In December of 1996, OSHA’s new scaffold standards took
effect. Still, many Construction Standard violations occur
through the improper use of scaffolding. Common violations
include inadequate bracing, no guardrails, unsafe access,
and no pins in scaffolding to prevent uplifting.
General Safety Guidelines
No scaffold shall be erected, moved, dismantled or
altered except under the supervision of competent persons. A
competent person is defined as one who is capable of
identifying existing and predictable hazards in the
surroundings or working conditions, and who has the
authorization to take prompt corrective action to eliminate
Safe Usage of Non-mobile Welded Frame Scaffolding
- The frame scaffold must be capable of supporting four
times the maximum intended load.
- Using a horizontal frame separation distance of seven
feet, the maximum plank extension over the end support
shall be no more than 12 inches if guardrails are not used
to block access to the area.
- On a 10-section wide frame scaffold, the overlap for
each plank on top of each other must be 12 inches.
- A scaffold five feet wide, 35 feet in length and 30 feet
high with frame spacing of seven feet must have horizontal
securement every 20 feet and vertical tie-in every 20
- A frame scaffold, three sections high, using a
cantilevered outrigger platform, shall use ties, guys,
braces, outriggers or scaffold manufacturer’s stabilizer
legs or equivalent.
- Guardrails are required on welded frame scaffolds that
are 10 feet high or more.
- Top rail height shall be at least 36 inches to a
maximum of 45 inches.
- Top rail strength must be at least 200 pounds for
welded frame scaffolds.
- Midrail strength on a welded frame scaffold must be at
least 150 pounds.
- Scaffold legs must bear on base plates and these shall
rest on either firm foundation or mudsills.
- The space between the scaffold planks must be no more
than one inch.
- The maximum distance permitted between a plank and a
frame upright is nine inches.
- An uncleated scaffold plank must extend over the end
support a minimum of six inches.
Scaffolding Cross Bracing and Pins
- Cross bracing is acceptable in place of midrails when
the "X" is between 20 and 30 inches above the
- Cross bracing is acceptable in place of a top rail when
the "X" is between 30 and 48 inches above the
- The purpose of using pins to lock a scaffold vertically
together is to prevent uplift. This can occur with a rough
terrain forklift grabbing scaffold. Wind, climbing a
scaffold or the use of a hoist can also cause it to lift
The maximum intended load of a 10-inch wide, two-inch
nominal thickness wood scaffold plank platform with the
scaffold frames seven feet apart horizontally is
approximately 175 pounds.
- Scaffold platforms above one section high must be
provided with safe access.
- When hook-on-ladders are used, they must be provided
with a rest platform every 35 feet.
- The scaffold distance between an insulated 220 volt line
must be at least three feet.
- Work shall not be permitted during high winds. High
winds are classified by the National Weather Service as 30
mph gusts or higher. Ultimately, the decision is to be
made by the competent person.
DISCLAIMER: These recommendations were developed using
generally accepted safety standards. Compliance with these
recommendations is not a guarantee that you will be in
conformance with any building code, federal, state or local
regulation regarding safety or fire. Compliance with these
recommendations does not ensure the absolute safety of your
occupation or place of business. It is the property
owner’s duty to warn any tenants or occupants of the
property of any safety hazards that may exist.