The pendulum test, in plain English.
Plus the numbers that actually matter.

What the pendulum test actually does

The pendulum friction tester is a portable piece of kit that swings a weighted arm with a rubber pad at its tip. The pad sweeps across a 126 mm length of the floor. The friction between the rubber and the floor slows the arm. The pointer records how far the arm continues to swing after the contact. The less it continues, the more friction, the higher the slip resistance. The number you get is the Pendulum Test Value, or PTV.

The PTV scale — what the numbers mean

Wet PTV	Classification	What it means
36+	Low slip risk	HSE-accepted benchmark for acceptable slip resistance on level pedestrian surfaces.
25–35	Moderate risk	Borderline. Investigate further. Specific remedial action likely needed.
0–24	High slip risk	Dangerous in wet conditions. Immediate action required.

This scale applies to level pedestrian surfaces. Ramps, steps and barefoot areas have different thresholds — but PTV 36 in the wet with a Slider 96 is the baseline number every UK slip-safety conversation references.

The four questions every pendulum test has to answer correctly

1. Which slider? Slider 96 (Four-S) for standard shod pedestrian areas. Slider 55 (TRL) for barefoot areas and soft, compliant surfaces. Using the wrong slider invalidates the result.
2. Dry or wet? Both, usually. Most slip accidents happen on wet floors. A dry-only test tells you almost nothing.
3. What contamination? Water is the default. But if the floor sees grease, oil or other contaminants in service, the test should replicate that.
4. Where on the floor? Slip risk varies across a floor — entrance zones differ from main floor, from the area near a drink dispenser. A competent survey tests representative locations.

Which standards apply

Three documents govern UK pendulum testing in 2026:

• BS EN 16165:2021 (Annex C) — the current UK and European standard for pendulum slip testing. Superseded BS 7976 in February 2022.
• UKSRG Guidelines Issue 6 (Jan 2024) — the operational protocol UK testing laboratories apply when running a pendulum test. Defines slider conditioning, water contamination, reporting requirements.
• EN 13036-4 — the pendulum method for highway / road surfaces. Used in parallel with EN 16165 for outdoor pedestrian areas.

Why UKAS accreditation still matters for the pendulum

The pendulum is a precision instrument, and a UKAS lab has independently demonstrated competence to operate it correctly. Non-accredited operators frequently make one or more of these errors:

• Using a slider past its valid life (sliders degrade with use and must be discarded)
• Applying water inconsistently or at the wrong volume
• Testing on a surface that's fundamentally unsuitable for pendulum testing (some micro-profiled surfaces cannot be validly tested with this method)
• Failing to record the 5-swing mean correctly (the test requires 5 swings, not a single reading)
• Reporting a single PTV number without stating measurement uncertainty

Any of these renders the result unreliable. Courts, insurers and regulators know this. They treat UKAS accredited results as the baseline and everything else as suggestive at best.