Words: Kevin O’Shea, Director Of Safety And Training At Hydro-Mobile

We pride ourselves in our ability to solve problems on the job using our ingenuity, adaptability and sometimes just sheer determination to get the job done. This ‘can do’ attitude is part of the American construction culture and as much as it has contributed to job performance over the decades, it has also created huge liability and safety issues for employers and equipment owners over the same period.

An example of this double-edged sword is scaffold attachments.

There are many types of scaffold attachments like debris netting, hoists, and cantilever brackets just to name a few. They all have to be rated with the same minimum factor of safety requirement as the scaffold itself. When fitted, they also cannot reduce the scaffold factor of safety below the minimum level required by OSHA regulations.

The word scaffold can mean a number of things in our industry. To localize the issue and make it more relevant, let’s look at three types of access equipment which can fall under the description of supported scaffold: tube and clamp, mast climbing work platform (MCWP), and scissor lifts (mobile scaffold).

Common types of attachments

Material Hoists

This is common to both Tube and Clamp Scaffold and MCWP’s, and it’s vital to remember the following:

The addition of the hoist WILL affect the structural integrity of the scaffold, so it MUST be designed by the manufacturer or an appropriately-qualified engineer. This means that before you attach it to the scaffold, you should have one of two things. You need to either have a manual from the manufacturer explaining how it should be attached, what the load and configurations are and what restrictions there are OR a set of drawings and instructions from an engineer explaining a similar set of details.

Those personnel who are using the hoist should be trained in the safe use of appropriate rigging equipment (slings, shackles etc.), and should know both how to inspect the rigging equipment and know how to communicate with the forklift or crane operator via industry authorized hand signals.

Trash Chute

There are daily examples of trash chutes attached to scaffolds; they’re a common sight on refurb or demolition jobs. Remember these important points:

Trash Chutes can pick up wind and transfer the load to the scaffold, creating the potential for overload of the scaffold.

Who’s in charge of emptying the dumpster! Trash chutes are often fed into a dumpster and, to reduce pollution, a dumpster cover is used. There are literally hundreds of instances where the dumpster cover has concealed the fact that the dumpster is full, and the trash chute is half full of debris. This can potentially collapse a scaffold. Someone MUST be nominated to inspect the dumpster regularly.


OSHA regulations contain important language about the use of attachments. Here are some really important points to remember if you want to stay in compliance:

1926.451(a)(1): Capacity: each component must support without failure its own weight and 4 times maximum intended load.

If you add an attachment to a scaffold OSHA requires that the attachment has to have minimum 4:1 safety factor. Additionally if the capacity of the attachment is less than that of the scaffold there must be ample conspicuous signage to inform those on the scaffold of the change in capacity, and the capacity change should be covered in formal job-specific training.

An example of a poorly constructed attachment, which does not retain the 4:1 to intended load safety factor.

1926.451(a)(6): Scaffolds must be designed by a qualified person, and must be constructed and loaded in accordance with the design.

It’s extremely unlikely that scaffold users meet OSHA’s definition of ‘qualified’ when it comes to scaffold design. An attachment requires design input from a ‘qualified’ person for it to be fully compliant.

Two mast scaffolds connected by aluminum beams which are neither secured in place nor adequately guarded. There is also a major question mark over the beams’ ability to take sufficient load. 

1926.451(b)(10): Scaffold components from different manufacturers must not be intermixed unless they fit together without force and the user maintains the scaffold’s structural integrity.  The components must not be modified in order to intermix them unless a competent person determines the resulting scaffold is structurally sound.

As with the previous example, the decision as to whether attachments retain the scaffolds’ structural integrity does not generally fall to the user. An engineer or designer will normally be involved in the assessment.

1926.451(f)(1): Scaffolds and scaffold components must not be loaded in excess of their maximum intended loads or rated capacities whichever is less.

When a scaffold attachment is properly designed by a qualified person and installed by a trained, competent person, and the load capability is clearly visible to users who have been trained to understand what the load limitations of the scaffold are, the likelihood of full compliance is high. The photograph here shows two problems.

The upright wooden beam for carrying the cable is exerting a load outside of the platform extremities creating the potential for tipping, and the makeshift weather canopy is effectively adding a significant overload factor on the platform.

1926.451(f)(3): Scaffolds and scaffold components must be inspected for visible defects by the competent person before each work shift AND after any occurrence which could affect a scaffold’s structural integrity.

Attachments fall under this same rule, and whoever is doing the inspection requires to prove that he or she is ‘competent’ to carry it out.

1926.451(f)(7): Scaffolds shall be erected, moved, dismantled, or altered only under the supervision and direction of a competent person qualified in scaffold erection, moving, dismantling or alteration. Such activities shall be performed only by experienced and trained employees selected for such work by the competent person.

Attachments come under the same language as the scaffold itself and it’s vital that erection, dismantle, alteration and removal should be carried out under the auspices of a Competent Person using employees who have documentation to prove both training and experience.

1926.451(f)(14): Makeshift devices, such as but not limited to boxes and barrels, shall not be used on top of scaffold platforms to increase the working level height of employees.

There are many examples of non-compliance here, and almost every job site will contain a few examples. Here are just a few:

The use of ladders, scaffold boards etc to gain further height on a scissor lift is an absolute no.

The picture clearly shows why. There is a potential for the ladders to slip on the platform, no fall protection, and the ladder is detrimentally affecting the stability of the scissor lift.

There is a huge amount of potential liability inherent in the use of attachments. The most common misuse comes when an owner or user decides it would be a great idea to put their banner or sign or debris netting on the scaffold.

The amount of extra load this can exert on the scaffold is extremely significant. Before you decide to put a banner or sign or netting on your scaffold ask yourself these questions:

How much potential load will the banner or sign or netting exert on the scaffold relevant to maximum allowable wind speeds for the scaffold use?

Have the tie backs to the structure been assessed to evaluate their ability to take the extra load, and still retain minimum factor of safety values?

Has someone been nominated to inspect the banner or sign or netting and the scaffold before each shift?

Who is in charge of monitoring the wind speed?

Has all of the above been authorized by either the manufacturer or a qualified person?

Scaffold attachments can be convenient, time-saving and productive but they almost always mean extra load on the scaffold. Attachments should be properly designed into the scaffold, taking into account additional load, compatability, and additional safety and training requirements.

This almost always requires the input of the manufacturer and/or a suitably qualified engineer.