OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.

November 20, 2003

Craig Davis
Safety Coordinator
Doherty Ornamental Iron, Inc.
P.O. Box 428
21110 West 311th Street
Paola, Kansas 66071

Re: Whether it is permissible to weld joists over 40 feet in length (while the hoisting line is kept in place) instead of field bolting them; §1926.757(a)(8).

Dear Mr. Davis:

This is in response to your letter dated July 10, 2003, to the Occupational Safety and Health Administration (OSHA). You ask about the requirements in §1926.757(a)(8)(ii), field bolted joists in bays of 40 feet or more. We apologize for the delay in responding.

We have paraphrased your question as follows:

Question: Section 1927.757(a)(8) requires that joists 40 feet or more be field bolted during erection. Is welding the joists prior to releasing the hoisting cable an acceptable substitute for field-bolting?

Section 1926.757(a)(8) provides:

(i) Except for steel joists that have been pre-assembled into panels, connections of individual steel joists to steel structures in bays of 40 feet (12.2m) or more shall be fabricated to allow for field-bolting during erection.

(ii) These connections shall be field-bolted unless constructability does not allow.

The requirements of §1926.757(a)(8) apply to long and limber joists to ensure that at the critical time of initial connection, the employee is not exposed to a hazard as a result of the joist not being adequately secured upon its placement. In the Preamble of the final rule (volume 66 of the Federal Register, page 5232), OSHA explained this hazard and noted that the risk of collapse arises from a number of causes other than the presence of an employee on a joist. These include wind, accidental movement of the joist by the crane, and accidental impact against the structure by equipment:

The Agency has found that many long steel joists that are placed in bays of 40 feet or more have a greater tendency to twist or rotate, which creates hazards for the workers installing them. This finding was based on several examples of hazardous situations that steel erectors encounter when working with these long joists. The record shows that certain joists that are thin and flexible can be difficult to install because of their "sweep" (tendency to bend). Bolting these types of joists first allows straightening of the joist, correcting its camber and eliminating torque. Additionally, after bolting, final welding can be more easily accomplished. Bolting is safer whenever unattached joists could be displaced by wind or construction activity, by the movement of employees, by trailing welding leads, by accidental impact against the supporting structure by a crane or other equipment, or by harmonic motion, or vibration. Further, joists can roll and pop welds due to the movement of a worker on the joist or the stresses caused by removing the sweep, which could cause a collapse.

Section 1926.757(a)(8)(ii) applies to the initial attachment of these joists. The Agency determined in the rulemaking that considerations of safety require that these joists be bolted rather than welded for their initial attachment (see 66 FR 5236).

In addition, under §1926.757(b)(3), joists must be attached, at least at one end,
1 "immediately upon placement in the final erection position and before additional joists are placed." Since the standard requires that these joists be field-bolted immediately upon placement, that initial attachment is required to be made before the hoisting line is released.

Therefore, when hoisting joists into position, keeping the hoisting line in place while the initial attachment is being made is not a precaution that goes beyond the standard - it is a requirement. Consequently, keeping the hoisting line in place would not be a basis for allowing these joists to be initially attached by welding rather than the required bolting.

If you need additional information, please contact us by fax (202-693-1689) at: U.S. Department of Labor, OSHA, Office of Construction Standards and Guidance. You can also contact us by mail at U.S. Department of Labor, OSHA, Office of Construction Standards and Guidance, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction



1 At both ends for joists over 60 feet, pursuant to §1926.757(c)(2). [back to text]