All buildings incorporate a range of floor coverings. For instance, offices are usually carpeted, kitchens and toilets usually contain sheet vinyl or stone tile. Whatever the floor type, each has its own particular characteristics, one of which will be their ability to resist slips when people travel across them.

Generally, the efficient application of a floor seal or polish will increase the slip resistance of the floor surface. However, if the seal or polish is not applied correctly, or is allowed to become contaminated with soil or grit, it will not adhere to the surface properly, therefore reducing the slip resistance of the floor. Similarly, the slip resistance of a floor will reduce if they are allowed to become wet.

If anti-slip flooring is polished, its slip resistant qualities will be reduced, due to the polish smoothing out the surface. The slip resistance of polished floors is measured using the “Coefficient of Friction”.

What is a Coefficient of Friction?

There are two types of friction and friction coefficients; static and dynamic. The static coefficient of friction measures the amount of energy required to move a stationary object across a surface. The dynamic coefficient of friction measures the energy required to keep an object moving. If you have ever moved furniture you will understand the difference. Getting a bookcase moving from a stationery position and getting it across a room require different levels of energy.

Both types of friction can be quantified as follows:
Measuring the coefficient of friction of flooring is the most common way to determine the expected safety of the surface. Most manufacturers of floor coverings publish this data and make it available to customers. However, comparing data from different manufacturers isn’t as straightforward as it might seem.

Most manufacturers of floor coverings measure the static coefficient of friction. Any two surfaces, like a rubber platform shoe and dry deep-pile carpet, will have a relatively constant static coefficient of friction; replace the rubber soled shoe for new leather sole and the friction between the two surfaces is significantly reduced.

Likewise, different testing conditions used in the various test methods yield different results. This is due to the fact that there are at least seven different methods for testing coefficients of friction for floors and floor coverings.

The most common method of measuring slip resistance uses a 50lb weight placed flat on a leather shoe heel, which is then placed flat on the floor surface being tested. The heel-and-weight assembly is pulled across the stone with a spring or electronic scale. The maximum amount of force (measured in pounds) needed to start the assembly in motion is recorded. This measurement is divided by the weight (50 pounds) and gives the coefficient of friction value.

Tests to measure slip resistance were developed primarily for man-made materials, with the earliest from the 1940s, when Sidney James conducted experiments to rate floor polishes and other floor maintenance chemicals. From these experiments
came the James Machine (ASTM D-2047) and the 0.5 static coefficient of friction as the threshold was established as the safety benchmark for normal walking across a surface.

Unlike other test methods, the James Machine can only be used in a laboratory for testing smooth, dry surfaces, and test results cannot be compared to those of other test methods. However, portable test meters, more commonly referred to as “pull meters” are available that can measure the levels of friction which incorporate the same principles. Many cleaning contractors carry out their own tests on polished floors for safety purposes.

There are several procedures that building owners, cleaning companies and others can take to minimize the risk of accidents involving slips and falls, examples of which are as follows:

• Pay attention to areas where water is present or spills can occur. Barrier mats should be placed inside the entrance of doors before and during wet and inclement weather. Spilled food and drinks can create slippery conditions on the floor, and any spills should be cleaned up as soon as they occur.

• Floor maintenance procedures involving wet mopping or stripping and redressing floors should be undertaken outside of normal working hours in order to minimise the amount of pedestrian traffic.

• Always place “Wet Floor” signs at the extremes of the work area where cleaning is taking place, regardless of the time of day or night. Floor cleaning personnel should also verbally warn people who may walk across the floor that it might be slippery.

• Keep accurate records on the maintenance of floor surfaces. Include in your records the brand names of all products used on the floor, specific procedures that are performed on the floor and how often and who performed these procedures.

• Keep a daily log of maintenance procedures. Designate one individual to keep track of the log, perform routine inspections of the floor and record findings during inspections.

It is important when caring for floors to be fully aware of the make-up and characteristics of the floor itself. The best way to do this is, if possible, retain the name and address of the flooring supplier and any information provided by them following installation. This information will contain a detailed explanation of the materials used to construct the floor along with directions for cleaning.

For more information contact Janitorial Express on 020 7700 3322 or email sales@janitorialexpress.co.uk

To ensure you receive the next update, enter your email address above for your free subscription to this Blog.