How Slippery is Too Slippery for Floor Tile?

Learn how to use various tile ratings to guide your search for a safe floor tile.

Are you excited about installing a new tile floor, but concerned about the possibility it could be too slippery? Tile manufacturers know how you feel. That’s why tiles carry ratings to provide information about their slipperiness under various conditions.

Coefficient of Friction

The most comprehensive and robust single measure of tile slipperiness is provided by The Ceramic Tile Institute. This measure takes into account both wet and dry conditions, as well as the slope of the tile and the speed of the person walking on it. Based on their testing, The Ceramic Tile Institute categorizes tile into three groups:

• Slip Resistant: Tiles with a coefficient of friction of 0.60 or greater when wet are considered the safest and meet or exceed ADA and OSHA requirements. These tiles would be suitable for wet areas like pool decks and bathroom floors.
• Conditionally Slip Resistant: These tiles have a coefficient of friction between 0.50 and 0.59. While they do not meet ADA standards they do meet OSHA standards and are considered safe for most applications.
• Questionable: Tile with a coefficient of friction under 0.50 are not considered safe for use in wet areas, and in fact are best avoided in all flooring applications. These tiles are typically designed to be used as decorative wall tile.

DIN Classification

DIN, which is the German Institute for Standardization, also produces ratings for floor tile. You may encounter these ratings on European tiles. The DIN arrives at their ratings by installing the tile on a surface whose slope gradually becomes steeper and steeper. Then they have a test subject wearing normal shoes walk up the slope until they begin to slip. Both wet and dry tiles are tested to arrive at two separate ratings as follows.

• Dry Tile: Tiles are rated from R9 to R13, with R9 tile beginning to cause slippage at a slope of 10 percent and R13 tile providing adequate traction at slopes up to 35 percent. The higher the R rating the less slippery the tile.
• Wet Tile: Tiles are also tested when wet and given a separate rating of A, B, or C. Rating A is the most slippery, causing slippage at a 12 percent slope. Rating B is better, providing traction on slopes of up to 18 percent, and Rating C is the best, providing traction on wet tile slopes of up to 24 percent.

Pendulum Skid Resistance Test

One final tile slipperiness rating you may encounter comes from the Pendulum Skid Resistance Test. Based on this test, tiles are rated from 25 (very slippery) to 66 or higher (not at all slippery). A rating of anywhere from 35 to 65 is considered good for floor tile.

Need Help Picking the Perfect Floor Tile?

If you would like help selecting the perfect floor tile for a given room in your home or business, please stop by our showroom. Our tile design specialists will be happy to help you find a tile that looks and performs great.