Supported scaffold load ratings
Supported scaffold is rated by the load its platform is designed to carry. Three classifications cover the range, and the one you choose affects both the design and, at the top end, whether the scaffold can be exempt from a permit at all.
The three ratings
- Light duty, 25 pounds per square foot. Workers with lightweight material such as wood, paint or tools.
- Medium duty, 50 pounds per square foot. Workers with moderate material such as brick, block and pipe.
- Heavy duty, 75 pounds per square foot. Workers with heavy material such as stone.
Why the rating matters for permits
One of the three conditions that keeps a supported scaffold under 40 feet exempt from a permit is that it is not loaded, and not designed to be loaded, above 75 pounds per square foot. A heavy duty rating sits exactly at that boundary.
Rate it for reality
Under-rating to save material is the expensive mistake. The scaffold gets loaded with whatever the job actually requires, and a platform designed for paint does not carry stone. Over-rating is merely wasteful. Rate the scaffold for the heaviest material that will realistically sit on the deck.
Key facts
- Light duty
- 25 psf
- Medium duty
- 50 psf
- Heavy duty
- 75 psf
- Permit exemption ceiling
- 75 psf
Common questions
What rating does typical facade repair need?
Masonry repair with brick and pipe usually calls for medium duty. Stone setting pushes it to heavy duty. Pointing and coating work is often light duty.
Can different levels have different ratings?
The design has to account for how the scaffold is actually used. Where loading varies, the design should reflect the governing condition.