United States
Hong KongScaffold capacity and platform rules
A scaffold must support four times the maximum intended load, and suspension ropes six times. Platforms are at least 18 inches wide, planks overhang between 6 and 12 inches, and gaps to uprights are capped at 14 inches.
Subpart L, and a category with more specific dimensions than almost anything else in the standards.
The capacity multiples
Four times the maximum intended load for the scaffold itself, at 29 CFR 1926.451(a)(1).
Six times for suspension ropes, at 1926.451(a)(4). Higher because a rope failure on a suspended scaffold is unsurvivable in a way a supported scaffold failure may not be.
Four times for scaffolds and ladders. Six times for suspension ropes. Twice for hole covers. Three different multiples in the same body of standards, and questions offer all three.
Platform dimensions
| Requirement | Figure |
|---|---|
| Minimum platform width | 18 inches |
| Minimum plank overhang | 6 inches |
| Maximum plank overhang | 12 inches, or cleated |
| Maximum gap to uprights | 14 inches |
The overhang pair is the one to hold together. Less than 6 inches and the plank can slip off its support; more than 12 and it becomes a diving board unless cleated.
Height to base ratio
A supported scaffold more than four times its minimum base dimension in height must be restrained from tipping, at 1926.451(c)(1).
Four again, doing different work. Read the question carefully to see which four it wants.
Power line clearance
Ten feet minimum from energized lines up to 300 volts under 1926.451(f)(6), with greater distances above that.
Who erects it
Under the supervision of a competent person, and inspected by one before each work shift. Authority rather than expertise, which is why it is competent rather than qualified.
Common questions
What load must a scaffold support?
Four times the maximum intended load, and six times for suspension ropes.
What is the minimum scaffold platform width?
18 inches.
How far may a plank overhang?
At least 6 inches and no more than 12, unless cleated.
When must a supported scaffold be restrained?
When it exceeds four times its minimum base dimension in height.
Who inspects a scaffold?
A competent person, before each work shift.