Key points
- The R class (R9-R13) comes from the DIN 51130 laboratory ramp test on a new, oil-coated sample.
- PTV is the result of the pendulum test to PN-EN 13036-4, which can be done on an installed floor, dry and wet.
- Polish ITB guidelines and the Ministry guide point to the pendulum and a 36 PTV threshold for floors in public buildings.
- PTV and R classes cannot be converted directly: they come from two different test methods.
Tiles and stone carry two slip resistance scales. The R class (R9-R13) comes from the laboratory ramp test to the German standard DIN 51130. The PTV (Pendulum Test Value) is the result of the British pendulum test to PN-EN 13036-4, which can be carried out on a finished floor in use. Since 2018 it is the pendulum test and the 36 PTV threshold that the Polish Ministry of Investment and Development guide sets for buildings accessible to people with disabilities. Below we explain how the two scales differ and when to use which.
What is the R class under DIN 51130?
The ramp test takes place in a laboratory. A tester in safety shoes walks forwards and backwards on a sample coated with motor oil. The ramp starts level and its angle increases until the tester can no longer walk safely. That angle sets the slip resistance class.
| Class | Ramp angle | Slip resistance |
|---|---|---|
| R9 | 6° to 10° | lowest |
| R10 | over 10° to 19° | low |
| R11 | over 19° to 27° | medium |
| R12 | over 27° to 35° | high |
| R13 | over 35° | highest |
Each class covers a wide range of angles, so two R10 tiles can behave quite differently. The test also describes new material: it says nothing about how the floor will behave after months of heavy use. According to ITB, a test on a sample coated with motor oil may not be relevant for buildings other than industrial ones.
Classes A, B and C for barefoot areas (DIN 51097)
For areas walked on barefoot (pools, showers, changing rooms) there is a separate ramp test to DIN 51097: the tester walks barefoot on a sample wetted with water and detergent.
| Class | Minimum ramp angle |
|---|---|
| A | 12° |
| B | 18° |
| C | 24° |
What is PTV and the British pendulum test?
The test is done with a portable pendulum. An arm with a rubber slider imitates a pedestrian's heel striking the floor, and the friction between the slider and the surface is expressed as the PTV. The slider and test conditions are chosen for how the surface is used: walkways used in shoes are tested differently from barefoot areas. The method is described in PN-EN 13036-4.
The result is read against the classification of the UK Health and Safety Executive (HSE):
| PTV | Slip risk |
|---|---|
| 0-24 | high |
| 25-35 | medium |
| 36 and above | low |
For comparison: at 19 PTV the chance of slipping is estimated at 1 in 2, and at 36 PTV at about 1 in a million. The table is a reference band, not an assessment of compliance with regulations: a result always refers to the test conditions.
What PTV values are required in Poland?
Two documents in Poland point to the pendulum test:
- Building Research Institute (ITB) guidelines for public buildings: at least 36 PTV dry and wet in entrance areas, walkways, sanitary rooms, retail and service areas, on terraces and balconies and in rooms exposed to water; 80-110 PTV dry for sports floors. Slip resistance should be tested every 5 years.
- Ministry of Investment and Development guide "Design standards for buildings for people with disabilities" (2018): a wet slip value of no less than 36 PTV throughout the life of the surface, checked at least every 3 years.
The full overview of regulations and areas is on the Knowledge: regulations and PTV page.
PTV vs R class: can they be compared?
Not directly. The two scales measure different things, with different methods and in different conditions: the R class is the ramp angle for a new oil-coated sample, the PTV is the friction of a slider on a wet or dry floor, often one already in use. That is why there is no reliable conversion table. The R class helps compare tiles in a catalogue; the PTV tells you how slippery a particular floor is today.
Pros and cons of the ramp test
- Compares floor materials and footwear under repeatable laboratory conditions.
- Manufacturers state the result in tile data sheets.
- Each class covers a wide range of angles, so the reading is approximate.
- Needs a sample tested in a laboratory; it cannot be done on an installed floor.
- Tests only a surface contaminated with oil (or water and detergent in DIN 51097).
- Says nothing about how long the slip resistance will last in use.
Pros and cons of the pendulum test
- Gives results both dry and wet.
- Can be done in a laboratory and on site, on an installed floor.
- Can test small samples and assess a floor after years of use.
- Imitates walking in shoes or barefoot, depending on the slider.
- Recommended by the Building Research Institute, the National Labour Inspectorate and the Ministry guide.
- Testing many points in a large building takes time.
Which scale should you use?
- Designing or buying a new floor: check the R class (and A/B/C for barefoot areas) in the data sheet, but also ask for the wet PTV, because that is what Polish guidelines refer to.
- Managing a building, preparing a handover or an inspection: order an on-site pendulum PTV test. The report documents the condition of the floor.
- The result is below 36 PTV: the floor can be cleaned and given an anti-slip treatment, and the effect confirmed with another test.
Frequently asked questions
It is the result of the DIN 51130 laboratory ramp test. The higher the class, the steeper the ramp at which a person in safety shoes on an oil-coated surface keeps their footing: R10 means over 10 to 19°, R11 over 19 to 27°.
