Manually Propelled Mobile Scaffold Safety

Scaffold & Elevated Work

Manually Propelled
Mobile Scaffold Safety

OSHA 1926.452(w) · NYC BC §3314 · Never Move While Occupied · Outriggers Required Above 2:1

TT-013 · Plumb AI Safety · NYC Construction

Rolling (mobile) scaffolds are everywhere on NYC interior jobs — drywalling, MEP rough-in, ceiling work. Their convenience is also their danger: they can be rolled while occupied, they tip easily on uneven floors, and workers routinely ignore wheel locks and outrigger requirements. A few simple rules prevent most mobile scaffold injuries.

Height-to-Base Ratio — The Critical Rule

A mobile scaffold must have a minimum base dimension of one-third its platform height on all sides
For interior mobile scaffolds on smooth floors: maximum 2:1 height-to-minimum-base-width ratio
When the ratio exceeds 2:1: outrigger frames or stabilizers required on all four sides — no exceptions
Example: a 12-foot-high scaffold on a 5-foot base (2.4:1) requires outriggers on NYC sites

The Rules That Get Ignored — Don't Be That Worker

Never move the scaffold while occupied — even "just a few inches." Workers must dismount before repositioning
Lock all wheels before ascending — all four wheels, every time, not just the ones you can easily reach
Do not use the scaffold as a ladder — access through the interior ladder frames only
Do not exceed the rated platform capacity — tool weight adds up fast on small platforms
Never move the scaffold over uneven floors, ramps, or thresholds — disassemble and reassemble on the other side

Floor Condition on NYC Sites

Concrete floors with patch areas, construction debris, or wet spots create tip hazards for mobile scaffolds — inspect the path before moving
Plywood subfloor: verify it can support the scaffold load at the specific bay spans — ask the super before positioning
Never position a mobile scaffold over floor openings — the wheel could punch through a plywood cover

Discussion Questions

Your mobile scaffold is 10 feet high with a 4-foot base. Do you need outriggers? Walk through the math.
Your foreman asks you to "just roll it over a foot" while you're standing on the platform. What do you say?
After lunch you return to find someone has moved your scaffold and the wheels aren't locked. Before you climb, what do you do?
The path to move your scaffold has a plywood floor cover over a beam pocket. What should you do?

Sign-Off

Project Address

Date

Time

Foreman / Supervisor

SSM / SSC Name & License No.

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