Two contractors operating as a single employer at a worksite in Massachusetts, had a serious accident and subsequent citation from OSHA, when at least two crew members of the company fell from a wooden plank on a scaffold. OSHA investigated and found that the wooden plank they were standing on was stamped “NOT FOR STAGING”. The company was fined $173,500 in OSHA citations.
No Substitute for Scaffold Graded Planks
No contractor should be using ordinary wood as scaffold planks. Scaffold planks are not planed, leaving them thicker, and less prone to bending. When you walk on a plank, if it bends too much it can shift off the frame part, causing the plank to give way or break. This could cause not only the employee(s) on that level to fall from (sometimes) an extreme height, but anyone working below can also be injured as the falling planks and work material fall and cause a chain reaction. If using a 12′ foot plank, with 1′ overhang on each side, the planks across the 10-foot span cannot deflect (bend down) more than 1/60th of the length (10′ =120″. 120″/60 =2″) or 2″ in the middle! That means you need a graded un-planed plank rated as a scaffold plank. You can tell from the grade stamp if it is approved for use in scaffolding.
Solid Sawn Wood Plank Grading for Scaffolds
When using wood planks, they need to be graded as un-planed planks, and inspected each day for things like cracks in the wood, not positioned with the correct overhang, damage, wood grading that is illegible, etc.
Before the planks are even set up at the worksite, there is a checklist that should be completed at the time of purchase, to ensure that the right type of plank is being bought. That way you can be sure inferior planks do not make it to the worksite and are then confused for appropriate scaffolding material.
Is the plank capable of meeting the one person loading requirement, when the plank is supported on a 10-foot span? ANSI A10.8-2011 5.2.1
Does it bear a grade stamp that is rated as “Scaffold Plank” from a grading agency that has been approved by the American Lumber Standards Committee? ANSI A10.82011 5.2.4
Does the stamp include the manufacturing mill name, and the manufacturing mill number?
Does it comply with the elevated moisture content requirement, so that if it is sold, used, or stored with elevated moisture content it is sized using green or wet use stresses? ANSI A10.8-2011 5.2.8
Does it have an opaque finish on it? Clear finishes are permitted. ANSI A10.8-2011 5.2.12 and OSHA 1926.451(b)(9)
Does the product name on the literature match the product name on the plank?
Does the literature indicate that it is designed so that it does not deflect more than 1/60th of the span under design load? OSHA 1926.451(f)(16), ANSI A10.82011 5.2.2
Can the manufacturer supply a certificate of insurance upon request?
Can the manufacturer supply a certificate of grade upon request?
Can the manufacturer identify all mill sources?
Can the manufacturer respond to field/ technical questions?
This is not an exhaustive list, however it is a good place to start when you are sourcing your planks for scaffolds. It is important that you can reach the manufacturer with questions if need be.
There is no substitute for quality materials when it comes to workplace safety. In the end, it is a lot easier and less expensive to get the right grade planks in the first place.
photo credit: Pixaby/bstad