The transition from the manufacturing plant to the construction site is a critical phase. While COMSA Steel joists are engineered for strength, they reach their full structural capacity only once they are properly installed, braced, and integrated into the building’s diaphragm. Because joists are “deep and narrow” members, they are inherently unstable until they are permanently braced. Following strict erection protocols is not just about project efficiency—it is about life safety.

1. Receiving and On-Site Handling

Safety begins the moment the truck arrives. Joists should be unloaded by the ends of the top chords at the panel points to avoid bending or “kinking” the lighter web members. At COMSA Steel, we recommend storing joists in an upright position. If they must be stored flat, they should be supported on dunnage (wooden blocks) to prevent moisture buildup and ground-contact corrosion.

2. The Hoisting Process

Before lifting, the erector must verify the weight of the joist or joist bundle. Using a crane with the appropriate capacity is the first step in a safe lift.

• Stable Picking: Joists should be hoisted using a “spreader bar” or a two-point sling. This prevents the joist from bowing or twisting mid-air, which could cause a sudden shift in the load.
• Tag Lines: No joist should be lifted without tag lines. These allow ground crews to control the rotation of the joist from a safe distance, especially in windy conditions typical of open-site construction.

3. Landing and Initial Attachment

A joist is most vulnerable the moment it is set onto its supports (beams or masonry walls).

• Minimum Bearing: According to SJI (Steel Joist Institute) standards, a K-Series joist must have a minimum of 2.5 inches of bearing on steel supports (4 inches on masonry).
• Immediate Securing: The joist “seats” must be either bolted or “tack-welded” immediately upon landing. A joist that is simply “resting” on a beam is a hazard that can be easily dislodged by a gust of wind or an accidental bump from a nearby worker.

4. The Critical Role of Bridging

Bridging is the secondary steel—either horizontal bars or cross-diagonal angles—that connects adjacent joists. Its primary purpose is to prevent the joist from “rolling” or buckling sideways under load.

• Sequential Installation: Bridging must be installed and anchored before any construction loads (like bundles of roof decking) are placed on the joists.
• The “First Row” Rule: In many long-span applications, the first row of bridging must be installed before the hoisting cables are even released from the joist. This ensures the member is laterally stable before it is left to stand on its own.

5. Fall Protection and Walking the Steel

Modern safety standards (such as OSHA in the U.S. or equivalent local regulations) strictly govern how workers move across steel. Joists are not designed to be “walked” until they are fully bridged and anchored. We encourage the use of perimeter cables, personal fall-arrest systems, and aerial lifts to ensure that the installation team remains protected at all times.

6. Avoiding Overload During Construction

One of the most common causes of site accidents is the improper placement of construction materials. Bundles of steel decking should never be dropped onto unbridged joists. COMSA Steel provides clear loading diagrams to ensure that the weight of raw materials is distributed across the “panel points” of the joists, where the structure is strongest.

The COMSA Commitment to Field Success

A successful project ends when every worker goes home safely and the structure stands true. By adhering to SJI erection standards and maintaining clear communication between the COMSA Steel engineering team and the site erectors, we ensure that the high-quality engineering of our shop translates into a high-quality building in the field.