06/17/2005 - Whether it is permissible to use a concrete block hanging on a coupling pin as a counterweight to prevent a scaffold from tipping.

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Standard Interpretations
06/17/2005 - Whether it is permissible to use a concrete block hanging on a coupling pin as a counterweight to prevent a scaffold from tipping.

Standard Interpretations - Table of Contents

• Standard Number:

1926.451; 1926.451(a); 1926.451(a)(1); 1926.451(a)(12) ; 1926.451(b); 1926.451(b)(5); 1926.451(b)(5)(i); 1926.451(b)(5)(ii); 1926.451(c)(1)(iii)

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.

June 17, 2005

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

Re: Whether it is permissible to use a concrete block hanging on a coupling pin as a counterweight to prevent a scaffold from tipping; §1926.451

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 are responding in a series of separate letters in response; this is the seventh in that series.

We have paraphrased your question regarding the use of a masonry block on a coupling pin as follows:

Question: Scenario: On several occasions I have seen, on a supported scaffold, one or more concrete blocks that have been placed on coupling pins to serve as counterweights for a mason standing on a cantilevered deck located on the other side of the scaffold. In other words, the block is used to prevent a scaffold with an eccentric load from tipping. Is this practice permissible under §1926.451(c)(1)(iii)?

Answer: In Subpart L (Scaffolds), §1926.451(a) of the General requirements provides in part:

(1) 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.
* * *
(12) Scaffolds shall be designed by a qualified person and shall be constructed and loaded in accordance with that design.
* * *

In addition, §1926.451(b) Scaffold platform construction contains the following limitations relative to cantilevered portions of platforms:

* * *
(5)(i) Each end of a platform 10 feet or less in length shall not extend over its support more than 12 inches (30 cm) unless the platform is designed and installed so that the cantilevered portion of the platform is able to support employees and/or materials without tipping, or has guardrails which block employee access to the cantilevered end.
(ii) Each platform greater than 10 feet in length shall not extend over its support more than 18 inches (46 cm), unless it is designed and installed so that the cantilevered portion of the platform is able to support employees without tipping, or has guardrails which block employee access to the cantilevered end.

One of the requirements for scaffolds with eccentric loads is §1926.451(c)(1)(iii):

Ties, guys, braces, or outriggers shall be used to prevent the tipping of supported scaffolds in all circumstances where an eccentric load, such as a cantilevered work platform, is applied or is transmitted to the scaffold. [Emphasis added.]

Thus, in a scenario involving an eccentric load on a cantilevered portion of a platform, the qualified person's design must conform to this criteria. The use of the masonry blocks as what appear to be improvised counterweights indicates that, in the scenario you describe, the scaffold has not been adequately secured against tipping in accordance with §1926.451(c)(1)(iii).

Furthermore, under §1926.451(b)(5), unless designed and installed to support the load without tipping, the cantilevered portion of the platform is prohibited from extending beyond its support more than 12 inches (or 18 inches if the total platform length is more than 10 feet). The use of the blocks in the scenario may indicate that this requirement has also been violated.

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 ]

Standard Interpretations - Table of Contents


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