Steel Composite Joists are an open web system combined with a concrete slab that acts like a composite top chord for the underlying steel joists, exhibiting a stiffer response to applied loads compared to conventional steel joist systems. Shear transfer from the concrete slab to the underlying steel joists is accomplished by welding or screwing in a shear connector through the steel deck to the steel joist top chord. Composite Joists are economical because they can reduce floor-to-floor heights by allowing MEP to be routed through the open webs. They are also ideal for use in projects where large column-free areas are desired.
Understanding Joist Designations
The image at left provides the breakdown of how to properly designate a composite joist. Vulcraft provides an easy to follow process for determining the proper loading criteria for the designation based on the project’s requirements.
COMPOSITE JOIST PROFILES
CJ-SERIES
Vulcraft's CJ-Series Joists are designed to provide optimal strength and versatility in various construction projects. These joists, also known as Composite Joists, combine the efficiency of a steel open web system with the benefits of concrete slab construction.
For technical information, including loading capacity information, please refer to our Technical Information. While this information is for common situations, not every project is common. For answers to any questions, please reach out and TALK TO AN EXPERT.
UTILIZING OUR DESIGN TOOLS
Vulcraft’s Design Tools allow you, as the designer, to obtain custom design information for your project, look at scenarios, and allow you to find the highest value solutions for your project.
DYNAMIC JOIST WIZARD
Turn your combined uniform and concentrated loading into shear and moment diagrams. Other outputs include suggested joist designation, bridging requirements, and maximum chord width.
ECOSPAN® FLOOR SYSTEM ESTIMATING AID
Interested in how Ecospan® compares to other floor systems? This tool will help you determine depths, joist designations, joist/deck dead loads, fastener patterns, flush-plate connection checks, maximum ductwork, and much more.
ADDITIONAL TOOLS
Our Joist Design Tools can help you find the most economical joist depths, perform shear and moment comparisons, analyze vibration, and much more.
ECOSPAN® FLOOR SYSTEM
Another option that uses composite joists is our Ecospan® Structural Floor System, which uses a Shearflex fastener instead of a welded shear stud. The self-tapping, self-drilling heat treated Shearflex® fastener not only attaches the deck to the joists but also acts as the shear connector between the steel and the concrete. Click here for more on the Ecospan® Structural Floor System.
ADDITIONAL RESOURCES
ADDITIONAL RESOURCES
In accordance with the standards set by the Steel Joist Institute (SJI), Vulcraft manufactures a full range of joists, including standard joists, joist girders, and composite joists, designed to work compositely with the concrete slab that is placed on top of the steel deck, creating a very efficient floor system.
For additional selection, specification, and detailing information find us at: 
COMPOSITE JOIST
LOAD TABLES
CJ-SERIES LOAD TABLES
- LRFD Weight Table (Normal Weight Concrete)
- LRFD Bridging Table (Normal Weight Concrete)
- LRFD Weight Table (Light Weight Concrete)
- LRFD Bridging Table (Light Weight Concrete)
CJ-SERIES DATASHEETS
- Accessories/Details
- Fire Resistance Ratings
- OSHA Safety Standards
- CJ Series Standard Specifications
- Standard Construction Specification
- Code of Standard Practice
- Composite/Noncomposite Glossary
- Design Example – Uniformly Distributed Loading
- Design Example – Special Loadings
