Around 67% of falls on the walking level occur because of slips and trips from wet and oily surfaces, extra tile glazing, weather hazards, traction differences, and much more. The dynamic coefficient of friction (DCOF) test method specified in NFSI B101.3-2022: Test Method For Measuring The Wet DCOF Of Hard Surface Walkways enables common hard-surfaced walkway materials to be tested and measured before their purchase so that falls, trips, and slips on floors are minimized.
What Is DCOF?
DCOF, or dynamic coefficient of friction, is a measurement that determines how much friction (i.e., the force that resists the sliding motion of one surface against another) there is on wet, level floors when walked upon. It is primarily used by the tile industry to identify suitable applications for a floor product. The results of DCOF testing help determine the likelihood if a tile surface could contribute to someone slipping and/or falling. DCOF is a main consideration when it comes to choosing the tile for an area, especially when selecting tiles for areas that may be subjected to water, oil, or grease exposure. The DCOF test method detailed in NFSI B101.3-2022 is used to show the level of friction present on wet floors when walked upon.
What Is NFSI B101.3-2022?
The test method in NFSI B101.3-2022 specifies the procedures and devices used for both laboratory and field-testing to measure the wet dynamic coefficient of friction (DCOF) of hard-surface walkways. This standard provides a measurement procedure setting forth DCOF ranges which facilitate remediation of walkway surfaces when warranted. The test method addresses the common hard-surfaced walkway materials, such as ceramic and porcelain tile, polished and un-polished concrete, stone, vinyl, wood and synthetic laminates, and such materials with coatings or polishes applied.
The test method in NFSI B101.3-2022 does not apply to any type of carpeting.
DCOF and Tiles
The very feature that makes tile easy to clean—its smooth, non-porous nature—also means that it is slippery underfoot. Tile glazing and wet conditions make tiles even more slippery. Luckily, DCOF testing allows us to see how tiles will perform under different conditions, so dangerous slips are avoided before purchasing the tile. ANSI A137.1:2022 – Standard Specifications For Ceramic Tile requires tile flooring products to have a DCOF of 0.42 or greater if recommended for use in a level interior space intended to be walked upon when wet. ANSI A137.1 is based on wet DCOF measurement performed according to ANSI A326.3, the standard for DCOF of hard surface flooring materials. ANSI A326.3 Wet DCOF measurements are based on specific standard practices under controlled conditions. These measurements provide useful information for comparison of product performance, but measurements should not be considered as an indicator of whether a slip can occur.
What Is a Good DCOF Rating?
DCOF ratings are on a scale 0.00 to 1.00 µ. NFSI B101.3-2022 specifies that anything below <0.30 DCOF requires professional intervention, anything between 0.30 – 0.44 DCOF should be monitored and tested regularly, and ≥0.50 (ramp)/ ≥0.45 (level surfaces) do not require any immediate action. Here are some recommended DCOF ratings for tiles:
- Level areas that are likely to be walked on when wet, including lobbies, supermarkets and toilet facilities: ≥ 0.42
- Wet areas where light or no footwear is used, including pool decks, steam rooms and showers: ≥ 0.60
- Areas that could be exposed to water, where footwear is typically used, including walkways or patio areas: ≥ 0.60
- Areas that could be exposed to oils, greases or fats, including automotive warehouses, garages, catering areas, areas involving deep-fry and grill equipment and other food preparation areas: ≥ 0.60
- Inclined areas or ramps, including stairs, wheelchair ramps or loading bays: ≥ 0.65
NFSI B101.3-2022: Test Method For Measuring The Wet DCOF Of Hard Surface Walkways is available on the ANSI Webstore.