How to install frame scaffolding
When frame scaffolding (also called pipe staging or tubular scaffolding) is in good condition and erected properly, it provides a stable elevated work platform at virtually any height with enough room so workers can move freely.
But if mistakes are made assembling it, or individual components are abused or otherwise damaged, serious accidents and even deaths can occur.
According to the Occupational Safety and Health Administration (OSHA), 25 percent of scaffolding-related fatalities involve frame scaffolding (as opposed to pump jacks, ladder jacks, roof brackets and various other types of lifts). The top five hazards related to frame scaffolding are falls, collapse, unsafe access and falling objects.
When assembling or using frame scaffolding follow these critical steps.
Get a safe start
Always start with a stable, solid base. Remove mud and debris from the setup area and level the ground where the staging legs will be placed.
A good scaffolding safety tip is to always use screw jacks or base plates proprietary to the system you are using. Don’t mix and match staging components from manufacturers.
While you should always use wood blocks for mudsills under the base plates or screw jacks, never use stacks of wood or concrete under the legs to level them. Screw jacks should be the only leveling system used. Nail or screw the base plates to the mudsills.
The first level of frame scaffolding
Use a level and a string line to set all sections of the first level to assure they’re level and square.
Make sure all cross bracing fits and locks onto each post in every section. Never try to “rig” braces that don’t fit properly, with tie-wire, for example.
Successive levels of frames should fit properly and lock securely onto the coupling pins of the lower level.
As the scaffold height increases, codes require the scaffolding to be secured to the building structure at a height that is four times the narrowest base dimension (so for a 5-foot-wide frame, the scaffolding needs to be secured at 20 feet high, and every 20 feet thereafter).
These ties should be repeated at horizontal intervals no greater than 30 feet, starting from one end of the staging.
Never use unmatched sets of staging that don’t fit together easily and securely. Never omit the toggle pins that secure both ends of the couplers between frames. They provide an additional means of locking to prevent wind uplift, which can cause stacked frame sections to separate vertically.
Frame scaffolding planking
Engineered lumber and aluminum planks are safer and more durable, but are more expensive.
If you’re trying to save money, use plank-grade lumber, but never use framing lumber, which may have knots that can become a dangerous weak point.
Plan ahead for the weight the planks will have to carry, including tools and materials – not just the weight of the crew.
Kick-boards, also called toe-boards, should be a minimum of 4 inches high to prevent tools and materials from falling or being accidentally kicked off the platform.
Every working level must be fully planked across the work platform with no gaps wider than 1 inch.
Typically, platforms higher than 10 feet require two guardrails placed about 19 and 42 inches above the work platform, but always check local codes for exact requirements in your area.
If you don’t have manufactured guardrails, use 2×4 lumber tied with #18 tie-wires. Never use cross-braces as guard rails.
Always enclose open ends with end rails that span the entire work platform and run all the way to the side of the building.
Getting up there
Do not use the scaffold frames as a means of climbing up to work platforms. They’re designed for support only, not access.
Ladders should be properly supported and secured to the staging, and should extend at least 3 feet above the upper landing level.
Prefabricated staging stairs are expensive, but are definitely the best choice when working on projects requiring multilevel scaffolding. Always install hand railings on both sides of staging stairs.
These frame scaffolding guidelines represent the basic rules that all members of the work crew should know. There are many other safety rules that should be followed as well.
Make sure everyone working on the scaffolding is properly trained to set it up and inspect all components for damage.
Safety training and advice for proper erection of frame scaffolding is easily available. The Scaffold Industry Association (www.scaffold.org) offers a number of training courses through its local members, and most scaffolding suppliers have an engineer on staff or will contact the manufacturer for you if you have questions in the field.
But if you are going to be using frame scaffolding (or any other type of scaffolding) on any of your jobs, first read “A Guide to Scaffold Use in the Construction Industry/OSHA 3150,” which you can download free at www.osha.gov.