Healthcare estates and facilities managers and flooring manufacturers are being urged to stop relying on ‘R’ values taken from ‘unreliable’ Ramp Tests and to instead use Pendulum Test Values to gauge the slip resistance of flooring materials in the future.
Speaking at this year’s Surface Design Show in London, Lucy Jones, specification manager at Johnson Tiles, the UK’s largest manufacturer of wall and floor tiles, called for a change in mindset when procuring safety flooring solutions for high-risk health and social care environments.
She revealed that commonly-used ‘R’ values, derived from Ramp Tests, are deemed by the UK’s Health and Safety Executive (HSE) to be unreliable due to the fact there are too many ‘uncontrolled variables’ in the testing method.
In health and social care settings, the issue of safety is hugely important as slips, trips and falls cost millions of pounds and have a serious impact of patients’ and service users’ lives
Instead, she urges health and social care trusts to work to Pendulum Test Values (PTVs), with a score of 36 or above being the minimum requirement in either wet or dry conditions.
“It is necessary to carry out a risk assessment when thinking about what floor coverings to put into buildings,” she told the conference.
“And, particularly in health and social care settings, the issue of safety is hugely important as slips, trips and falls cost millions of pounds and have a serious impact of patients’ and service users’ lives.”
The science
In scientific terms, a slip occurs when the force required to stop a body is not matched by the frictional force between the body and the floor at the point where a person’ heel touches the surface.
Certain environments are more likely to induce trips, slips and falls, for example entrance areas and bathrooms.
Jones said: “When choosing flooring you have got to think about the contaminants that are likely to occur. Is it a kitchen, where there may be food spillages? Or a bathroom, which will be wet and where people are likely to be walking in bare feet?
“You also need to consider what sort of footwear, if any, people will be wearing and whether they will they be walking or running, or will they have disabilities?
“All these things need to be considered before you can decide what level of slip resistance you need.”
Slip resistance is a measure of the co-efficiency of friction of a floor and is measured in U values. Currently, there are three main testing methods – the Ramp Test, the Pendulum Test, and Tortus.
The now-favoured Pendulum Test imitates the heel impact and can be used on wet or dry surfaces. The HSE favours this method as the machine used is quite small and portable and it is deemed to be more accurate. It has a swinging arm with a rubber slider, which mimics the action of heel when walking.
A matter of risk
It gives an overall PTV score for a flooring measured in three different directions and across five separate measurements. High risk is 0-24, moderate is 25-35, and over 36 is considered low risk.
“This is seen as the most-scientific method,” said Jones. “It controls more of the variables and is most realistic in terms of what happens when we walk.”
When choosing flooring you have got to think about the contaminants that are likely to occur and what sort of footwear, if any, people will be wearing
In contrast, the Ramp Test is a German method where a person is harnessed to equipment. They stand on flooring in heavy rubber boots and walk up and down while the gradient of the surface changes. For dry results, motor oil is poured onto the surface, while to measure what would happen in wet conditions, a soap solution is used. The person walks until they slip. For a dry surface this results in an ‘R’ rating, with R9 denoting the most-slippery environment, and R13 the least slippery. For wet surfaces, ABC ratings are used, with A the most slippery, and C the least.
The Tortus – or sled – test is a small machine based on a stylus, which creeps across the surface of a floor and measures the roughness. However, this can often lead to misleading results depending on the texture of the surface and whether there are lots of grout lines. But it is seen as a useful back-up option for the Pendulum Test where that will not work as well, for example on stairs where there is not enough room for the pendulum arm to swing.
Ignore ‘R’ values
“With most architects and designers, the first thing they talk about when specifying flooring is ‘R’ values,” said Jones.
“But, if delegates at this conference take one thing away, it is to please start ignoring ‘R’ values.
If delegates at this conference take one thing away, it is to please start ignoring ‘R’ values. If someone slips and the case goes to court, the HSE does not see this as a viable or modern method of testing
“If someone slips and the case goes to court, the HSE does not see this as a viable or modern method of testing. It used to be good enough, but it isn’t any more.
“You can use ‘R’ values for reference, but for specification we need to stop using them.
“The Pendulum Test, whether wet or dry is what we all need to be referring to in the future. That’s what will stand up in court.
“For our flooring products we now give PTVs and ‘R’ values as a comparison and we urge other manufacturers to do the same.”
She also spoke of the importance of good cleaning regimes, with all grout removed when floor tiles are laid as this can affect slip resistance, adding: “It’s not just about specifying the right product. We need to make sure we finish installations properly, we clean floors properly, and that they are dry.”
