ANSI A326.3 is the American national standard for measuring the wet slip resistance of hard flooring. It uses a test called dynamic coefficient of friction, or DCOF. For level interior floors expected to be walked on when wet, it sets a minimum value of 0.42. The standard’s measurements are meant for comparing products, not predicting whether a person will slip.
What ANSI A326.3 Means for Your Floor
Think of the 0.42 number like a minimum tread depth on a tire. It tells you a floor passed a baseline grip test with water on it. The standard says flooring for level interior spaces expected to be walked on when wet with water shall have a wet DCOF of 0.42 or greater. Wetter or outdoor spots need more grip, such as a 0.60 minimum for exterior and pool areas.
Passing doesn’t make a floor slip-proof. These results shouldn’t be considered an indicator of whether a slip can occur. Spills, oil, soap film, worn shoes, and poor cleaning all lower real grip.
The standard started in the tile world, but coating makers use it for resin floors too. Even then, a floor that meets 0.42 isn’t automatically right for every project.
ANSI A326.3 FAQ
What does DCOF 0.42 mean?
It’s the minimum wet grip value the standard sets for level indoor floors that may get wet. A floor that tests at 0.42 or higher meets that baseline. It doesn’t guarantee nobody will slip.
What is a good slip resistance rating?
For indoor floors that may get wet, look for 0.42 or higher. Outdoor areas and pool decks call for 0.60 or higher. Keeping the floor clean and dry matters as much as the number.