Here is the situation in one paragraph. Flooring is marketed on R-values. Slips are investigated on pendulum values. The two come from different tests, they do not translate neatly into each other, and the gap between them is where bad specifications (and accidents) live. If you specify commercial floors and you only remember one thing from this page, make it this: ask for the pendulum figure, wet.

The R-value: what it is, and what it is not

The R rating (R9 to R13) comes from the German ramp test, DIN 51130: an operator in standard boots walks on an oil-smeared sample as it tilts, and the angle at which they slip sets the class. It is a legitimate factory measure, and it is how most safety flooring is labelled.

What it is not is a guarantee about your corridor. The scale starts at R9, which sounds reassuring but is the lowest classification, roughly what any ordinary dry-area floor achieves. The steps between classes are broad, the test uses oil rather than the water your floor will actually meet, and it says nothing about what happens after five years of the wrong mop.

  • R9, ordinary dry interiors. Not a wet-area floor.
  • R10, the sensible commercial baseline; standard safety-flooring territory.
  • R11-R12, kitchens, back of house, wet processes, ramps.
  • R13, heavy grease and industrial wet work.

The pendulum: the number the HSE trusts

The UK's preferred measure, used by the Health and Safety Executive and the UK Slip Resistance Group, is the pendulum test (BS 7976). A weighted rubber slider swings across the floor and the drag it feels comes out as a Pendulum Test Value. Unlike the ramp test, it can be run on your actual floor, wet, today, which is exactly how it is used in slip investigations and in court.

  • PTV 36 and above, low slip risk. This is the benchmark to specify for wet or high-risk areas.
  • PTV 25-35, moderate risk.
  • PTV 24 and below, high risk; roughly one slip in twenty passes on a wet floor.

The practical consequence: a floor can carry a respectable-sounding R rating and still pendulum poorly when wet. When a datasheet shows both figures, believe the pendulum. When it shows only an R-value for a wet area, ask why.

What to specify, space by space

  • Healthcare, Health Building Note 00-10 territory: impermeable sheet, coved skirtings, welded seams, and slip resistance held even when the cleaning regime is aggressive. PTV ≥ 36 in wet-risk areas.
  • Commercial kitchens, R11 minimum in practice, R12 where grease is constant; installed to falls, coved, with thresholds sealed. Specify the pendulum figure wet and contaminated.
  • Schools, safety grades in circulation, science, changing and shower areas; standard contract floors elsewhere. The specification difference is pennies against the risk.
  • Entrances and concourses, the first five metres inside a door do more for slip safety than any rating: proper entrance matting strips water off feet before it reaches the floor.
  • Stadiums and venues, outdoor-to-indoor transitions, spilled drinks and crowds moving at pace: safety sheet on concourses and hospitality, pendulum-checked wet.

The part datasheets do not mention: installation changes the number

Two floors, same product, same rating. Five years on, one still grips and one does not. The difference is rarely the manufacturer. It is:

  • The subfloor. Moisture coming up through a slab lifts adhesion and opens seams. We hygrometer-test to BS 8203 before ordering a metre of anything, and price the damp-proof membrane in from the start if the slab needs one.
  • The seams and edges. Safety flooring earns its keep as one sealed surface, hot-air welded joints, skirtings coved up the wall. An unwelded seam in a wet area is a slip hazard with a warranty dispute attached.
  • The maintenance. This is the quiet killer. The wrong polish or a lazy mop-and-bucket routine fills the slip profile with a film of residue, and the floor's real-world PTV sinks year by year while its datasheet stays perfect. A safety floor needs a maintenance regime written for safety floors, which is why we run one.

A one-minute checklist for your next specification

  • Wet-risk area? Specify PTV ≥ 36 wet, not just an R class.
  • Kitchens and grease: R11-R12 and pendulum-checked with the actual contaminant.
  • Healthcare: welded, coved, impermeable, HBN 00-10 language.
  • Ask how the subfloor will be moisture-tested, and to what standard.
  • Ask who maintains it, with what products, and what that does to the grip.
  • If a quote is oddly cheap, the subfloor prep or the welding is usually where it went missing.

If you would rather just describe the space and have the specification done for you. That is the job. Tell us about the building, or call the office on 020 8395 6009.