Coefficient of Friction

by Kennadie McDermott
on 09 September 2019

slip

What is Coefficient of Friction and why is it important?

Tiles come in many finishes, the most popular two being honed and polished. Many homeowners and designers start the design process by determining what finish they would like the tile to be because they are worried about slippage. Determining what tiles have a COF suitable for your floor tile is the first step in deciding which tile you are going to select.

Definition of The Coefficient of Friction (COF): COF is the ratio of the force of friction between an object and a surface to the frictional force resisting the motion of the object. To measure the friction between a surface (tile) and an object you must first determine how much force is required to move an object horizontally across that surface. 

The higher the COF the more resistance there will be for movement. This means that a COF of .7 is more resistant to slipping than a tile with a .5 COF.

Additionally, there is a DCOF rating, which is Dynamic Coefficient of Friction. Once you are slipping, DCOF comes into play. When a floor is wet the amount of static friction has been reduced and once you are slipping you create dynamic friction. The more dynamic friction there is the slower a foot will slide across the floor.

One of our new products this year is Montac. Montac has an R11 rating and a DCOF of .62. This means that this product has enough texture to be safe for use around pools, in bathrooms, saunas or any area that gets wet frequently.

Montac

Montac is just one example of a product with a high DCOF rating. Many Surface Art products are rated for commercial and residential use.

A frequently asked question is do you have to give up polished tile for safety? Typically, a polished tile will not have a COF rating high enough to be suitable as floor tile. But do not let this discourage your dream of having a polished floor. There are many other tiles that have a shine or glaze that are suitable for floor usage to give you the polished look you are going after, while maintaining safety.

Gusto, has a double glazed deco and is also floor rated. As seen below, the deco gives a polished glaze look in random geometric patterns.

Gusto black double glazed deco

Want to know more about COF? Check out our education page here.