817 Steel Erection Safety

Beams and Columns

Installing Stabilizing Joists

When installing the stabilizing joist:

• Provide a vertical stabilizer plate for steel joists on each column, which must:
• Be at least 6 inches by 6 inches.
• Extend at least 3 inches below the bottom chord of the joist.
• Have a 13/16-inch hole to provide an attachment point for guying or plumbing cables.

• Stabilize the bottom chords to prevent rotation during erection.
• Do not release hoisting cables until:
• The seat at each end of the steel joist is field-bolted.
• Each end of the bottom chord is restrained by the column stabilizer plate.
• EXCEPTION: Where constructability does not allow a steel joist to be installed at the column, install an alternate means of stabilizing joists on both sides near the column that must:
• Provide equivalent stability to a steel joist field-bolted at the column.
• Be designed by a qualified person.
• Be shop-installed.
• Be included in the erection drawings.

• Do not release hoisting cables until the seat at each end of the steel joist is field-bolted and the joist is stabilized.
• Where steel joists at or near columns span 60 feet or less, the joist must be designed with sufficient strength to allow one employee to release the hoisting cable without the need for erection bridging.
• Where steel joists at or near columns span more than 60 feet:
• The joists need to be set in tandem with all bridging installed.
• An alternative method of erection may be used, which:
• Provides equivalent stability to the steel joist.
• Is designed by a qualified person.
• Is included in the site-specific erection plan.

• A steel joist or steel joist girder must not be placed on any support structure that is not stabilized.
• When steel joists are landed on a structure, they must be secured to prevent unintentional displacement prior to installation.

• When connecting individual steel joists to steel structures in bays 40 feet or longer (see exception below):
• The connections must be fabricated to allow for field-bolting during erection.
• The connections must be initially field-bolted unless constructability does not allow.
• EXCEPTION: These requirements do not apply when steel joists are pre-assembled into panels.

• Steel joists and steel joist girders must not be used as anchorage points for a fall-arrest system unless written approval to do so is obtained from a qualified person.
• A bridging terminus point must be established before bridging is installed.

Knowledge Check Choose the best answer for the question.