition.

Lateral Load / Design Load

Exterior curtain walls must be designed to withstand the highest lateral loads anticipated for the particular construction location and type. Wind pressures can be found in the project's structural drawings under the “general notes” section. Required lateral loads for design must be provided by the E.O.R. or the Specialty Engineer.

Load/Span Table Wind Pressure Notes

IBC 2012/ASCE 7-10 only

Due to changes in the model building codes, design wind pressures determined using IBC 2012/ASCE 7-10 are strength level loads (LRFD) in comparison to those determined in earlier IBC codes which were service level loads (ASD). The load/span tables that are in this lookup tool are based on service level (ASD) wind loads. Therefore, to properly use the load/span tables in this tool, multiply the IBC 2012/ASCE 7-10 design wind pressures by 0.6 (reference section 2.4 ASCE 7-10) prior to entering the load/span tables.

Example:
ASCE 7-10 Calculated Design Wind Pressure = 16psf (strength level loads, LRFD)
Convert to service level load (ASD) = 16psf x 0.6 = 10psf
Use 10psf as the Pressure Value used in this table to determine the member span

Any other building code

The load/span tables that are in this lookup tool are based on service level (ASD) wind loads. If the wind load being used meets this criterion, it does not need to be modified prior to using the tables.

Deflection

The main purpose of specifying an allowable stud deflection for curtain wall framing is actually for determining what is an acceptable deflection for the wall facing materials. A metal stud is ductile and therefore can perform at a wide range of deflections. Wall facing materials tend to be more brittle (Brick, Stucco or EIFS), and thus have a more stringent maximum allowable deflection. The project architect or project specifications should note what the allowable deflection is for a given wall facing material.

Typical Deflection Requirements: (L = Length in inches)

  • L/240 Exterior siding or EIFS
  • L/360 Exterior stucco
  • L/600 Exterior brick or stone
  • L/720 Exterior brick or stone

For example a 20’ wall at L/240 (L = Length in inches, divided by 240) could have a lateral deflection of (20x12/240) = 1”.

Limiting Heights

Limiting heights are based on continuous lateral support (rigid sheathing) on each flange over the full height of the stud. Horizontal structural bridging (or bracing) is defaulted to be at 4 ft. on center for the purposes of the values shown in the lookup tool and tables. The actual bridging that is ultimately provided is to be determined by the licensed specialty engineer responsible for the cold-formed steel design for the given project. Contact ClarkDietrich Technical Services to help determine maximum spacing of the lateral bracing.

Adding additional horizontal bridging will not reduce the actual deflection in the wall. To reduce the deflection of a wall stud, either a heavier member is required or an intermediate structural support must be provided.

See all design notes on the bottom of the lookup tool and tables.

Interior and Exterior Load Bearing Walls

Design Tables:

Load-bearing walls must be capable of handling vertical loads even when subjected to lateral loads from wind or another force. The following tables identify the axial (vertical) load that can be supported by each member under given lateral load conditions.

General Notes:

  • Allowable axial loads determined in accordance with section C5 of AISI S1007, with section D4 used for treatment of punchouts, and assuming that all axial loads pass through centroid of effective section.
  • Listed lateral pressures and axial loads have not been modified for 1/3 stress increase based on wind/earthquake or multiple transient loads.
  • Allowable loads based on weak axis and torsional horizontal mechanical bracing at 48" o.c. maximum for axial load calculations, and continuous support for each flange for flexural calculations.
  • With the exception of 5psf interior walls, wind pressures have been multiplied by 0.70 for deflection determination, in accordance with footnote “f” of IBC table 1604.3.
  • The strength increase due to cold work of forming was incorporated for flexural strength as applicable per section A7.2 of AISI S100-2007 with 2010 supplement.
  • The allowable axial loads do not include the effects of the sheathing materials.

Need higher performance than conventional “C” shaped studs?

Heavy-Duty Stud (HDS®) alternative cost-effective framing system with superior strength. The superior strength and carrying capacity of the HDS means higher performance with fewer members. It eliminates box beam headers, stud-to-track nesting, built-up members for posts and jambs and has superior axial strength for load-bearing projects.

HDS Allowable Limiting Heights

Full structural framing technical design guide

While this Design Guide Catalog is quite comprehensive, it does not completely cover our vast and growing lineup of products or design tables. To keep the catalog from being overloaded, it only includes half the design tables our online tools can offer. Please conceder using ClarkDietrich iTools.