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What PTV does your floor need? Minimum slip values by area

“Is my floor slippery enough to be a problem?” The honest answer depends on where it is and how it’s used. Here are the PTV targets for level floors, ramps and wet barefoot areas — and the slope rule done properly.

Level floors

For an ordinary level floor, the target is a PTV of 36 or above in the floor’s normal operating condition. For a floor that is normally dry, that means 36+ dry; for a floor that gets wet, it means 36+ wet. There isn’t a separate “minimum” for kitchens versus receptions versus shops — the 36+ principle applies across the board. The real work is judging the condition the floor actually sees, and the contamination it has to cope with.

Ramps and slopes

A slope makes a floor effectively more slippery, so the target rises with the gradient. The increase is not a flat “one point per degree” — it follows the tangent of the angle.

The slope rule: the extra PTV a slope needs is 100 × the tangent of the slope angle. Small slopes add little; steeper ones add a surprising amount.

Worked examples: a 1° slope (often used around pools for drainage) needs about 2 extra PTV, so the low-risk threshold becomes 38+. A 5° slope — the steepest allowed for a ramp under UK accessibility guidance (BS 8300:2018) — needs about 9 extra, so the threshold becomes 45+. Slopes steeper than about 10° call for PTVs that flooring rarely achieves when wet.

Slip potentialLevel floor1° slope5° slope
High0–240–260–33
Moderate25–3527–3734–44
Low36+38+45+

Wet barefoot areas

Showers, changing rooms and pool surrounds are walked on barefoot and should be tested with the barefoot slider (Slider 55, called Slider 57 in BS EN 16165), not the shod slider. A floor that is fine underfoot in shoes can behave very differently under a wet bare foot, so the slider has to match the way the floor is really used.

It’s a risk assessment, not a lookup

A PTV is a snapshot, and a single number isn’t the whole answer. The UKSRG is explicit that a result should feed into a risk assessment weighing the surface, the likely contamination, the footwear, the task and the cleaning regime — and that you should look at the lowest reading, the worst case, not just the average. Slip resistance also changes over time with wear, contamination and cleaning, so periodic re-testing is the sensible approach for higher-risk areas. When specifying a new floor, the manufacturer and a flooring specialist should be involved; the pendulum is how you prove what you have actually ended up with.

KSS
Written and reviewed by the Knightcott Surface Solutions team.
KSS is a UK manufacturer of Pendulum slip-resistance testers, named as a manufacturer in the UK Slip Resistance Group’s published Guidelines. Our director, Ian Roberts, is Secretary of the UKSRG, and our senior calibration engineer contributed to the current (Issue 6) Guidelines. We calibrate, test and train on these instruments every day. This guide is general information, written with reference to the UKSRG Guidelines (Issue 6), and isn’t a substitute for a site-specific risk assessment.

Frequently asked questions

What is the minimum PTV for a level floor?

A PTV of 36 or above in the floor’s normal operating condition — wet for areas that get wet, dry for areas that genuinely stay dry.

What PTV does a ramp need?

Start from 36 and add 100 × the tangent of the slope angle. A 1° slope needs about 38+, and a 5° ramp — the UK accessibility maximum — needs about 45+.

Is there a different minimum for kitchens, pools or shops?

The 36+ principle is the same everywhere. What changes is the condition you test in (wet for areas that get wet) and the slider (the barefoot slider for barefoot areas). It is a risk-assessment judgement, not a per-room lookup table.

How often should a floor be re-tested?

Periodically for higher-risk areas. Slip resistance drops with wear, contamination and changes to cleaning, so re-testing is how you catch a floor before it becomes a problem.

Not sure what your floor needs?

Tell us where the floor is and how it’s used — we’ll test it and tell you exactly where it stands against the right target.