When does OSHA require guardrails on scaffolding?

Short answer. On scaffolds more than 10 feet high, under 29 CFR 1926.451. As prime contractor you are responsible for site safety, including your subcontractors' compliance, and OSHA can cite you directly.

29 CFR 1926.451

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You're the contractor. Pick what you'd do, then see how each choice plays out.

Mike Delgado

Electrician who sometimes cuts corners but charges less

You arrive at a job site to find that Mike Delgado, the electrician you hired, has workers on a 12-foot scaffold with no guardrails and no hard hats. One of them is wearing flip-flops.

Mike shrugs. "We're almost done. It's fine."

Correct
OSHA requires guardrails on scaffolds above 10 feet (29 CFR 1926.451). Hard hats are required on construction sites where there is a danger of head injury. As the prime contractor, YOU are responsible for site safety, including subcontractor compliance. An OSHA inspector finding this would cite YOU, not just Mike. Fines can be $15,000+ per violation.
Wrong
'Hurry up and finish' while knowingly allowing unsafe conditions makes you complicit. If someone falls, you face OSHA fines, a workers comp claim, potential criminal negligence charges, and MHIC action. The cost of stopping work for 30 minutes to install guardrails: $0. The cost of a fall injury: everything.
Wrong
As the prime contractor and general employer on site, you have OSHA obligations regardless of subcontractor relationships. Multi-employer worksite doctrine means OSHA can cite the controlling contractor for hazards affecting any worker on site. Your MHIC license and $50,000 liability insurance don't insulate you from site safety responsibility.

When does OSHA require guardrails on scaffolding?

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