How Do You Know if Polished Concrete is Slippery?
Published September 21 2015
According to the National Floor Safety Institute (NFSI), 55% of slips, trips and falls are caused by a hazardous walkway surface. Because of the high gloss produced by polishing concrete, many end users associate this with other polished surfaces and erroneously assume it is slippery. In some cases they are correct, but not always. Over the past 25 years I have worked in the slip and fall prevention industry and I have yet to find a one-size-fits-all approach between the gloss level of a walkway and its slip resistance. Much of what our society has come to expect regarding the gloss level of a floor and its inherent safety comes by way of marketing. During the 1950’s, consumers were first introduced to high-gloss floor finishes which not only offered the benefit of ease of maintenance but that of the “wet-look” which was associated with the “clean look”. This trend grew through the 1960’s as manufacturers of vinyl floor coverings began to introduce high gloss vinyl no-wax floors and further grew in the 70’s and 80’s with gloss enhancing vinyl floor cleaners. In the end, we as consumers have come to associate a clean floor to that of a shiny floor. Unfortunately, these clean looking high gloss floors are too often perceived to be as slippery as ice.
To counter this perception, manufacturers of floor finishes and polishes have relied upon the ASTM D-2047 (UL-410) standard for determining the slip resistant properties of their products. For decades, this test method divided products into two categories, those whose dry Static Coefficient of Friction (SCOF) was equal to or greater than a 0.5 value and those who SCOF were below the 0.5 value. Products that met the 0.5 or greater value were “Classified” as “Slip Resistant”, while products whose SCOF was below the 0.5 value were simply not classified. For many, this pass-fail approach created the perception that products meeting the 0.5 value were “safe” while those that did not were “un-safe.” This perception is in fact not true and has created the myth that a dry floor that fails to meet the 0.5 threshold is unsafe, rather than it is simply not slip resistant.
Unfortunately, many people erroneously apply the D-2047 standard to floors other than those coated with a commercial floor polish, even those surfaces that cannot be laboratory tested. Because the James Machine is the exclusive test device for the D-2047 and cannot be used outside of a laboratory setting, this makes the application of this standard to surfaces like polished concrete impossible.
Since approximately 80% of all slip and fall claims occur on wet floors, it only seems reasonable to test walkways under wet conditions rather than dry. In December 2009, the NFSI/ANSI B101.1-2009 “Test Method for Measuring Wet SCOF of Common Hard-Surface Floor Materials” was published, establishing the first ever wet test method for walkway surfaces.
Rather than the pass-fail approach established by the ASTM D-2047 method, the ANSI/NFSI B101.1-2009 standard identifies three individual risk categories or “Traction Ranges” to which each range describes the risk potential for a slip-and-fall. Surfaces whose wet SCOF is 0.6 or greater are referred to as “High-Traction.” Walkways whose wet SCOF is below a 0.6 but greater than a value of 0.4 are defined as “Moderate Traction” and walkways which posses a wet SCOF of less than 0.4 are defined as “Low Traction.” High Traction surfaces present the least amount of risk for a slip-and-fall claim while Low-Traction surfaces present the highest risk.
In 2012, the ANSI B101 main committee published the ANSI/NFSI B101.3 “Test Method for Measuring Wet DCOF of Common Hard-Surface Floor Materials” standard. Like the B101.1 standard, the B101.3 standard provides both a test method and table by which the user can interpret the resultant COF data. Walkways whose wet DCOF value is equal to or above 0.42 are defined as “High-Traction”, while values between 0.30 and 0.42 are considered “Moderate Traction” and values below 0.3 are ranked as “Low Available Traction.”
When tested to either the ANSI/NFSI B101.1 or B101.3 standards, most polished concrete surfaces, regardless of grit size used, will typically fall in the High-Traction range. This raises the question: which standard should the polished concrete industry use? Wet SCOF per the B101.1 standard or wet DCOF per the B101.3 standard?
Unlike the B101.1 standard, which is prohibited for use on highly polished surfaces, the B101.3 standard specifically applies to surfaces such as polished concrete and states this in the standards Scope statement. In short, the B101.3 standard is the only nationally recognized standard for measuring the slip resistance of polished walkway surfaces, like that of polished concrete, in an installed condition. Shortly after its publication, the Concrete Polishing Association of America (CPAA) published the following position statement:
” ... in the absence of a prescribed methodology for measuring the slip resistance quality of a bonded abrasive polished concrete floor and the lack of a coefficient of friction regulatory requirement, CPAA takes the following position:
Bonded abrasive polished concrete floors shall be tested for slip resistance by measuring the wet dynamic coefficient of friction using an approved tribometer according to ANSI/NFSI B101.3 Test Method for Measuring Wet DCOF of Common Hard Surface Floor Materials and shall achieve a Slip Resistance Potential rating of Acceptable (not less than 0.30 for level or inclined surfaces).
It is the belief of CPAA that the Dynamic Coefficient of Friction method is the appropriate method of measuring slip resistance of bonded abrasive polished concrete floors because the method holds floors to a tighter tolerance than the Static Coefficient of Friction method.”
As members of the ANSI B101 committee and B101.3 sub-committee, the Tile Council of North America (TCNA) was one of the architects who crafted the B101.3 wet DCOF standard. The TCNA is a trade association and lobbyist for the ceramic tile industry and is also the secretariat of the ANSI A108 committee which authors the ceramic tile industry’s quality control standards, including the A137.1 “Standard Specifications for Ceramic Tile.” The ANSI A137.1 standard has been in publication for many years and according to its scope statement “…serves as the basis for acceptance and methods of testing [ceramic tile] prior to installation.” Prior to the most recent 2012 version, all previous versions of the A137.1 standard referenced the ASTM C-1028 Standard Test Method for Determining the Static Coefficient of Friction of Ceramic Tile and Other Like Surfaces by the Horizontal Dynamometer Pull-Meter Method.
Confusion grows with the introduction of the ceramic tile industry’s A137.1 standard
In 2014, the C-1028 standard was withdrawn as a valid standard and was not replaced. However, when the A137.1 standard no longer referenced the C-1028 test method, it did not reference the B101.3 DCOF standard but instead created a substitute DCOF test method they call the “Acutest.”
The Acutest is a wet DCOF test method that is substantively different from the ANSI B101.3 wet DCOF test method. This change in the A137 standard has drawn much attention and has created a lot of confusion since its publication in 2012. Because the “Acutest” utilizes only one half the amount of surfactant in the wetting agent, the coefficient of friction readings are necessarily higher than the ranges outlined in the B101.3 standard when tested on the same test surface. This is unfortunate as many assume they are using the same test method because they both test wet dynamic coefficient of friction. However, the fact that both standards utilize wet DCOF is where any similarities end and the major differences begin.
Going back to the Scope statement of the A137.1 standard, which serves as a description of the standards limits, the reader finds that the “Acutest” applies only to ceramic tile which has not been installed as a floor but only to tile produced at the factory which has yet to be shipped to the customer and installed. The A137.1 standard is simply a manufacturer’s quality control standard and is limited to pre-installed ceramic tile. Any measurement of COF is not to be construed to imply a basis of safety. Contained in the A137.1 standard is a “Notice of Disclaimer” which in-part states that: “This information does not purport to address safety issues or applicable regulatory requirements associated with its use.” Again, affirming that the standard is not a safety standard and should be cited with caution.
This past February, the polished concrete industry was lobbied at the World of Concrete convention to discontinue the use of the B101.3 standard and adopt the A137.1 standard as its endorsed test method. It is unclear as to what course the polished concrete association will take, but the continued campaign of confusion being waged by the ceramic tile industry does not benefit the polished concrete industry. One example of the confusion being brought is in the area of litigation. Standards can be very confusing to a layperson but can become critically important in matters of litigation. Misapplied or improperly referenced safety standards can dramatically affect the outcome of a lawsuit.
What does this have to do with polished concrete?
Sadly, it is often under questioning from a skilled plaintiff’s attorney that business owners discover that the industry standard they reference for testing is actually incorrect, creating additional problems. Once a skilled plaintiff’s attorney learns that the defense is founded on an improperly cited industry standard, the case will often swing to the Plaintiff’s favor. Slips and falls are a big problem for customers of polished concrete and ceramic tile alike and utilizing the appropriate safety standard plays a vital role in preventing slip and fall events as well as building a viable defense when sued.
For more than a decade, the National Floor Safety Institute (NFSI) has been certifying products per the ANSI/NFSI standards. These products include a wide range of polished concrete products and application systems. Many of the manufacturers of the products that are used within the polished concrete industry are NFSI certified whereby a growing number of end users, including architects and specifiers, have come to rely on the NFSI certification program and often include such in their specifications. If the polished concrete industry chooses to abandon the use of the B101.3 standard and adopt the A137.1 standard, the benefits gained by the NFSI Certification process will be negated. Additionally, since the NFSI certifies products to ANSI B101 standards and not to the A137.1 standard, polished concrete products bearing the certification label will no longer apply and will not be accepted by the architectural industry. In short, when you are sued, an experienced attorney will ask why is it that you no longer use the safety standard for polished concrete but rather use a quality control standard for uninstalled ceramic tile.
What about NFSI Certified products?
Many slips and falls occurring on polished concrete are the result of its highly reflective surface, which often makes it difficult to see a wet hazard. Ultimately, polished concrete surfaces, like that of all walkways, should be kept clean, dry and free of hazards. Long-term benefits are gained through proper maintenance protocols and frequent inspections, all of which should be communicated to the end-user. Walkway testing and product certification enhance the long-term success for both contractors and customers but because of its smooth surface, it is vitally important that polished concrete be kept free of dry contaminants like paper dust, sand, or other small particulates. Falls aren’t funny and neither are lawsuits. Having and implementing the appropriate slip resistance safety standards protects everyone.
Many slips and falls occurring on polished concrete are the result of its highly reflective surface, which often makes it difficult to see a wet hazard. Ultimately, polished concrete surfaces, like that of all walkways, should be kept clean, dry and free of hazards. Long-term benefits are gained through proper maintenance protocols and frequent inspections, all of which should be communicated to the end-user. Walkway testing and product certification enhance the long-term success for both contractors and customers but because of its smooth surface, it is vitally important that polished concrete be kept free of dry contaminants like paper dust, sand, or other small particulates. Falls aren’t funny and neither are lawsuits. Having and implementing the appropriate slip resistance safety standards protects everyone.
Russell J. Kendzior
As the Founder and Chairman of the Board of the National Floor Safety Institute, Russell Kendzior is recognized worldwide as one of the leading safety experts specializing in slip, trip-and-fall prevention. As President of Traction Experts, Inc. Mr. Kendzior has consulted with numerous fortune 500 corporations and has been retained as an expert witness on more than 600 slip, trip-and-fall lawsuits.
Mr. Kendzior is the Secretary of the ANSI B101 Committee For the Prevention of Slips, Trips, and Fall’s and is a past member of the Board of Delegates of the National Safety Council. Mr. Kendzior has been an active member of eight ASTM committees, and is a member of the American Society of Safety Engineers, the American Society of Mechanical Engineers, and a past member of the International Code Council.
Sought nationwide as a safety consultant, public speaker, and expert witness, Mr. Kendzior is the author of the best selling book on accident prevention entitled, “Slip and Fall Prevention Made Easy”, and in 2010 authored his second book “Fall’s Aren’t Funny,” Mr. Kendzior has written a wide range of articles on the subject of floor safety. Mr. Kendzior has appeared on numerous nationally televised programs including: Inside Edition, Good Morning America, CBS News” and “ABC News Primetime “What Would You Do”
Mr. Kendzior is the author of the “OSHA Self-Inspection Checklist” (A.M. Best Company, 1997-current) and has written numerous articles on slip-and-fall accident prevention for such industry publications as Chain Store Age, ISSA Today, Services Magazine, Texas Lawyer, Attorney at Law, and Professional Retail Store Maintenance Magazine (PRSM).
Mr. Kendzior frequently lecturers various trade and professional associations including: The National Restaurant Association, The International Textile Rental Association, and the International Sanitary Supply Association. He has also spoken before numerous manufacturing groups representing the floor mat, floor care, and the floor coverings industries.
For more information about the NFSI or ANSI B101 standards please feel free to visitwww.nfsi.org. Mr. Kendzior can be contacted at:
P.O. Box 92628
Southlake, TX 76092
(817) 749-1705
russk@nfsi.org