Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

March 16, 1981

MEMORANDUM TO:      John Miles
                   Director, Office of Field Coordination

FROM:               Allan E. Martin
                   Director, Office of Construction and
                   Civil Engineering Safety Standards

SUBJECT:            Application of 1926.500(g)(1)

As requested, following are this office's comments on certain built-up roofing requirements. During the performance of built-up roofing work, which includes related sheet metal work, employees engaged in such work shall be protected as follows:

1. By use or a motion-stopping system; or

2. By use of a warning line system supplemented with either an MSS system or safety monitoring system; or

3. By use of a safety monitoring system on roofs fifty feet or less in width, where mechanical equipment is not being used or stored.

Consequently, when an employer elects to use the warning line system and/or safety monitoring system the use of an MSS system (safety belts, guardrails, etc.) is not required.

As stated in the preamble to the regulation, the individual designated to be the monitor "may have supervisory or non-supervisory responsibilities as there are no restrictions on the performance of other duties. (It is obvious, however, that the monitor must not be so busy with other responsibilities that the monitoring function is encumbered)." In other words, the monitor may be a working member of the crew so long as he is on the same roof, within visual sighting distance, and close enough to be able to verbally communicate with the other crew member(s) when it appears that the other crew member(s) is unaware of the hazard or is acting in an unsafe manner.