Watch your step: Specifying non-slip flooring
By Steve Urwin Marketing Manager TARKETT UK.
SLIPS and trips account for over a third of all major injuries to workers every year according to the Health and Safety Executive (HSE). With the yearly cost to employers £512m and the health services £133m, the importance of specifying a flooring system which has a non-slip surface cannot be overstated.
In a marketplace where no two floor types are the same, how can specifiers play their part in reducing these shocking figures and ensure the flooring they specify offers a slip-resistant finish in the long term?
Slips and trips may well be the number one risk when it comes to injuries at work and they can occur across all industry sectors. Workplace (Health, Safety and Welfare) Regulations 1992 set out the safety measures an employer must follow to protect workers requiring floors in a workplace must not be slippery, holed, sloped, or uneven, so as to expose any person to a risk to their safety.
A slip-resistant floor will protect staff and visitors against an unsafe slip hazard and meet the requirements of the manufacturing standard, EN 13845, which considers wear resistance and the sustainability of slip resistance properties.
What is a safety floor? How do we define it? How long will it last? A floor can be in one of two states – as it comes out of the factory – dry and new in top condition, and it’s evaluated for slip resistance in that state.
But when that same floor gets wet, this aesthetically-pleasing and walkable floor transforms into something that is potentially hazardous. This can lead to claims against the building owner, the installer and even the person who specified the flooring system in the first place.
The key to particle-enhanced slip resistant flooring is the manufacturer’s guarantee for slip resistance – both in the wet and in the dry; not just on the day it is installed but in 10 years’ time. As the floor wears, there are crystal granules – silicon carbide or aluminium oxide – at different depths within the wearlayer that are constantly being exposed as the floor surface wears under foot traffic. There are various test methods that prove this point.
The alternative is a slightly rough, embossed surface layer which will test as slip resistant when new, but won’t withstand the rigours of regular traffic. In this latter case, as the emboss providing the coefficient of friction is made from PVC, it’ll flatten very quickly and when it’s worn away, it’s gone.
After a couple of years or even less, what you thought was a safety floor has become a nicely polished, smooth vinyl floor which is no longer compliant to HSE guidelines or EN13845. This potentially leaves the building owner and his supply partners open to risk.
Generally, a heterogeneous vinyl safety floor will have a polyurethane (PU) lacquer on the top surface to resist scuffs and stains. Owing to the product needing to have a rough surface, by definition, in order to fulfil its purpose, dirt can readily be walked into the spaces between the particles. If not regularly and correctly maintained, this will quickly build up and soil the floor.
You’ll unfortunately see this all too often if you look, especially with wood effect patterns to which the manufacturer has added a ‘wood tick’ emboss.
The ‘debossed’ areas of the surface are effectively tiny trenches which quickly fill up with dirt and the resulting visual is quite unpleasant and difficult to rectify.
New technology allows manufacturers to apply coatings in a more sophisticated and uniform way. The coating may be applied to the surface of the floor using an ‘Air-Knife’. This process involves the lacquer being ‘blown’ under pressure onto the top layer.
The ‘Air-Knife’ ensures every irregularity in the surface is fully covered and sealed by the stain-resistant PU coating to make the floor easier to clean and ensuring it looks good for longer.
In terms of VOC performance, some manufacturers strive for the very best, and this PU lacquer serves a secondary purpose in reducing the already extremely low VOCs to non-detectable levels (=<10ug/m3). It helps create a ‘VOC-free’ vinyl flooring product and contributes to better indoor air quality.
The best way to ensure a floor is up for the job and safe is to specify and install a floor that meets HSE and European Standard requirements. On behalf of the HSE, the health and safety laboratory uses a two-part test to assess the slip resistance of flooring in dry and contaminated conditions.
The first is a pendulum friction tester also known as the portable slip resistance tester, and is detailed in BS7976 Part 1. It mimics the action of a slipping foot by swinging an imitation rubber soled shoe over a set area of flooring in a controlled manner. The friction produced by the shoe over the flooring is measured as the pendulum swings, by the angle.
A pendulum test value (PTV) of 36 or higher is classified as low slip risk. This test has shown over many years it gives good correlations between instrument results and actual incidents of pedestrian slip. The test itself is portable and can be used onsite or in a laboratory.
The second is a micro-roughness meter which is designed to supplement pendulum test data. The measurement of Rz using a handheld meter is quick and simple, with a surface roughness of 20 microns in wet conditions indicating a low slip risk.
In terms of the longevity of slip resistant flooring, the European test EN 13845 Annex D measures the sustainability of surface roughness by assessing the number of the particles left on the surface after wear to give a measure of sustained slip resistance.
If it exceeds 50,000+ cycles, flooring is awarded the top classification 34 / 43, classed as ‘very heavy commercial / heavy industrial’.
There are German test methods which are accepted in the UK and widely used by manufacturers. However, they shouldn’t be used in isolation. The ramp test requires an operator, either barefoot (DIN 51097) or in standard footwear (DIN 51130), to walk on a ramped surface which can be sprayed with a liquid containment at a prescribed rate.
Wearing a full harness, the operator can gradually increase the angle of the ramp until they feel insecure when walking up or down the slope. The angle at which the slipping occurs is used to establish a classification ‘R’ value for the shoe test and an A, B, C rating for the barefoot test.
In the barefoot test, a ‘C’ would be the best or most slip-resistant rating. For the shoe test, the scale ranges from R9 to R13, with R9 being the lowest. Safety flooring generally receives an R10 or higher rating.
It’s a useful test method as it can be used on heavily profiled surfaces which are difficult to test using the pendulum method. However, an R10 rating is no reassurance of sustainable slip resistance. Many domestic products are rated R10, but for commercial applications the EN standard 13845 is the one to look for.
While choosing the most appropriate slip resistant floor is important, choosing a floor that is easy to clean and maintain over time is also a high priority. Clean floors are safe floors. Surface contamination and poor maintenance can lead to a floor which is slippery and will not meet the required standard.
A further issue is that a coarsely textured surface can be more difficult to clean, with dirt accumulating around the granules. Knowing the best and most efficient way of cleaning a safety floor is key.
Of course, there might be a trade-off between surface roughness and cleaning, but manufacturers of safety floors will provide detailed information on recommended cleaning regimes. Microfibre flat mops, for example, are better than cotton string mops on safety floors as the tiny fibres are able to penetrate the microscopic surface pores of the flooring as opposing to skimming over the surface. This means the dirt is removed by the microfibre cloth rather than simply being moved around the floor, as tends to be the case when a more traditional mop is used.
For larger floor areas, machine cleaners with brush or melamine pads offer improved cleaning and dirt absorption. But the latter can wear down quickly so the onus is on the operator to change these pads otherwise they can be ineffectual and will spread dirt.
Neutral detergents are also important and with the correct dosage; too much of a chemical will make a floor stickier, attracting more dirt and leading to safety issues.
Designed for life
Tough, practical and hygienic, today’s modern vinyl safety flooring has moved on considerably from the ‘institutional’ looking, utilitarian flooring of the past and the marketplace now offers an extraordinary choice of decorative designs: from brilliant colours, abstracts and black and white, to near perfect reproductions of natural materials such as wood and stone.
The industry is also producing flooring with low emissions, which can contribute to well-being and healthy indoor environments.
However, it’s important for specifiers to recognise a product’s slip performance at the specification stage. A key consideration in any internal environment, a floor with inherent, sustainable slip resistant properties will safeguard against falls and personal injuries to staff and visitors alike. Reputable manufacturers and suppliers will have the knowledge and understanding of slip resistance and can be a valuable partner in the specification process to ensure the selected product is fit-for-purpose and will last for the long-term.