Mortar strength notification before steel erection

May 21, 2003

Rashod R. Johnson
Director of Engineering
Mason Contractors Association of America
[Recipient address omitted]

Re: Requirement in 29 CFR 1926.752 for steel erector to obtain written notification of strength test for mortar in masonry piers/walls prior to steel erection.

Dear Mr. Johnson:

This letter responds to your September 3, 2002, inquiry regarding some of the provisions in the steel erection standard and some other issues. We have paraphrased your questions as follows:

Question: Under the steel erection standard, prior to beginning steel erection on a masonry wall, the steel erector must obtain written notification that the mortar has reached sufficient strength in accordance with the appropriate ASTM test standard. However, there is no ASTM test standard for mortar curing. What, then, is a steel erector required to do in this regard?

Answer

Section 1926.752(a)(1) requires that before authorizing the commencement of steel erection, the controlling contractor must ensure that the steel erector is provided with written notification indicating that:

> 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.

At §1926.752(b) the standard prohibits a steel erector from erecting steel

> unless it has received written notification that the … mortar in the masonry piers and walls has attained, on the basis of an appropriate ASTM standard test method of field-cured samples, [adequate strength].

As the Mason Contractors Association of America (MCAA) and others have indicated, there is no appropriate ASTM standard test method for assessing compressive strength of field-cured mortar. We understand that ASTM C780-Method for Preconstruction and Construction Evaluation of Mortars for Masonry - assesses field-mixed mortar consistency, not its compressive strength, and does not entail testing field-cured samples as required by Subpart R.

As we recently stated in the Purcell letter, (see copy attached):

> Since there currently is no ASTM standard test method to test the compressive strength of field-cured mortar, OSHA will not enforce the requirements of §1926.752(a)(1) until such time as we are able to define an appropriate substitute or until an appropriate ASTM test method is developed.

Likewise, OSHA will not enforce the requirement in §1926.752(b) prohibiting the erector from beginning steel erection until receiving that mortar strength notification or until such time as the Agency is able to define an appropriate substitute or until an appropriate ASTM test method is developed.

Other Matters

Silica Stakeholder List
As you requested, we have added the MCAA's Washington representative, Marian Marshall, to the Occupational Safety and Health Administration's (OSHA) silica stakeholders list. We appreciate MCAA's interest in the issues surrounding silica in the construction workplace.

Advisory Committee E-mail List
In addition, MCAA asked that Ms. Marshall be placed on notification lists for OSHA committee meetings that pertain to the construction industry as a whole. OSHA's Advisory Committee for Construction Safety and Health (ACCSH) is charged with advising OSHA on matters pertaining to the construction industry. We have added Ms. Marshall to the Directorate of Construction's e-mail notification list for ACCSH and ACCSH work group meetings. Mr. Steve Cloutier of my staff is the point of contact for ACCSH and ACCSH work group meetings.

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