Floor Slip Resistance — R Ratings & Pendulum Test

Slip-resistance ratings for floors — what R-values and pendulum tests really mean

By Rayson Technical Team · Reviewed July 2026

Floor slip resistance is specified through recognised test methods, not adjectives: the ramp test that assigns R-ratings (R9 to R13), and the pendulum test that measures a slip-resistance value on site — the approach Singapore's own wet-floor slip standard is built on. Two honest caveats matter: a rating describes the surface as tested, and slip resistance changes in service as texture wears and contamination builds. Specify the rating for the zone's real conditions, then keep it through cleaning and maintenance.

Technician testing the slip resistance of a completed floor surface

“Anti-slip” is a claim; a slip-resistance rating is a measurement. When a specification, an insurer or a safety officer asks whether a floor is safe enough, the conversation runs on two recognised test families — and knowing what each does (and does not) tell you is the difference between specifying safety and specifying a word.

The ramp test and R-ratings

The R-rating system comes from a laboratory ramp test. A test surface is mounted on an adjustable ramp, coated with a standard contaminant, and an operator in standard footwear walks it as the angle increases. The angle at which slipping begins assigns the class — from R9 (the lowest class in the system) to R13 (the highest). Two things follow from how the test works:

It is comparative, not absolute. R11 means “more slip resistance than R10 under the test conditions”, not “safe in your kitchen”.
R9 is not ‘non-slip’. It is the entry class of the scale — a common misunderstanding in specifications.

R-ratings are useful shorthand for comparing systems and matching a texture grade to a duty, and they are how textured systems such as Rayson GripSafe AP12 profiles are typically discussed at specification stage.

The pendulum test — measurement on the real floor

The pendulum test swings a standardised rubber slider across the installed surface and reads a slip-resistance value from how much the surface slows it. Because it can be carried out on the actual floor — new or old, wet or dry — it is the tool used for site verification, periodic checks and disputes, and it is the method Singapore’s wet-floor slip-resistance standard is built around. Where a ramp rating describes a product, a pendulum reading describes your floor, today.

The two caveats that keep specifications honest

A rating describes the surface as tested. Real floors carry real contaminants — cooking oils, soap films, process dust — that can defeat a texture which performs well clean. Specify against the zone’s realistic worst condition, not the showroom condition.

Slip resistance is perishable. Traffic polishes texture; cleaning regimes that are too gentle leave films, and regimes that are too aggressive erode profile. A floor that tested well at handover can drift out of its intended performance in service — which is why wet, heavy-traffic areas deserve periodic re-testing, and why texture choice must be paired with a cleaning method the operator will actually sustain.

Specifying by zone

The practical method mirrors good flooring practice everywhere: map the zones by their wet and contamination reality, assign heavier texture only where conditions demand it, and keep smoother, easily cleaned finishes where floors run dry. For how texture interacts with washdown hygiene in food facilities, see food factory flooring in Singapore; for the systems themselves, start at anti-slip flooring Singapore.

Frequently asked questions

What does an R10 or R11 floor rating actually mean?

R-ratings come from a laboratory ramp test: an operator walks on the surface, coated in a standard contaminant, as the ramp angle increases, and the angle at which slipping starts sets the class from R9 to R13. Higher numbers mean more slip resistance under those test conditions. It is a comparative laboratory class — useful for specification, but not a measurement of your floor in service.

What is the pendulum test and why is it used on site?

The pendulum test swings a standardised rubber slider across the floor and reads how much energy the surface absorbs, giving a slip-resistance value. Its strength is that it can be run on a real installed floor, wet or dry — which is why it is widely used for verification and disputes, and underpins Singapore's wet-floor slip-resistance standard.

Does an anti-slip rating last for the life of the floor?

No — and any supplier who implies it does is overselling. Texture wears under traffic, polishing the peaks that grip a shoe, and contamination like grease films can defeat texture that tests well when clean. Slip resistance in service is a property of the surface plus its maintenance, which is why heavy-use wet areas should be re-checked periodically.

Should I just specify the highest rating everywhere?

No. Aggressive texture is harder to clean and holds soil, so over-specifying in a hygiene-critical dry area creates a different problem. Match the rating to each zone's realistic wet/contamination condition — heavier profile where floors run wet or greasy, cleanability where they run dry.

Products mentioned

GripSafe acrylic

Rayson GripSafe AP12

Rayson GripSafe AP12 is a one-pack, self-crosslinking acrylic primer filler loaded with 0.5–1.5 mm silicate quartz aggregate that builds an anti-slip texture directly onto concrete and asphalt.

Surfaces: concrete, cement screed
Role: primer

View product

PurScreed pu cement

Rayson PurScreed PC70

Rayson PurScreed PC70 is a four-part, water-based polyurethane-cement self-smoothing screed installed at 1.5–3 mm for medium to heavy-duty industrial floors with high chemical resistance.

Surfaces: concrete
Role: body coat