Concrete-strength notice for steel erected on an old slab

March 10, 2006

Jamie Stevenson

James Construction

[Recipient address omitted]

Re: Whether the notification required in §1926.752(a)(1) (attained concrete strength) must be given where steel will be erected on a long-existed concrete slab.

Dear Mr. Stevenson:

This is in response to your May 19, 2005 e-mail to John McFee of the Occupational Safety and Health Administration (OSHA), which was forwarded to the Directorate of Construction. We apologize for the delay in responding.

We have paraphrased your question as follows:

Question: Structural steel columns are going to be erected as part of a rehab and expansion project. The columns will be anchored to a concrete slab that was poured years ago when the original structure was built. In this scenario, does the controlling employer have to provide the steel erector with the written concrete strength notification required by §1926.752(a)(1)?

Answer: In the steel erection standard, 29 CFR 1926.752 states:

(a) Approval to begin steel erection. Before authorizing the commencement of steel erection, the controlling contractor shall ensure that the steel erector is provided with the following written notifications:

(1) The concrete in the footings, piers and walls and the mortar in the masonry piers and walls has attained, on the basis of an appropriate ASTM standard test method of field-cured samples, either 75 percent of the intended minimum compressive design strength or sufficient strength to support the loads imposed during steel erection. [Emphasis added.]

The term "attained," in conjunction with alternative measures of strength described in the provision (either 75% of the intended minimum compressive design strength or sufficient strength to support the loads imposed during steel erection), refers to a point in the curing process of concrete. This is also reflected in the discussion of this provision in the final rule's preamble, which states:

The preamble to §1926.752(a) states:

SENRAC found that many accidents involving collapse could have been averted had adequate pre-erection communication and planning occurred [63 FR 43461]. This section of the rule is designed to ensure proper communication and preplanning between contractors pouring concrete footings, contractors making repairs to repairing anchor bolts, the controlling contractor, and the steel erector. This communication must take place prior to the beginning of steel erection. The written notification can be transmitted electronically. [Emphasis added.]

In the scenario you describe, the curing process was completed years before the new steel erection is to begin. Consequently, in this scenario, a failure to provide the notification under §1926.752(a)(1) would be considered a de minimis violation.[1]

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

Sincerely,

Russell B. Swanson, Director

Directorate of Construction

[1] Under OSHA's de minimis policy, de minimis violations are those that have no direct or immediate relationship to safety or health. Consequently, no ciation is issued.