Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents
• Standard Number: 1926.451(a)(1); 1926.451(a)(2); 1926.451(a)(3); 1926.451(a)(4); 1926.451(a)(5); 1926.451(c)(1); 1926.451(c)(1)(ii); 1926.451(g)

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.


April 8, 2005

Mr. Douglas A. Holman
1816 River Bend Road
Sevierville, TN 37876

Re: Tie-in requirements for supported scaffolds; §:1926.451(c)(1)(ii); errors in Non-Mandatory Appendix E.

Dear Mr. Holman:

You have submitted nine letters to the Occupational Safety and Health Administration (OSHA) containing a number of questions on the construction scaffold standard (29 CFR Part 1926 Subpart L).1 We will be responding in a series of separate letters in response; this is the first in that series.

We have paraphrased your questions regarding tying-in scaffolds as follows:

Question 1(a): Section 1926.451(c)(1)(ii) contains criteria establishing tie-in requirements for supported scaffolds with a height to base width ratio of more than four to one. When that criteria is applied to a narrow scaffold (scaffolds with a height to base width ratio of more than 4:1) — for example, a supported scaffold that is 2 feet wide and 40 feet high — the employer would be required to tie, guy, or brace the scaffold at approximately the 8-foot level and then not again until every 20-foot increment.

I believe that this criteria is insufficient and allows for an unsafe condition. Is this, in fact, permitted?

Answer: In your question you focus on §:1926.451(c)(1), which states, in part:
Supported scaffolds with a height to base width (including outrigger supports, if used) ratio of more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing, or equivalent means as follows:
* * *
(ii) Guys ties and braces shall be installed according to the scaffold manufacturer's recommendations or at the closest horizontal member to the 4:1 height and be repeated vertically at locations of horizontal member to the 4:1 height and be repeated vertically at locations of horizontal members every 20 feet or less thereafter for scaffolds 3 feet (0.91 m) wide or less, and every 26 feet (7.9 m) or less thereafter for scaffolds greater than 3 feet (0.91 m) wide....[Emphasis added.]
By its terms, §:1926.451(c)(1)(ii), at levels above the initial tie-in and below the top tie-in, establishes maximum intervals of 20 feet. However, another requirement in Subpart L, §:1926.451(a)(1), states:
Except as provided in paragraphs (a)(2), (a)(3), (a)(4), (a)(5) and (g) of this section, each scaffold and scaffold component shall be capable of supporting, without failure, its own weight and at least 4 times the maximum intended load applied or transmitted to it.
If meeting the capacity requirement in §:1926.451(a)(1) necessitates installing tie-in/guy ties/braces at closer intervals, the employer would be required to do so.

Question 1(b): Non-mandatory Appendix E to Subpart L purports to contain two illustrations of the maximum vertical tie spacing on supported scaffolds as required by §:1926.451(c)(1)(ii). In each of those illustrations, there are identical captions that read, "First tie closest frame header or bearer above 4 times the minimum base dimension."
[Emphasis added.]
The captions appear to conflict with the language in §:1926.451(c)(1)(ii) that provides for first tie installation "at the closest horizontal member to the 4:1 height." [Emphasis added.] Do the captions in the Non-mandatory Appendix override the requirement in §:1926.451(c)(1)(ii)?

Answer: No; the language in §:1926.451(c)(1)(ii) is the legal requirement. This is reflected in the rule's preamble, in which the Agency discusses the issue of whether to require tie-off at the closest horizontal member to the 4:1 height or at the closest point above the 4:1 height. A commenter had suggested that the standard requires tie-in at the closest point above the 4:1 height. OSHA's decision to reject that suggestion was explained in the Preamble's discussion of §:1926.451(c)(1)(ii) in Volume 61 of the Federal Register at page 46042:
OSHA does not agree with the SIA suggestion that guys, ties, and braces be installed at the closest horizontal member above the 4 to 1 base to height ratio, and has revised the language of this provision to reflect the Agency's finding that these components be installed at the closest horizontal member to the 4:1 height, whether above or below, to maximize stability. [Emphasis added.]
We appreciate your pointing out that the captions in the Non-mandatory Appendix are in error. We will be making a technical correction to the Non-mandatory Appendix so that it reflects the language in §:1926.451(c)(1)(ii).

If you need 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 When we originally received these questions from you in April 2003, it was unclear to us if you were requesting a response to each or if they were submitted only to call our attention to these issues in the event that OSHA were to do further rulemaking on the standard. We attempted to resolve that with you, but we were unable to obtain a response; consequently, our office closed the file. After your communications with my staff on January 13, 2005, we understand now that you are requesting a response to each question. We apologize for the misunderstanding and resulting delay in providing this response. [ back to text ]

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