Decking is one of the highest-risk external surfaces when wet — rain, shade and algae can drop a smooth board well below a safe level. We test boards exactly as supplied, smooth or grooved, to show how they actually perform underfoot in the wet rather than how they look in a brochure.
Where it's used: Garden decking, balconies, jetties, boardwalks, pub and restaurant terraces.
Tested wet with the 4S slider, usually both along and across any grooves — direction of travel changes the result on profiled boards.
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The pendulum simulates a heel strike. The higher the value, the lower the chance of slipping. UK courts, the HSE and the UK Slip Resistance Group all read results against the same bands.
High slip potential. Roughly a 1-in-20 chance of slipping or worse — generally unacceptable for pedestrian use when wet.
Moderate slip potential. A meaningful risk that usually needs control measures or a better surface.
Low slip potential. The widely accepted target for level pedestrian surfaces in the wet.
Barefoot wet areas (e.g. pool surrounds, changing rooms) are assessed with the TRL/55 slider against separate criteria. We confirm the correct slider and conditions for your product before testing, and can also measure surface roughness (Rz) as a supporting indicator.
Our scope of accreditation covers the pendulum methods relied on across UK and European flooring specification, litigation and product approval.
The core British Standard governing how the portable pendulum is operated and calibrated for slip resistance measurement.
The European standard consolidating slip resistance evaluation methods, including the pendulum (Annex C) for surface products.
Pendulum measurement applied to road, pavement and external surfacing — relevant to paving and external products.
The interpretation framework that turns raw PTV figures into the slip-potential classifications used in reports and disputes.
Tell us about your product and its intended use. We'll confirm the method, price and where to send your sample.
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