4.3 Scaffolds, ladders, steel erection, lifts and roofs

1 Scaffolds — Subpart L

The trigger is more than 10 feet above a lower level, 1926.451(g)(1), and the system depends on the scaffold type: fall arrest for boatswain's chairs, catenary, float, needle beam and ladder jack scaffolds; both fall arrest and a guardrail for single-point and two-point adjustable suspension scaffolds; a guardrail for walkways within a scaffold; fall arrest or a guardrail for everything else. 1926.451(g)(2) requires fall protection for erectors and dismantlers where a competent person determines it is feasible and does not create a greater hazard.

Guardrails on scaffolds have their own dimensions, and they are not Subpart M's. Under 1926.451(g)(4)(ii), the top edge height of top rails on supported scaffolds manufactured or placed in service after January 1, 2000 shall be between 38 and 45 inches; for earlier scaffolds and for suspension scaffolds the range is 36 to 45 inches. Top rail strength is 100 pounds for single-point and two-point adjustable suspension scaffolds and 200 pounds for all other scaffolds — 1926.451(g)(4)(vii).

The rest of the scaffold rules that keep people from falling are structural: capacity of 4 times the maximum intended load ((a)(1)); platforms fully planked with gaps no more than 1 inch ((b)(1)) and at least 18 inches wide ((b)(2)); front edge within 14 inches of the work face ((b)(3)); base plates and mud sills on level, sound, rigid footings ((c)(2)); restraint from tipping above a 4:1 height-to-base-width ratio ((c)(1)); safe access with crossbraces never used as a means of access ((e)(1)); competent person inspection before each work shift and after any occurrence affecting structural integrity ((f)(3)); erection, moving, dismantling and alteration only under the supervision and direction of a competent person qualified in scaffold erection ((f)(7)); and falling object protection under (h).

2 Ladders and stairways — Subpart X

Ladders, 1926.1053, was the third most cited standard in FY 2025, and it contains no fall arrest requirement for portable ladders at all. It controls setup, condition and behavior instead:

Training is in 1926.1060: a program for each employee using ladders and stairways, covering the nature of the fall hazards, the correct procedures for erecting, maintaining and disassembling the systems, the proper construction, use, placement and care in handling, and the maximum intended load-carrying capacities.

Fixed ladders are the one place where climbing fall protection is mandated, and it is in general industry: 1910.28(b)(9) requires ladders extending more than 24 feet above a lower level to have a personal fall arrest system, a ladder safety system, a cage or a well; ladders installed on or after November 19, 2018 require a personal fall arrest system or a ladder safety system; and on and after November 18, 2036, all fixed ladders must have one of those two.

3 Steel erection — Subpart R

The height is more than 15 feet under 1926.760(a)(1). Connectors are protected from fall hazards of more than two stories or 30 feet, whichever is less, must have completed the connector training required by 1926.761, and above 15 feet must be provided with and use fall protection equipment where it is provided and can be used — 1926.760(b).

A controlled decking zone under 1926.760(c) permits work without conventional protection over 15 and up to 30 feet above a lower level where metal decking is initially being installed, within a defined boundary no more than 90 feet wide and 90 feet deep, with unsecured decking limited to 3,000 square feet, and only employees trained for CDZ work under 1926.761 permitted to enter.

And 1926.760(e) is the paragraph that settles inter-trade arguments: fall protection provided by the steel erector shall remain in the area where steel erection activity has been completed only if the controlling contractor or its authorized representative has directed the steel erector to leave it, has inspected and accepted control and responsibility for it, and has agreed to assure that it meets the applicable criteria before it is used by other trades. Absent that, the steel erector takes it with them and the next trade provides its own.

Training here is by a qualified person — 1926.761(a) — with fall hazard training in (b) and special training programs in (c) for multiple lift rigging, connecting, and controlled decking zone work.

4 Aerial lifts, scissor lifts and cranes

Aerial lifts — 1926.453. Two paragraphs matter more than the rest. (b)(2)(iv): employees shall always stand firmly on the floor of the basket and shall not sit or climb on the edge of the basket or use planks, ladders or other devices for a work position. (b)(2)(v): a body belt shall be worn and a lanyard attached to the boom or basket when working from an aerial lift. OSHA's note explains that the body belt is acceptable here as part of a tethering or restraint system under 1926.502(e) — not as fall arrest. The basket's guardrails are the fall protection; the tether keeps you inside them. The lift's own operating instructions govern which anchor point in the basket may be used.

Scissor lifts. A scissor lift is a mobile scaffold in OSHA's classification, not an aerial lift, and its guardrails are its fall protection. Do not defeat them: no standing on rails, no planks across the rails, no gate propped open. As Chapter 3.2 showed, at typical scissor lift heights a fixed-length shock-absorbing lanyard has nowhere to work — which is another reason the platform, not the harness, is the system.

Cranes and derricks — Subpart CC. 1926.1423 sets its own fall protection rules for employees on crane equipment, and it uses two heights: employees on a walking/working surface with an unprotected side or edge more than 6 feet above a lower level must be protected during ordinary operations, while during assembly and disassembly the trigger is more than 15 feet. The section also addresses horizontal lattice booms, where fall protection is required where the fall distance is 15 feet or more. Read 1926.1423 itself before writing a plan for crane work; it is short and the distinctions matter.

5 Roofing, and residential framing

Roofing stays inside Subpart M, but it is worth collecting in one place because roofing contractors accounted for 100 fatal falls, slips and trips in construction in 2022 and roofs were the primary source in 165 fatal injuries that year.

• Low-slope roof (4 in 12 or less), 1926.501(b)(10): the three systems, or a warning line combined with a guardrail, net, personal fall arrest or safety monitoring system — and a monitor alone only on a roof 50 feet or less in width.
• Steep roof (above 4 in 12), 1926.501(b)(11): guardrails with toeboards, safety nets, or personal fall arrest. No warning lines, no monitors.
• Holes and skylights, 1926.501(b)(4): covers to the 1926.502(i) criteria, guardrails, or fall arrest — and skylights are named in the paragraph.
• Material storage, 1926.502(j)(4): nothing stored within 6 feet of a roof edge unless guardrails are erected.
• Mechanical equipment: 1926.503(a)(2)(v) makes the limitations on mechanical equipment during low-slope roofing a mandatory training topic, and 1926.502(h)(2) prohibits mechanical equipment where safety monitoring is in use.

Residential framing sits under 1926.501(b)(13), with the same three systems and the same narrow route to a 1926.502(k) plan on a site-specific demonstration. What has changed in practice over the past fifteen years is enforcement: the trade-wide alternative-measures approach is gone, and the demonstration has to be about the house in front of you. Engineered temporary anchors, guardrails at floor and roof edges, and prefabrication at ground level are the answers that have replaced it.

6 The one question that resolves all of it

Before you quote a height, ask: which subpart is this work under? Then read that subpart's fall protection section, not Subpart M's.