Scaffolding: How to Build, Forms, and More
What goes up mustn't come down accidentally.
Synopsis: This article describes the many forms of scaffolding, from pipe staging and roof brackets to pump and ladder jacks, and how they should be used. A sidebar discusses OSHA, the government’s job-safety program.
There are few subjects in construction with as little glamour or as much importance as scaffolding. Often erected in a hurry, abused by those who literally depend on it and torn down without ceremony, a scaffold is the ugly chrysalis whose removal reveals a butterfly.
Hard-earned knowledge of construction rigging is one of my most important resources as a builder. The ability to erect a safe, effective work platform is a skill that can be acquired only through thoughtful experimentation with the different systems available. There are nearly as many types of scaffolding as there are different types of jobs, and the ideal setup for a given situation is often a combination of several. As a result, I sometimes enjoy rigging a job more than I enjoy the job itself.
A word of caution is in order before I begin. The Occupational Safety and Health Administration (OSHA) has identified scaffolding as a leading cause of accidents in construction. OSHA’s standards for the construction industry include 17 pages on scaffolding. While I mention some of these regulations in my discussion, it would be impossible, in this space, for me to list them all. Therefore, I recommend that everyone read the OSHA standards before setting up or using any type of scaffold. For more on OSHA and for information on how to get a copy of their Construction Industry Standards.
The basic scaffold consists of two parts: a pair of supports and a horizontal platform. Wood planking is the most common platform material. The standard scaffold plank available at lumberyards is a full 2-in. by 9-in. scaffold-grade rough sawn spruce plank. The rough texture provides a non-skid surface, and the extra thickness makes a more substantial platform than ordinary 2x dimension lumber. Thirteen feet is the standard length, providing for a 12-ft. span with 6 in. of overlap at each support. Some regulations insist on even shorter spans, dropping down to a 10-ft. maximum.
All planks should be inspected carefully for defects. Small knots and some checking on the ends of planks is okay. But long spike knots and short grain are dangerous because they break the continuity of the wood fibers. Large enclosed knots and splits should also be eyed with suspicion. All of these defects are aggravated by water and dry rot, so planks should be stickered when not in use. Periodic application of wood preservative is also a good idea. If planks become the least bit punky, get rid of them.
Twist should also be considered a serious defect in scaffold planks. It can make the plank roll as you step from side to side. If this sudden shift is extreme, you can lose your balance and take a fall.
For more illustrations and details, click the View PDF button below: