Wet floor sign

In many cases, the ability to document correct maintenance procedures and traction levels can be the difference between being named in litigation or not. This begs the question, “How can business owners, facility cleaning managers and custodial contractors accurately test the floors under their care for available traction?”

Walkway audits can be used to document the available traction of flooring surfaces and protect those tasked with caring for them. By determining both the static coefficient of friction (SCOF) and dynamic coefficient of friction (DCOF), certified walkway auditors can determine whether flooring surfaces are in compliance with national standards.

There is some debate in the flooring industry that the measurement of the SCOF is not valid. Many equate the modern SCOF method of measurement to the antiquated ASTM C1028 ceramic tile testing standard. This, however, is like comparing a Model T to an F-35 fighter jet. Modern tribometers are computerized devices used to test the COF. They take the effects of “stiction” — static friction that prevents movement — into account, which is something the C1028 test method could never do. If not accounted for, stiction may cause artificially high SCOF measurements. Therefore, accurate SCOF measurements are commonplace with the advanced computerized devices of today.

Other fallacies about the measurement of SCOF include the notion that “no one slips while they are standing still,” or “people are already in motion and are trying to stop slipping instead of trying to start slipping.” These myths presuppose the object or person is not in motion. SCOF is the measurement of the “potential for slip” of a walkway surface.

During normal human ambulation, when the heel strikes the walkway surface and the walkway has sufficient available traction, the stride will continue. If, at this heel strike moment, the floor surface does not have sufficient available traction, a slip will begin. This “static moment” when the heel strike occurs is the component being measured when the SCOF readings are taken.

While this “static moment” is extremely short, this exact period of time is why the measurement of SCOF is so important. Walkways with deficient or low SCOF create a higher risk of someone beginning the slipping process. Obviously, people are not trying to start slipping, but because the SCOF of the shoe and walkway interface is too low, the slip can begin.

Almost everyone has experienced the small “oops, I slipped” feeling, as well as the relief that it was only a small slip. Some have experienced a catastrophic slip, finding themselves sitting on their backside or down on one knee. These are the slips and falls that can cause serious injuries and even claim some lives.

All slips involve characteristics of both SCOF and DCOF. The uncontrolled sliding of the heel across a flooring surface is a characteristic of low DCOF. The slide of DCOF comes after the heel has overcome the available traction of SCOF.

DCOF is the measurement of the force required to keep an object moving when in contact with another surface. This process measures the “potential for slide” across a walkway surface. Once the SCOF threshold has been exceeded, the slide portion of a slip and fall begins. The higher the measurement of DCOF, the lower the potential for a catastrophic slip and fall.

next page of this article:
Understanding Floor Testing Standards, Safety Requirements