Frequently Asked Questions

Answers to your frequently asked question. Browse by topic or search for your question.


The seat should be welded.

Typically, the joist tag provides information that is useful to the erector in matching a particular joist in the field to a location on the placing plan. If the placing plan or approved field use drawings from the joist manufacturer are available, then the tag information could be useful. If plans are not available, it is possible that the manufacturer may still have helpful information. When all else fails, contact the manufacturer.

The bridging that is required only for erection stability can be removed. However the bridging needed for lateral stability during the life of the joist cannot be removed without an analysis. Generally the deck provided the lateral stability of the top chord so it might be able to be removed. The bridging generally provides the lateral stability of the BC. The removal of this bridging will require an analysis of the loading as well as consultation with the manufacturer.

Bridging is only designed for the lateral stability forces in the joists. In general those values are in the SJI bridging tables in the specification. If bridging is intended to brace other components of the structure the size and connections must be indicated on the contract documents. Normally these systems are independent of the joist system.

Yes, Erection bridging must be installed prior to the hoisting cable being released, consequently if welding is being placed on erection bridging, the welding must be done prior to the hoisting cables being released.

No, KCS joists must be reinforced if the concentrated load is between panel points just like all other joists, unless the load is less than or equal to 100 pounds.

Almost none. Joists are designed for efficiency and a very high strength to weight ratio.

That depends on the bearing depth and type of joist. The manufacturer can provide this information.

That depends on the loads and the configuration of the TCX. Refer to the Top Chord Extension section in the current Specification.

Slots are used due to fabrication and field tolerances. Also, hole to hole connections would encourage using joists to plumb the building.

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