Slippery Floors

What causes floors anywhere in commercial buildings or a home to be slippery? I am sure the first thing you thought of was “a wet floor” and you would be right. Why then, would or could someone slip on a supposedly dry floor? 

Vinyl Composition Tile (VCT), Terrazzo, Marble, Ceramic Tile, Polished Concrete, Luxury Vinyl, you name it, if it’s a hard, smooth surface, it can be slippery when wet and sometimes when it is dry. And the reason why is due to a low coefficient of friction (COF), at that time. 

One definition of COF is “The ratio of the force that maintains contact between an object and a surface and the frictional force that resists the motion of the object.” Unfortunately, many of us may have already participated in the definition of COF if you ever slipped on a floor, ice, tub/shower, slime covered stones, etc., etc. You have “firsthand” experience in that law of physics and the ever-present law of gravity. <OUCH> 

I have seen where an overabundance of fine particulate soil such as drywall dust or pellets of ice melting compounds prevented the sole of a shoe from contacting the floor's surface, making it slippery and causing low COF. This would be an example of a dry floor being slippery.  

Soil, water, oil, or detergent residues can all play a role when it comes to slippery floors. Any amount of water between the sole of a shoe and the floor is the most common cause. Look what happens with the tires on your car and the road when it’s raining. Oil for sure is a cause, especially in food service areas or by the front doors coming off an asphalt parking lot. Another source that is sometimes overlooked is the detergent being used to clean the floor regularly. 

RESIDUE ON THE FLOOR 

What type of residue is being left on your floors by the detergent you use after cleaning them? Is the dispensing system (metering device, measuring cup or glug) you use giving the proper dilution ratio for the floor being cleaned?  

I recall a case where a heavy detergent residue was causing slipping issues on a terrazzo floor. That is tragic, but the residue left on the floor was so bad it was contributing to heavy soiling on adjoining carpeted areas. The dispensing system did a fine job of diluting the proper amount into the auto-scrubber being used in parts of the facility, but it was the wrong dilution ratio where the floor was being mopped. Good detergent, wrong dilution for the application.  

Why was that happening? A walk behind machine applies the detergent to the floor, agitates it with a pad or brush, and vacuums up the soil and cleaner leaving a dry floor. Whereas, when mopping the floor, you are leaving detergent-laden water on the floor to dry on its own. That light film of detergent builds up over time causing the issue. So, make sure your dispensing system is diluting the detergent properly for the procedure being used. 

The National Floor Safety Institute (NFSI) tested common household cleaners for their slip resistance and made their information available for public review in their January 2023 NFSI Household Floor Cleaner Study. They found products that actually caused the floor to lose COF after being used; in other words, they made the floor slipperier. January 2023 NFSI Household Floor Cleaner Study | NFSI  

Obvious things like soil, water and oil can cause floors to be slippery. A not so obvious culprit can be ice melting compound and/or salt. Are you aware that calcium chloride, the most common ice and snow melting product, is a type of desiccant? The term desiccant is a fancy word for hygroscopic, meaning, it attracts moisture, moisture that is in the air. You may have heard of a product called DampRid, non-electric dehumidifier. Small containers you place in a damp closet. The primary ingredient in those little containers is calcium chloride. Enough already! NO MORE CHEMISTRY TALK! Why should I be concerned about this Mark? 

If a film of calcium chloride or salt is left on the floor after it is mopped, your floor will take longer to dry, and in some cases, never truly dry and be slippery. 

BOTTOM LINE 
A damp floor is a dangerous floor, and so are soiled floors. An improperly maintained floor can also cause it to be slippery. Not getting the film of salt or oil off the floor properly or using the wrong detergents, the wrong dilution ratio, or the wrong method of application can cause a floor to become slippery and stay slippery.