Anti-slip for gratings and stair treads: standards, options, and advice

European test method: CEN/TS 16165 

Within Europe, the slope test method is laid down in CEN/TS 16165. This measures the sliding behavior of a test block on a sloping surface. The results are expressed in the same R value scale as DIN 51130. This makes the standards comparable and widely applicable in European projects.

Materials and finishes for anti-slip

The slip resistance of a grating or stair tread depends not only on its shape, but also on the material used and how it is processed. Important factors are described below.

Serration

Machined serrations or notches on bearing and/or filling bars significantly increase slip resistance. 

Perforation

Perforated panels with slip-resistant properties offer grip in multiple directions. Examples include:

• Perforated panels AP 30/40/50: panels with round holes with raised edges;
• Perforated panels SER: specially developed for extra grip in multiple directions.

Materials

Depending on the application, you can choose from:

• Galvanized steel (S235): robust and durable
• Stainless steel: high corrosion resistance, optionally with coating
• Aluminum: lightweight, R12 possible with proper processing

Corrosion protection

Depending on the material and application, various methods are available:

• Hot-dip galvanizing (DIN 1461)
• Anodizing (for aluminum)
• Primer and anti-slip coating (for steel/stainless steel)

Difference between R classes and PTV values

In practice, R classes (DIN 51130) are regularly compared with the Pendulum Test Value (PTV), a British test method (according to BS 7976). Both methods measure slip resistance but use different principles.

R classes are determined by means of a slope/ramp test with oil and weighted safety shoes. The test person walks on a sloping surface until slipping occurs. The critical angle of inclination determines the R value (R9 to R13). This method is suitable for industrial applications, particularly where grease or liquids are present.

PTV values are determined using a pendulum test. In this test, a rubber shoe swings over the test surface and the friction is measured. The higher the value, the less chance of slipping. The interpretation is as follows:

• PTV < 25: high risk
• PTV 25–35: medium risk
• PTV > 36: low risk

Where R classes are suitable for oily or industrial environments, PTV values are more reliable for slippery, wet outdoor floors or public spaces. The PTV test is also more accurate in barefoot situations or on surfaces that are not used on slopes.

At Staco, we mainly use the R classification, as it is most relevant for gratings, stair treads, and industrial applications. Upon request, we can provide additional information about the PTV value of specific products.

Anti-slip in practice: which type for which environment?

When selecting the right R class, a risk analysis is essential. This analysis considers:

• Usage situation (indoor/outdoor, dry/wet, oil/grease)
• Degree of contamination
• Users' footwear
• Slope or flat surface
• Maintenance frequency and drainage

Some practical guidelines:

• R9–R10: dry indoor areas with limited traffic
• R11–R12: intensively used stairs, kitchens, workshops
• R13: industrial areas with oil or liquids, slopes

Gratings with deep serrations require slightly more maintenance but offer maximum grip. Perforations are suitable for situations with drainage requirements.

Standards we comply with

Staco gratings and stair treads are designed and manufactured in accordance with:

• DIN EN ISO 14122-3: safety of access systems
• DIN 24537: technical specifications for metal stair treads
• BGR 181 / BGI 588: slip resistance guidelines for work floors
• NEN 7909 / CEN/TS 16165: test methods for slip resistance
• DIN 1461: galvanizing standard for steel products

Our products are tested according to the relevant requirements and certified with the correct R classification.