Tile Talk October 2021 | DCOF Refresher

Several years ago, the Tile Council of North America announced the new standard for measuring a tile’s frictional resistance.  The DCOF Acutest (A137.1) gave more detailed guidelines on how to measure the frictional resistance of an object already in motion. This means that as an industry we could now better understand the resistance of a tile’s surface when exposed to dynamic movement.

Consider these 5 topics when specifying your next tile project:

1) Minimum Requirement – In accordance with the guidelines set forth by The Tile Council of North America, tiles selected for level interior spaces with the expectation that they will be walked upon when wet, must have a minimum DCOF value of 0.42. This means that for a commercial environment, selecting tiles that meet this minimum value, is a good baseline. However, tiles with a lower value are not deemed unsafe or inappropriate, nor are tiles with a higher DCOF considered slip-proof.  The industry stresses the importance of considering all aspects, including but not limited to – type of use, cleaning regimen, exposure to contaminants, traffic, and manufacturer guidelines.

2) Exterior Applications – Unfortunately, there are no minimum DCOF values that are specific to exterior floors. However, I see the industry moving toward a consensus and addressing this issue as exterior tiled spaces have become increasingly more popular in recent years.  Not sure of a date, but I know it’s coming. 😊

3) Other Areas to Consider – Nowadays, specifying tiles in areas that were historically avoided are much more common than not. Many of our clients choose to extend the tile footprint into areas such as stairs, ADA ramps, walkways, and other areas with slight inclines.  Although there is no industry-backed DCOF value for these types of areas, here at CMC, we recommend starting with tiles that have a DCOF value of 0.60 or higher.

4) SCOF? – Before 2012, the tile industry used a static coefficient of friction value to determine the slip performance of a tiled floor. However, this test measured the frictional resistance one pushes against when starting in motion. It did not take into account dynamic movement when already in motion.  Make sure your tile partner provides DCOF values (not SCOF) when specifying your tiles.

5) Does Tile Size Matter? – Yes, it does! The smaller the tile, the higher number of grout joints. This means that the DCOF value of a grouted mosaic tile is higher when compared to a single individual tile.  Probably explains why we still see a ton of mosaic tiles for commercial locker rooms, steam rooms, saunas, and pool decks.


As the worldwide leader in testing and standards creation, The Tile Council’s improved language and guidance has helped catapult the DCOF value to worldwide acceptance and is now the premier test for our global tile partners.

Remember, leaning on DCOF values alone will not get it done.  It is the combination and utilization of the DCOF Acutest with a sound understanding of the requirements of the space.  This thoughtful approach will guarantee the best results for your project.

Until next time…. Ken