Composite joists and deck optimize multi-story projects

Composite Joist System

Create the longest spans possible

Composite Joist and Deck
Composite joists and deck can reduce floor-to-floor height, costs, construction timelines and required steel material

Capable of open spans of up to 60 feet and beyond, composite steel joist and steel deck long-span composite floor systems provide design flexibility while introducing a range of cost and performance enhancements.

This steel building system derives its strength in two ways: The composite joist’s (CJ-Series) shear connection to the overlying concrete slab and the composite deck’s bond with the concrete slab. The shear connection is a result of field-applied shear studs that become embedded in hardened concrete when the composite decking is filled with concrete. The composite deck itself has embossments in the vertical ribs that bond with the concrete slab to develop a composite floor system.

Cost- and space-efficient

The result is stronger, stiffer, lighter and less costly than other structural steel frame approaches in multi-story construction. The efficiency of the system is demonstrated by the increase in headroom that can be achieved with no loss in the length of the joist span. For example, a 48-foot span can be achieved with a 24-inch deep, non-composite joist, whereas the same 48-foot span can be achieved with a composite joist with only a 20-inch depth.

Drawing of Composite Joists
  • MEP routing through joist webbing optimizes ceiling height
  • Wider spaced and fewer columns for more open bays
  • Reductions in steel material, timeline and related costs
  • Stiffer floors for reduced live load deflections and reduced vibration
Find us in ARCAT Find us in Deltek Specpoint
CJ-Series catalog

Weight tables, bridging tables and codes of standard practice for composite joists available in the Steel Joist Institute CJ-Series catalog.

Credit hour: Multi-story systems

Earn credit and gain an in-depth understanding of our three long-span composite floor systems.

Composite deck is versatile

New Millennium engineers and manufactures a wide range of composite deck products and systems ideal for various project types.

Case Study
Cauley Ferrari dealership
Supporting 292,000 pounds for cars

What makes a second-floor showroom full of Ferraris possible? Just 28-inch composite joists and 5 inches of composite deck.

New Millennium can provide design assistance and help you choose the ideal system for your project. Contact one of our specialists to get started.

Cover of Long-span Composite Systems Brochure
Long-span composite systems brochure

A composite joist and deck long-span composite floor system is one of our three systems for multi-story construction.

Building a better steel experience