A Perfect Scaffold

By David H. Glabe, P.E. / June 30, 2006

Is there such a thing?  A friend asked me about it the other day; he wondered if I had ever written about a “perfect scaffold.”  Well, I don’t ever recall specifically writing about a perfect scaffold.  I know I have written about safety aspects of scaffolds.  I have written about the components that are part of a perfect scaffold.  I have written about the strength, the stability, the safety of a scaffold but I don’t recall ever having written or described a perfect scaffold.

So what constitutes a perfect scaffold?  It is a scaffold that is constructed so that it can be used by workers without injurious incident.  It is a scaffold that won’t kill the guy that is on it.  It’s a scaffold that has access to the platform and the platform provides access to all work areas.  It is a scaffold that is stable and designed to carry the intended load.  It is a scaffold that allows the worker to go home to his/her family after the workshift.  It is a scaffold that complies with all the applicable standards.  Specifically, the perfect scaffold will include the following:

Fall Protection:  On a supported scaffold, a complete guardrail system, including top and mid rails, will be installed around the perimeter of all platforms except along the edge that is within 14 inches of the work surface (18 inches for stucco/plastering applications).  Alternatively, a personal fall arrest system with conveniently available anchors will be used.  Fall protection height will be determined by the competent person.  In no case will that height exceed 10 feet.  For suspended scaffolds, both a guardrail system and personal fall protection is required on single and two point scaffolds.  For multipoint suspended scaffolds a guardrail system is required although personal fall protection may also be required, as determined by the competent person.

Access:  All scaffold platforms require access whenever there is more than a 24 inch break in elevation.  While there are numerous access choices, typically ladders, stairs, access frames, or direct access are used.  The first step cannot be more than 24 inches.  If you choose to jump out the window onto the scaffold, make sure you are within 14 inches horizontally and 24 inches vertically of the platform.

Falling Object Protection:  All platforms need falling object protection if there is exposure to employees working below.  The easiest solution is to not have employees working above each other.  If that is not possible, screens, debris nets, catch platforms, toeboards or canopies are required.

Electrocution:  It is unhealthy and therefore unwise to come into contact with energized electrical wires unless of course you want to become energized.  As a rule, stay at least three feet away from 300 volt power lines and ten feet away from 50,000 volt lines.  Above 50,000 volts, really stay away.  Consult the standards for the specific distances for specific voltages.

Foundation:  All scaffolds need a foundation, including suspended scaffolds.  For suspended scaffolds, make sure the rigging is properly sized for the intended load.  All components must be mechanically fastened so they act as one unit and you don’t lose critical pieces, such as the counterweights.  Make sure all safety devices are attached, particularly the tiebacks, to proper anchors.  For supported scaffolds, make sure that all scaffolds legs have base plates, no matter who is using the scaffold and no matter whether you are on concrete or not.  Sills may be required.  The qualified person will determine the size of the sill, based on the leg load and the capacity of the supporting soil/surface.

Stability:  All supported scaffolds should be constructed so they don’t rock and roll.  This is done through the proper use of bracing, including cross, diagonal, straight, or combination therefore, and ties, to the existing structure.  If your scaffolds rocks, something is wrong.  For suspended scaffolds, you may be rocking and a rollin’ but it better be controlled!

Strength:  In spite of the opinion of some scaffolders, all scaffolds must be designed by a qualified person, an individual who knows the capacity of the scaffold being designed and the intended use of the scaffold.  While bracing may keep a scaffold from falling over, an overloaded scaffold will ultimately fail and fall down.  This is not good for the occupants of the scaffold.  Besides, it really messes up the scaffold.

There you have it, the perfect scaffold.  It’s so easy to describe, but it seems so difficult to construct.  Maybe it’s because nobody is complying with US Federal OSHA Construction Industry Standards 29 CFR 1926.451(a)(6), 29 CFR 1926.451(f)(7)  and 29 CFR 1926.454, subsections a, b, and c.  Look them up; see if you agree with me.

Tags: Fall Protection Scaffolding Scaffolding Platforms falling object protection OSHA Standards & Regulations Resources scaffold foundation scaffold platform access scaffold stability

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David H. Glabe, P.E.

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