Slip resistance
Properties of a floor covering with regard to slip-promoting substances, such as water, are summarized under slip resistance or slip resistance . The question of why a person slips or falls is relatively easy to answer. Anyone who loses control of their center of gravity can fall.
There are a variety of factors that affect slip resistance. These can not only be in the flooring itself, but also e.g. B. in the environmental factors, in the people and in the specific circumstances. All influencing factors cannot be presented here and cannot be included in any test in a realistic manner. The slip resistance of people is particularly at risk on wet and smooth floors, because an aquaplaning effect can occur when walking on them.
Test methods
Around 21% of all reportable accidents at work in 2018 were caused by tripping, falling and slipping. The reasons for slipping lie in the design of the floor and footwear as well as in their soiling. The number of accidents has decreased since there were regulations on slip safety in Germany. There are a number of test methods for the slip resistance of floor coverings, both on site and in the laboratory. The Institute for Occupational Safety and Health of the German Social Accident Insurance carries out such tests - as an orientation test or as a type test (with test certificate and DGUV test certificate).
- Historical test methods
In the 1930s, a ceramics manufacturer that no longer exists set up the first test set-ups to simulate the problem in the laboratory. A slope was built that had been let in with oil. Subsequently, attempts were made to change the slip properties by means of alternative surface designs.
Test methods in the laboratory
General work areas
The test according to DIN 51130 is carried out as follows: The covering to be tested is placed on a test frame and 200 ml per square meter of a special motor oil is applied. A test person walks on the surface with standardized work shoes while it is lifted over the rear edge. The examiner runs up and down the ramp, which becomes steeper and steeper, until he slips or feels unsafe. The angle of inclination of the pavement or the ramp finally achieved is measured. The number of degrees determined by this procedure by means of two test persons leads to the classification in the evaluation group below. An "on-site measurement" and inspection of the pavement after a certain period of use or renovation is not possible with this method according to DIN 51130. This is criticized from many sides.
Slip resistance
values R with degrees: (without values for "displacement spaces", which are located below)
| R value | Degrees |
|---|---|
| R 9 | 6 ° - 10 ° |
| R 10 | > 10 ° - 19 ° |
| R 11 | > 19 ° - 27 ° |
| R 12 | > 27 ° - 35 ° |
| R 13 | > 35 ° |
Displacement spaces:
In work areas in which greasy, pasty or fibrous-viscous substances get on the floor, tiles may also have to have a “displacement space”. This displacement space lies between the shoe sole and the floor covering, the open cavity that lies in between. This is divided into four V classes. A V value indicates the minimum amount of liquid in cm³ the soil has to absorb on one dm².
| group | Minimum volume |
|---|---|
| V4 | 4 (cm³ / dm²) |
| V6 | 6 (cm³ / dm²) |
| V8 | 8 (cm³ / dm²) |
| V10 | 10 (cm³ / dm²) |
Wet barefoot areas
The structure according to DIN 51097 is similar to the above-mentioned DIN 51130. On the same device with the adjustable inclined plane, relaxed water is applied as a lubricant instead of oil. The test persons are barefoot.
| Assessment group | Minimum angle | Application example |
|---|---|---|
| A. | 12 ° | Locker rooms |
| B. | 18 ° | Shower rooms, pool surrounds, steps to diving pools |
| C. | 24 ° | Walk-through pool |
On-site test methods
In order to test a pavement “on site”, various devices were built, which are presented below in chronological order. What they all have in common is that from evaluation group R10 onwards there is no possibility of subsequent testing with sliding friction measurement methods.
Cobbler
The first was the so-called “shoemaker device”, a weight block with rubber blocks on the underside that is pulled across the floor. A spring balance was used to measure how much force had to be applied during the sliding movement. The ratio of the weight of the device and the tensile force gave the dimensionless coefficient of sliding friction. The result was subjective as it depended on the person of the examiner. Therefore, in order to objectify the test result, an electronic variant was considered.
SRT pendulum
This pendulum tester with the SRT pendulum comes from England and is listed in the European standard for outdoor areas. In the country of origin it is rejected due to inaccuracies. The “Research Society for Roads and Transportation e. V. ”, Cologne, published a leaflet in 1997 about the“ slip resistance of pavement and paving for pedestrian traffic ”, in which the determination of the sliding friction values, the“ SRT values ”, is explained. The outdoor areas also include floor coverings that are exposed to rain or snow through the entry of wind, for example covered entrances. When measuring with an SRT device, a calibrated pendulum is used for the micro-roughness and a discharge meter for the macro-roughness. The outflow meter is a cylindrical measuring container with an elastic sealing ring that is placed on the floor covering. The container is filled with water and the amount of liquid flowing out is measured over a defined period of time. Both values are converted to an SRT value. With the SRT method, new panels to be laid in the laboratory as well as panels that have already been laid in floor coverings can be measured. There is no comparability between the slip resistance values R and the SRT values.
FSC 2000
A manufacturer from Ottobrunn built the first self-propelled measuring device (FSC 2000) that is approved in France and the Benelux countries. A motor drives an axle. The slider under the device creates a resistance whose coefficient of sliding friction can be transferred to a measuring strip and printed out immediately. A refurbished version has been available since 2003, which has minimized the so-called stick-slip effect .
GMG 100 & GMG 200
A new generation that works with a cable winch avoids the risk of wheels spinning that exists with the FSC 2000. The sliding friction measuring devices GMG100 and GMG200 thus meet the requirements of the DIN 51131 standard and are now used "on site" by the BGs, ie the statutory accident insurers. The measuring range of these devices includes class R9, other classifications in higher groups are not permitted. Analogous to this, barefoot areas below class A to class B. Only floor coverings with a small displacement space <V4 are measured with the GMG100 and GMG200.
Operators certified according to ISO or RAL can have their GMG100 or GMG200 calibrated by the manufacturer if necessary, but no later than once a year. The manufacturer GTE uses a calibrated test device. The annual calibration is a requirement of the respective quality management system (e.g. ISO 9001). Otherwise the user can decide when to calibrate. The GMG200 was developed and built for on-site measurements on behalf of the Accident Insurance (BGs), and only this device fulfills e.g. Currently the DIN 51131. GMG100 and GMG200 correspond to the DIN 51131 published in August 2008 (standard for device specifications and laboratory measurements).
FSC 3
The device is only listed on the manufacturer's website with a picture without additional text. The device works with an electric drive that moves the entire device over the ground at a defined speed. There are different gliders made of rubber, leather, plastic and other materials to measure the sliding friction on the surface to measure slip resistance. A coefficient of sliding friction is displayed. The dynamic coefficient of sliding friction between an integrated glider and the floor to be tested is measured (Schuster measuring principle). The coefficient of sliding friction is determined in the longitudinal direction. The measuring distance is z. B. 1 meter. The measurement results were recorded on measuring strips over the measurement section and the mean value was determined. Before the measurement, the test area should first be thoroughly cleaned and it is essential to remove dust with water before the measurement (construction site conditions). At the time of measurement, the surfaces should appear to be dry. An assessment of the slip-resistant properties of a floor can be made using the limit values proposed by the Bergische Universität-Gesamthochschule Wuppertal. Then the slip-resistant properties of a floor are classified as follows:
- Coefficient of sliding friction, anti-slip property:
- 0.00 - 0.29 uncertain,
- 0.30 - 0.44 conditionally certain,
- 0.45 - 0.64 safe and
- 0.65 - 1.00 very safe.
Current situation of national and international standards
A binding standard for the dynamic friction measurement procedure has been adopted in Germany. This DIN 51131 was printed and published in August 2008.
The standard says nothing about the evaluation of the measured values. The assignment of the measured values and their evaluation can be found in the rules and information of the employers' liability insurance association or statutory accident insurance. So z. B. in DGUV Information 208-041 (formerly BGI / GUV-I 8687) "Assessment of the risk of slipping under operating conditions", created by the subject area "Floors, ramps, stairs" in the structural facilities and managers of the trade and logistics department (FBHL ) of the German Social Accident Insurance (DGUV) (formerly Technical Committee for Structural Facilities), information on assessing the risk of slipping under operational conditions by testing the slip resistance. The basis for this are DIN 51131 and the GMG200.
The regulations of the professional associations and the statutory accident insurance have the status of extended insurance conditions and are therefore initially a purely German matter. They serve to implement the German Occupational Safety and Health Act and offer employers, employees and citizens in general legal security and protection.
Communities with a swimming pool are therefore subject to the regulations, rules and leaflets of the community accident insurance. Traders have to comply with the regulations, rules or leaflets of the respective professional associations.
Whether German measuring devices will ever be recognized in Europe or whether DIN 51131 will become EN is currently still completely unclear.
DIN CEN / TS 16165 describes and specifies various methods used in Europe to determine the slip resistance of floors. Among other things, the corresponding procedures according to DIN 51097 (walking barefoot on an inclined plane), DIN 51130 (walking on an inclined plane with shoes) and DIN 51131 ( tribometer test) are listed.
For Germany, DIN 51131 applies until an EN standard is published.
For Austria, ÖNORM Z 1261 accessible surfaces - measurement of the coefficient of sliding friction in buildings and in the open air of workplaces.
Stuttgart sliding measuring device
Measurements in the area of sports floors and sports facilities according to DIN 18032 and IAAF.
Disadvantages of measurements "on site"
A disadvantage is the high degree of manipulation with some devices. When installing i. d. R is the "R value"; an "on-site" device can be used for renovations. The manipulation of the new GMG and FSC devices is only possible with a great deal of technical effort. This can be recognized at the latest during calibration. However, manipulations on the slider or with the aid of falsifying lubricants are easily possible.
A research project at the University of Wuppertal, Department of Occupational Safety, has shown that there is no comparability between slip resistance values R and SRT sliding friction values. The medium of oil on the inclined plane shows different results than dry or water-wetted gliders. For a comparative measurement e.g. B. before and after a renovation, they are quite suitable.
Test methods abroad, other standards, rules and devices
In EN 1341, 1342 and 1343 (European product standards for floor coverings, stairs and pavement in outdoor areas for natural stones) SRT values are required, which are standardized in Europe, but are not recognized by the employers' liability insurance association . There are also new methods, such as B. a shoe simulator that was developed by the University of Wuppertal . In Italy and the USA there are also measurement methods that are not comparable with the inclined plane method.
Regulations for work areas
In 1987 the retail trade association published a leaflet with the designation ZH 1/571, in which the requirements of the trade association were specified. This included the test according to DIN 51130 with the requirement that the minimum requirement of the slip resistance value of R 9, which is not included in DIN, was added. After renaming to the professional association rule (BGR) BGR 181 and tightening of the minimum requirement in October 2003, this set of rules represents the recognized state of the art . In the last update, the outdoor areas were also included in the set of rules. Since then, BGR 181 has been called DGUV rule 108-003. The following are examples of the evaluation groups:
- R 9 applies, for example, to interior floor coverings in general areas (offices)
- R 10 applies to public toilets ,
- R 11 applies to store entrances and stairs outside as well as in kitchens for communal catering in dormitories, day care centers , sanatoriums
- R 12 applies in hospital kitchens and in kitchens in which more than 100 place settings are produced daily
- R 13 applies to floor coverings in slaughterhouses
The assessment groups of BGR 181 apply exclusively as minimum requirements for public spaces and flat surfaces. It doesn't mean that no one can slip on these surfaces.
Regulations for wet barefoot areas
The municipal accident insurance (GUV) is in charge of wet barefoot areas such as swimming pools and saunas . In the old GUV 26/17, today in the new GUV-I 8527, degrees of inclination were specified which are analogous to the BGR 181 guideline. Instead of evaluation groups for surefootedness with numbers, “ABC” values are determined here. DGUV Information 207-006 formulates requirements for floor coverings in wet barefoot areas in accordance with DIN 51097 and assigns the substrates to the assessment groups. See table above
Natural stone
Indoor areas
In order to achieve the required slip resistance of a floor made of natural stone indoors, the surface must have a corresponding roughness. The roughness can by means of grinding , chemical treatment , laser machining technical be achieved. The aim is to equip the surface with the necessary micro-roughness and to impair the appearance as little as possible. It should be noted that certification according to DIN 51130 must be carried out by an accredited testing institute or a corresponding CE mark .
Outdoor areas
Beflammte , bush hammered , sandblasted or similar rough machining of natural stone surfaces are traditionally used for outdoor applications and have proven themselves.
Ceramic surfaces
Indoor areas
The ground surface is possible for ceramics, but is rarely used. Porcelain stoneware can be lasered or chemically treated to achieve the slip resistance value of R 9 or more. The chemical treatment is mostly invisible or partly removes its shine from the surface. Another method to improve traction consists in coating with colorless, transparent lacquer in which quartz sand is sprinkled or is already contained. However, coatings have the disadvantage that they are worn off (beaten track). These areas then have to be improved from time to time. In most cases, structured surfaces are created directly by pressing the ceramic powder during production, which can reach the highest slip resistance value of R 13. For ceramics for wet barefoot areas i. d. Usually a special glaze is used. In contrast to a “thick layer glaze”, this is macrorough. This is due to the fact that this glaze has to be “sharp” so that the foot can hold it. This glaze is not very resistant to abrasive substances (shoe dirt). According to GUV 26/17 and its successors, this ceramic cannot be cleaned manually. Machine use, e.g. B. Roller brushes are ideal for this ceramic in conjunction with phosphate cleaners .
Outdoor areas
Here, the slip resistance is created by macrorough structures that are incorporated during the pressing process, before the ceramic tiles are fired. In addition to spray adhesives, adhesive strips and foils with a sand-gray surface, there are also plates and strips made of plastic or metal (also for ladders and steps) with granulate or even single slag welded on, etc., to improve the slip resistance, etc. Depending on the problem and requirement as well as optical concessions there is an optimal solution for every requirement whereby these are usually also visually recognizable on purpose.
Glass shelves
There are various methods of creating slip protection for glass floors , sandblasting being one of the most common. The disadvantage is that sandblasted glass cannot be cleaned manually. It works by machine i. d. Usually only with spray extraction devices. Silicatic coatings are easier to clean and run more smoothly than other coatings. Flat glass, which is also called float glass , requires laser processing with special lasers, the Nd: YAG lasers , which are patented by a German company. Similar to screen printing , micro-rough patterns can also be “embossed” directly during flat glass production
Utility screeds
Usable screeds , such as magnesite screeds or epoxy resin-coated cement screeds , can be made slip-resistant by sprinkling hard materials such as quartz sand when they are introduced into the building in interior areas up to a slip resistance value of R 11.
Cast stone
Concrete stone (BTW) and terrazzo are offered for indoor areas in mostly polished form. This is enough i. d. Usually for the required slip safety value of R 9. In outdoor areas, there are concrete slabs that are sandblasted or slabs made of exposed aggregate concrete .
Resilient floors
In addition to PVC , linoleum and rubber coverings, polyolefins are also among the coverings that must be checked for slip resistance.
Further topics on non-slip surfaces
Standards and pre-standards for slip resistance in the interior
- Wood
- CEN / TS 15676 Wood flooring - Slip resistance - Pendulum test
EN and DIN standards for slip resistance in outdoor areas
- concrete
- EN 1338 concrete paving stones
- EN 1339 concrete slabs
- EN 1340 curbs made of concrete
- Paving bricks
- EN 1344 paving bricks
- Natural stone
- EN 1341 natural stone panels for outdoor areas
- EN 1342 natural stone paving stones for outdoor areas
- EN 1343 curbs and edging stones made of natural stone
- So-called. Residual norms that continue to apply
- DIN 482 road curbs made of natural stone
- DIN 483 curbs made of concrete
- DIN 18503 paving clinker
Individual evidence
- ^ German Statutory Accident Insurance eV (DGUV): Arbeitsunfallgeschehen 2018. Retrieved on April 22, 2020 .
- ^ Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA): IFA test laboratory for the sliding safety of floor coverings. Retrieved April 22, 2020 .
- ^ German Social Accident Insurance eV (DGUV): DGUV Information 208-041 - Assessment of the risk of slipping under operating conditions. Retrieved April 22, 2020 .
- ↑ German Social Accident Insurance eV (DGUV): DGUV rule 108-003 - Floors in work rooms and work areas with a risk of slipping. Retrieved April 20, 2020 .
- ^ German Social Accident Insurance eV (DGUV): DGUV Information 207-006 - Floor coverings for wet barefoot areas. Retrieved April 22, 2020 .
- ↑ www.cen.eu
Web links
- Slip safety in work rooms and work areas with a risk of slipping for download (BGR 181) (PDF; 339 kB)
- Technical article on measurement methods, part 1, for download (PDF; 1700 kB)
- Technical article on measurement methods, part 2, for download (PDF; 1300 kB)
- Special document of the Federal Institute for Occupational Safety and Health on the assessment of the slip resistance of floors for download (PDF)
- BAuA technical article on slip safety on stairs for download (PDF; 509 kB)