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Standard Interpretations - Table of Contents
• Standard Number: 1926.501(b)(1); 1926.501(b)(13); 1926.502(d); 1926.502(f)(2); 1926.502(k)

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

December 17, 2003

Regional Administrator

Directorate of Construction

SUBJECT: Clarification of several residential construction and fall protection issues

This is in response to your February 27, 2002 memo and subsequent communications asking for clarification of several residential and fall protection issues regarding the construction of residences and apartment buildings.

Based on your memo and discussions we have had with your office, we have paraphrased your questions as follows:

Question (1): A house or townhouse is constructed as follows: the exterior walls are made of poured-in-place concrete or concrete block; the second floors are made of poured-in-place or pre-cast concrete; the interior walls are framed with metal and/or wood studs, and the roof structure is made of wooden trusses. Do such structures fall within the scope of STD 3-0.1A? If not, [I]s fall protection covered by §1926.501(b)(13)?

Answer: The definition of "residential construction" in STD 3-0.1A was designed specifically for defining the scope of that directive. STD 3-0.1A addresses a subset of residential construction - i.e., stick-built residential construction. The acknowledgement of the infeasibility of conventional fall protection and the specific substitute actions contained in STD 3-0.1A were based on specific feasibility problems associated with residences constructed of wood framing. Since the construction of residences made with the materials and techniques you describe are different, the construction activities described in your memo do not fall under STD 3-0.1A.

While [T]he construction you ask about is not within STD 3-0.1A's scope, it is part of the broader concept of "residential construction" as that term is used in §1926.501(b)(13). Employers who believe that conventional fall protection is infeasible in the construction of a house or townhouse that is beyond STD 3-0.1A's scope may still use alternative procedures if they meet the standards' requirements. Specifically, employers engaged in such construction may use the procedures outlined in §1926.501(b)(13) for making a showing if infeasibility of conventional fall protection. Appropriate alternative fall protection measures may then be used if the employer meets the requirements of §1926.502(k), which includes implementing a written, site-specific fall protection plan.

Question (2): Four "Groups" of construction activities are listed in STD 3-0.1A. For construction covered by STD 3-0.1A, are the alternative fall protection methods described in that directive limited to those four Groups?

Answer: Yes. STD 3-0.1A alternative procedures are available only to activities that meet a three-prong test: (1) The activities are done on a structure that falls within STD 3-0.1A's definition of "residential construction;" (2) They fall within one of the four activity Groups listed in the directive; and (3) They fit under the additional restrictions found in the Groups themselves. Group 4, for instance, excludes roofing at slopes over 8 in 12.

Question (3): If the construction activity in question is considered residential construction, but does not fall within the scope of STD 3-0.1A, does §1926.501(b)(13) apply?

Answer: Yes.

Question (4): If the roof of an apartment is constructed of wood trusses, but the remainder of the structure falls outside the scope of STD 3-0.1A, could the construction of the wood truss roof be within the scope of STD 3-0.1A?

Answer: No. In general, application of STD 3-0.1A depends on whether the house or apartment is being constructed using typical single-family or townhouse stick-built materials and methods, not whether one aspect of its structure (such as the roof) meets the test. Normally, an entire project would be in or out under this test. The one exception is where an adjoining structure, such as an entranceway to a mall, meets the STD 3-0.1A criteria. In that instance the alternative measures in the directive can be applied to the Group activities for construction of the entranceway.

Question (5): Roofers are working a on a low-slope roof on a non-residential structure that is greater than 50 feet in width. The unprotected sides and edges are protected by a combination of warning lines and safety monitors. Under §1926.501(b)(10) (roofing work on low-slope roofs), is it acceptable to have the warning lines consist of lines painted on the roof?

Answer: No. One of the fall protection options that may be used to comply with §1926.501(b)(10) is a "combination of...warning line system and safety monitoring system." Section 1926.502 (f)(2) specifies criteria for warning lines. Under that provision, the lines must:

...consist of ropes, wires, or chains, and supporting stanchions erected as follows...

Therefore, for work covered by §1926.501(b)(10), lines painted on a roof would not meet the requirements for warning lines.

Question (6): Work is being done that is within the scope of STD 3-0.1A. However, the procedures in STD 3-0.1A have not been implemented, nor has the employer implemented a fall protection plan to comply with §1926.502(k) (fall protection plan criteria). Is the applicable fall protection requirement that should be cited §1926.501(b)(13)?

Answer: Yes.

[This document was edited on 12/5/12 to strike information that no longer reflects current OSHA policy referencing STD 3-0.1A.]

Question (7): Is the strength of the type of wood used in a wood truss the sole determining factor in whether the fall protection system anchorage strength requirements in §1926.502(d)(15) are met?

Answer: No. The question really is whether an anchorage can be attached to the roof structure in a way that will result in the entire anchorage being able to meet subpart M's requirements. A typical residential roof truss, by itself, with no blocking/bracing and no roof sheathing in place, would probably be insufficient to meet the anchorage requirements. However, once a roof is structurally complete, the roof decking ties the trusses together. The forces exerted on an attached anchor are then borne not just by a single truss, but by the truss plus the other roof components to which it is attached. Also, additional blocking/bracing can be added to further reinforce the area of the roof where the anchor is attached. Remember too that the anchorage requirements are either 5,000 pounds or a safety factor of 2:11. In many instances the safety factor of 2:1 can be met at significantly below 5,000 pounds.

Also, fall protection is not limited to fall arrest systems. Fall restraint systems impose little force on anchors, and can be deployed on a roof using manually adjusted tethers. Also, there are a number of roof guardrail systems now on the market to protect against falls to the eave ends (and some to the gable ends as well) of the roof. Some of these attach to the walls so as not to interfere with the roofing installation.

1 Under §1926.502 (d)(15), where a safety factor of 2:1 is used, the anchorage must be designed, installed and used under the supervision of a qualified person as part of a complete fall arrest system that maintains a safety factor of at least two. [ back to text ]

Standard Interpretations - Table of Contents

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