OSHA does not set a single wind speed that forces every roofing crew off the roof. The agency’s guidance treats sustained winds above 40 mph as “high wind” at elevation, dropping to 30 mph when workers are handling materials, and leaves it to the employer to stop work sooner when conditions warrant. That is the short version of OSHA wind speed limits for roofing: 40 and 30 mph are the reference points, but the legal duty to halt work can kick in well below them.
Where the 40 and 30 mph Numbers Come From
The thresholds come from 29 CFR 1926.968, which defines “high wind” as wind strong enough to blow a worker off an elevated surface, cause someone handling materials to lose control, or create other uncontrolled hazards. A note attached to that definition says OSHA “normally considers” winds above 40 mph to meet those criteria, or 30 mph when materials are being handled, unless the employer takes precautions against the wind’s effects.1Occupational Safety and Health Administration. 29 CFR 1926.968 – Definitions
One catch: Section 1926.968 sits inside Subpart V, which technically covers electric power transmission and distribution. There is no identical numbered threshold written into the general roofing standards. OSHA and safety professionals nonetheless apply the 40/30 mph benchmarks as broadly applicable guidance for elevated construction work, and inspectors reference them when judging whether a roofing employer ignored a hazardous condition. Treat those numbers as a floor rather than a ceiling. The General Duty Clause can still be invoked at lower speeds when the danger is obvious.
Lower Thresholds for Specific Roofing Activities
Some activities carry stricter wind limits than the general 40 mph benchmark, and roofing crews using cranes or hoists need to know them before the first lift.
When a crane hoists a personnel platform, 29 CFR 1926.1431 requires a qualified person to evaluate safety any time wind speed, sustained or gusting, exceeds 20 mph at the platform. If that person finds conditions unsafe, the lift cannot begin, and any lift already in progress must be terminated immediately.2Occupational Safety and Health Administration. 29 CFR 1926.1431 – Hoisting Personnel
Tower cranes fall under 29 CFR 1926.1435, which requires that wind not exceed the manufacturer’s recommended speed. If the manufacturer doesn’t specify one, a qualified person must determine the maximum safe wind speed.3Occupational Safety and Health Administration. 29 CFR 1926.1435 – Tower Cranes Manufacturer limits are enforceable through OSHA, not just warranty language.
The 30 mph material-handling threshold from 1926.968 exists for a reason. A worker gripping a large sheet of plywood or a metal roofing panel becomes a sail, and the wind can pull them off balance or toward an edge. Loose materials themselves turn into projectiles well below 40 mph on an unobstructed roof surface, so employers should secure shingles, sheet metal, insulation boards, and tools whenever work pauses or winds pick up.1Occupational Safety and Health Administration. 29 CFR 1926.968 – Definitions
How Wind Weakens the Fall Protection You’re Relying On
The 40 mph number assumes fall protection systems are functioning as designed. Wind can undermine every one of them.
Guardrails
Guardrails must withstand at least 200 pounds of force applied downward or outward near the top edge.4Occupational Safety and Health Administration. 29 CFR 1926.502 – Fall Protection Systems Criteria and Practices That figure assumes static force from a person leaning or falling against the rail. Sustained wind adds a dynamic load the system was not necessarily designed for, especially when tarps or sheeting are lashed to the guardrail and act as sails. Either reinforce the system or strip off anything that catches air.
Warning Lines
Warning lines on low-slope roofs must sit at least 6 feet from the edge (10 feet perpendicular to mechanical equipment), stand 34 to 39 inches above the walking surface, be flagged every 6 feet, and have a minimum tensile strength of 500 pounds. Stanchions must resist at least 16 pounds of horizontal force without tipping.5eCFR. 29 CFR 1926.502 – Fall Protection Systems Criteria and Practices
Sixteen pounds of horizontal resistance sounds adequate in calm conditions, but sustained wind can generate far more lateral pressure when line and flags catch air. If stanchions tip or the line sags below 34 inches, the controlled-access zone is compromised and workers may drift toward the edge without realizing it. Someone has to physically check the warning line during windy shifts.
Personal Fall Arrest Systems
Harnesses, lanyards, and anchors still function in wind, but wind changes fall dynamics. A gust can knock a worker off balance in an unexpected direction and trigger a pendulum swing into the building face, a parapet, or equipment. Site plans should identify swing hazards and position anchor points to minimize lateral travel, with prevailing wind direction as a planning factor.
Scaffolds
Scaffolds have their own rule. Under 29 CFR 1926.451(f)(12), all work on or from scaffolds is prohibited during storms or high winds unless a competent person has determined it is safe and workers are protected by a personal fall arrest system or wind screens. If wind screens are used, the scaffold itself must be secured against the anticipated wind forces those screens will impose.6eCFR. 29 CFR 1926.451 – General Requirements for Scaffolds Wind screens protect workers from gusts but turn the scaffold into something closer to a billboard. If the structure and tie-ins aren’t rated for that added load, the screen creates a worse hazard than the one it was meant to solve.
Eye Protection
Wind-driven debris is its own hazard. Under 29 CFR 1926.102, employers must provide eye protection whenever workers face flying particles, and that protection must include side shields when objects may approach from the side.7Occupational Safety and Health Administration. 29 CFR 1926.102 – Eye and Face Protection Standard safety glasses without side shields aren’t enough on a windy roof. A worker who flinches or grabs at their face near an edge is in a far worse position than one who can see.
The General Duty Clause: Why 40 mph Isn’t a Free Pass
Section 5(a)(1) of the OSH Act, the General Duty Clause, requires every employer to provide a workplace “free from recognized hazards that are causing or are likely to cause death or serious physical harm.”8Occupational Safety and Health Administration. Occupational Safety and Health Act of 1970 – Section 5 Duties This is the legal backstop that makes wind enforceable even without a specific numerical standard for roofing.
An employer can be cited for sending roofers onto an elevated surface in dangerous wind even when the wind is below 40 mph. A 25 mph sustained wind on a four-story steep-slope roof, with workers handling large panels, can qualify as a recognized hazard likely to cause serious harm. The question isn’t whether wind speed hit a magic number. It’s whether a reasonable employer in the same industry would have recognized the danger and stopped work.
A site-specific wind plan is the practical answer. Build it before work begins and include:
- Continuous weather monitoring using an on-site anemometer or a reliable forecast service.
- Pre-set wind speed thresholds for pausing different activities. Material handling might stop at 25 mph while other tasks continue to 35 mph.
- Clear authority for a competent person on site to halt work without waiting for management approval.
- Written documentation of those decisions, which protects the company if an incident occurs and OSHA investigates.
Penalties for Wind-Related Violations
An employer cited for a serious violation, including failure to protect workers from wind hazards, faces a penalty of up to $16,550 per violation under current OSHA enforcement. A willful or repeated violation can reach $165,514 per violation.9Occupational Safety and Health Administration. OSHA Penalties These figures are adjusted annually for inflation.
“Per violation” is where the numbers get serious. If an employer sends a crew of eight onto a windy roof without adequate fall protection, that can be treated as eight separate violations rather than one. A single bad call on a windy day can generate six-figure liability before anyone gets hurt. If a worker is killed, the willful violation ceiling applies, along with potential criminal referral for repeated or egregious disregard of safety standards. The math on shutting down for a few hours of high wind is never close.